Category Archives: Maple Production Tips
Les Ober OSU Extension
I got up this morning and it was 60 degrees. All I could think of was that a lot of my friends who make maple syrup got up, saw the same thing I did and headed straight to the sugarhouse to find their drills. To say the least this is unusually warm for this time of year and it has everyone scratching their head. I also looked at the internet and questions were coming into the OMB about whether it is time to tap. This is topic that will be address in depth at the Ohio Maple Days but due to the early warmup I will give you my take on the subject.
First a little science! To quote New York Maple Specialist Steve Childs we need to know “How Does Sap Happen”. Sap flow is the result of sap rising and falling in the tree through the vascular system of a maple tree known as sapwood. The sap flows to provide nutrients to all of the vegetative growth above ground. Sap flow from the roots to very tips of the branches nourishing the buds that will develop into leaves. This process is on a phonological clock that limits the amount of time that we have to intercept a very small portion of that sap and make it into maple syrup. Once the buds emerge the sap is no longer useable for syrup production. Sap rises because of a variation in spring temperatures that we call the freeze thaw cycle. The tree freezes, this creates a suction that draws nutrients from the roots along with ground water. Once the temperature rises above 32 degrees F, gases begin to form inside the tree. This pushes the sap up the sapwood the tree up into the very tops of the branches. Considerable pressure is produced in the process. In fact that pressure can reach 40 psi. When you drill a hole in the tree sap leaks out into a bucket and continues until the tree quits pushing sap or it freezes again. We can increase that flow by applying vacuum to the tap with a vacuum pump and tubing. If the temperatures stay warm sap flow will gradually decline. Sap can flow up to 72 hours without the repeat of the freeze thaw cycle. Without freezing the sap level in the tree drop below the taphole and the flow will stop. Once the temperatures drop below freezing the whole cycle starts again. This is a very simple explanation of a very complex process.
What else can cause sap to stop flowing from a taphole? Once a taphole is drilled into a tree the maple season clock starts to run. With buckets and open tap holes that window of opportunity is around 4 weeks before the taphole starts to heal up and the sap flow stops. This healing is the result of the taphole being exposed to air and from the growth of bacteria in and around the hole. Air dries out he taphole and supplies oxygen to bacteria that coat the hole with slime that eventually seals off the exposed sap wood. Similar to what happens when you get a cut. Blood flows for a while but eventually it coagulates and the bleeding stops. A vacuum tubing system is different in that the taphole is not exposed directly to the outside air and sap is kept flowing under vacuum for a longer period of time. If operated correctly the hole will be kept free of bacteria for most of the season. This can be accomplished two ways. First you can keep the vacuum running continuously whenever the air temperature is above freezing. This will keep the sap moving keeping the lines clear and the taphole cool. Producers have found that they will gather enough sap during extended warm periods and make enough syrup to pay for the cost of running the pumps during that period of time. The other method is to us a vacuum system with check valves to prevent bacteria laden sap from the lines being pulled back in the tree. A tree will draw sap from the lines just like a hose will siphon water from a tank when you turn the tap off. This bacteria laden sap will aid in healing and shutting down the taphole for the season. The check valve will close when the vacuum is released and it will seal off the tap. I discussed many of these taphole sanitation techniques along with the use of check valves in an earlier post on this blog. A side note; for those of you using a 3/16 gravity system, research at the Cornell Maple Program, shows that because you are generating a higher level of vacuum a pull back into the tree occurs. Preliminary research shows that using a check valve will increase the yield in a 3/16 tubing gravity system. I intend to discuss 3/16 tubing in an article to be published on the OMB at a later date.
Now to answer the question should I tap or not tap during and early warms spell. My suggestion is to obtain all the information you can about upcoming weather patterns. Then look at your system. If you are a small producer or a backyard producer looking for the ideal 30 day window, January is most likely too early to tap. Your taps may dry out and you may miss some of the really good runs in late February or March. You could re-tap but that is hard on the tree and is never recommended. The best approach is to watch the weather and be ready to get those good runs in February and March. For those of us who have vacuum tubing. We can stretch the season with taphole sanitation techniques. Watch the weather and tap when to opportunity arises. You may get some very good early runs. If you are going to tap now make sure you change out your spouts or use check valves. You have to create a closed system at the tree to prevent taphole healing. If you have enough taps consider tapping the side of the woods that runs early now and the late running sections later on, spread the season. The best you can hope for is two months before your taps start to shut down. I have personally kept my taphole open from the 10th of February to the 10th of April with the use of check valves and continuous vacuum operation. No matter what you decide to do it is a gamble, here’s hoping your decisions pays off. Here is a little additional information that may help to make you decide. NOAA Weather has now released their 3 month forecast for January, February and March. It is now calling for above normal temperatures during the period for Ohio into New England. I will hedge a little but my taps will be in by February 1st.
On December 7th we launched a new addition to the Ohio Maple Blog. It is called “Its Not Just for Pancakes Anymore.” One of the main reasons for the new addition is to reach out to maple syrup consumers and give them an educational resource dedicated to the use of Maple syrup and maple products. In the first addition we are talking about the new international grading system for maple syrup. Many consumers are use to the old USDA Standard System but what they may not realize is that this system has been replaced. The new system not only grades syrup by color but also by flavor. This takes maple grading to a new level utilizing multiple senses. I also brings it to a level that consumers understand. May of the food product industries employ the sense of sight, taste to define the quality of their products. The maple industry has now reached that level.
In the months ahead we will be exploring the topic of grading and quality assurance on this blog. An understanding of how the process of making maple syrup will affect not only the density, color and flavor will improve the quality of your product.
Geauga County OSU Extension
Two years ago this Fall the maple syrup industry completed the adoption of a new system for grading syrup. It took a long time to get everyone on the same page to complete the process that was officially started in 2011. The International Maple Syrup Institute took the old USDA Standard grades that included USDA Grade A Light, Medium and Dark and Grade B and transformed them into four Grade A categories that would include all saleable syrup. Two important additions were the flavor descriptors and the Tc (light transparency) range. This allows consumers to compare grades on flavor and it also opened the door for the use of instruments in the grading process for color determination.
The four Grade A categories are Golden Delicate, Amber Rich, Dark Robust and Very Dark Strong. You will find that Golden Delicate parallels the old Light Amber Category. Amber Rich includes all of the old medium and the very top of the Grade A Dark Category. Dark Robust includes the rest of the of the Grade A Dark category and the very Top of the old Grade B Category. The Very Dark Strong Category includes the rest of the syrup that was formally classified as cooking syrup. Most very dark syrup that is produced and does not have an off flavor or a density problem will fall in this category. If syrup has an off flavor or does not meet the above minimum of 66 brix, or the below maximum 68.9 brix density standard it will be sold as commercial syrup and priced accordingly. It should be pointed out that the retail price in most markets does not change for any of the top 3 grades and many producers sell their very dark syrup for the same price.
The new grading system allows us to not only sell syrup on color but also on flavor and after all, flavor is what sells maple syrup. Flavor is a component of maple syrup judging that is very subjective. Everyone has their own idea of what maple syrup should taste like. It is almost unfair to put maple syrup in a jug that has not been graded. It would be like labeling a cut of meat as beef. You as a consumer would be buying the package of meat and not know if it was a Porterhouse Steak or Stew Meat. That type of marketing went out the window with the anticipation of finding out what the prize was in a box of Cracker Jacks. Today’s consumers are getting smarter about what they buy. Why would you try to sell them syrup that could be Very Dark Strong, Golden Delicate or something in-between? If you are just putting syrup in a jug you are missing out on an important part of marketing, interrupting and understanding what the consumer truly wants. You maybe marketing high grade of Golden Delicate syrup when the consumers is looking for a darker more robust flavor. The comment you often hear about Golden Delicate is that it is very sweet with little or no maple flavor. If this were case, do you think you will have a return customer; even though you put what you believe is your best product in the container?
There is however, one caution about selling graded maple syrup; it had better be graded right. That is where spectrophotometry comes in. Today for 60 to 80 dollars you can buy a Hanna Checker. There is also a more accurate and expensive model available for commercial packers, contest and grading fanatics. It is all based on the transmission of a beam of light through the sample. As the product darkens the percent light transmission drops. Once you have a reading you match the %Tc light transmission reading on the device to the %Tc range of one of the new grades. Each grade has a % Tc range. The end results are similar but a lot more reliable than a temporary grading kit. Over the last two months putting, together my maple syrup evaluation programs, I have had a chance to look at dozens of samples of maple syrup, some graded and some not. Many times these samples were so close it would be impossible to grade accurately on a hand held temporary grading kit. This new instrumentation makes it easy to grade syrup. This proves once again that maple syrup production is pure science from start to finish.
Generally overall the new grading system has been well received at various locations where we introduced it to the public. At many fairs and shows we have been able to stimulate conversation about the characteristics of each individual grade. Using sample tasting is a great way to interact with your customers. Generally overall potential consumers liked Amber Rich but more and more are trying and enjoying Dark Robust. This has been a learning experience for both the producer and the consumers alike. Ultimately I think many of the producers end up learning a little more about consumer preferences and the product they are selling. Grading in many states is not mandatory and Ohio is one of them. The other factor here is that consumers are really not familiar with how maple syrup is graded. The only thing they can compare it to is your average table syrup which has no identity. This is where maple producers can take a lesson from the wine and craft beer industry. They have built a whole marketing program around identifying the various characteristics of their product. Is it out of the realm of reality that we might someday include a tasting room in our sugarhouses where potential customers could sample the various grades of syrup and other value added products? Think about it, this could add a whole new dimension to the way we market maple syrup.
If you want to learn more about how you can use the new grading system to improve your marketing and your production practices I will be teaching a 4 hour workshop at the Lake Erie Maple Expo on Friday November 11th in Albion Pa. For more information on the workshop contact www.pamaple.org
Les Ober Geauga Co. OSU Extension
Every once and awhile it is good to go back and visit and old post with a good message here is one from 2013 with a few additions.
Maple syrup is often referred to as “liquid gold”. The increased demand for maple syrup and the escalating value of this year’s crop, has added new meaning to this old adage. Once the season is over you need to use a little TLC when it comes to storing maple syrup so it will maintain its quality and value. If you have not sold all of this year’s maple syrup and have some left in the sugarhouse or in a tool shed you need to watch the inside temperatures of those buildings. With all of the recent hot weather syrup stored in outside non- insulated structures can elevate in temperatures quickly and spoilage can occur. You may have thought that you covered the entire basis by packing the syrup hot in a sealed container. Maybe not!
Let’s look at how syrup is packed and stored. Most syrup is stored in stainless steel barrels that were packed in February and March. The syrup went in to barrels hot and was sealed. A thirty gallon drum is a hard vessel to pack there is always room for air. They very seldom are packed without a small amount of air space. The drums then cool to the temperature of the time of the year. Eventually over time the syrup inside the drums takes on the same temperature as the outside temperature. Steel transfers heat and cold well. The syrup on the inside of the barrel will remain cold for a long period of time due to its viscosity and mass. The steel in the outside drum will heat up quickly when outside ambient temperature gets above 80 and stays warm. The result is the buildup of condensation between the warm steel and the cool syrup on the inside. When this moisture gets into the air space molds can form. This is the same thing that happens to jugs when they are not heated to 185 degrees F. If the product is not above 66 brix the syrup can even ferment. The same is true for drums they should be packed hot and the seal should not be broken until you can the product. The worst culprit when it comes to spoiled syrup is a drum that was partially filled and then topped off with some hot syrup. This scenario and the spoilage that often comes with it can be avoided by repacking that drum at between 150 and 180 degrees Fahrenheit. It is always best to completely fill a drum with hot syrup right off the filter press, seal it and store it.
The best solution for long term storage is to build a cool room. You notice I did said cool, not cold. A walk in cooler would be the best case scenario but most producers cannot afford such a luxury. Take a small space big enough to hold several drums of syrup. This could be a closet or small room in a building. Insulate the room and stick a window air conditioning unit through the wall. When temperature gets above 80 deg. F for any length of time, fire up the air conditioner and brings the room to just below 70 deg. F. At that temperature the syrup will stays relatively cool in the barrels. It always seems to be colder than the outside temperature. You only have to get the syrup through the hot months, once the daytime temperatures cool off you are out of the woods. Another trick is to rotate the drum occasionally this moves the syrup around inside the drum. This should dissipate any moisture that forms on the metal wall of the drum thus reducing the chance of spoilage if the drum was packed correctly to begin with.
Geauga County OSU Extension
The season has come to an end and now you are faced with the arduous task of cleaning up you maple operation. Where do you start and what do you use? For most of the equipment the answer is simple lots of hot water and elbow grease. A good place to start is with the tanks that hold both sap and syrup. Most are stainless steel and area easy to clean with a high pressure washer. Plastic totes and poly tanks have become popular because they are relatively inexpensive but they are harder to clean. We found that a tank washing tip that will fit on your high pressure washer is a valuable tool. This tool allows you to spray to the side and get into areas that you cannot get into with a standard spray tip. We have also found that you do not want to let plastic totes sit around because the bacteria will build quickly. Clean them immediately. Plastic totes, while affordable, will only last about two or three seasons before the plastic is so contaminated with bacterial spores that you have to discard the bottle and replace it. If you keep poly tanks cleaned down they will last for years. However, if you can afford stainless steel tanks they are the way to go.
The evaporator needs to be sugared off and flushed out as soon as possible. I often flush down the pans with clean water and then refill them with permeate from the RO and let them soak. If permeate e is not available use water. I will drain and refill the pans with clean f water and then add the proper amount of pan cleaner and follow the directions on the label. Once the pan cleaner has done the job I will drain the pans and use a high pressure washer to finish off the job. If I do this process correctly I will end up with pans that look like new. Make sure all of your float boxes are clean and the gaskets are replaced if needed. Soak your auto draw off temperature probe and your hydrometer in a 5% vinegar solution to remove all of film. The thermocouple in the auto draw off probe work best when there is no niter on the probe. Make sure your filter press is cleaned thoroughly and the parts are lubricated with a food grade lubricant. One thing I always do is remove all of the extra filters from the sugarhouse and take them into you house and put them in a place that is dry and rodent free. If you use a filter tank make sure the filters are cleaned and dried thoroughly. If moisture is present they will mold. If they do throw them out and start next year with a new one. Never ring out an Orlon filter, your will break down the fabric causing it to filter poorly.
Ro’s need to be soap washed and thoroughly rinsed immediately after the last time you use them. Make sure all of the permeate is drained out. Once you break down the RO make sure to return your membranes to the storage vessels with a cup of permeate in each one. Once you have everything clean I take the membranes back to my dealer to be sent in for cleaning and testing. There is nothing worse than starting a season with a bad membrane that is passing sugar. Make sure your high pressure pump and your feed pump are free and fully drained. . Inspect the membrane housings get them as dry as possible. Many times with the recirculating motors and pumps on the bottom of the membrane towers dampness can cause the pump shafts to seize and seals to deteriorate.The evaporator and the Ro require the use of chemicals that are incompatible. One is phosphoric acid and the other is a basic soap. Keep them separate and out of the reach of children. Be careful when you mix pan cleaner follow the directions on the label.
The most controversial area when it comes to cleaning is the tubing system. Everybody has their own way of dealing with the miles of tubing stretching through the woods. Over the years I cleaned tubing just about every way possible. We have sucked water, pumped water and air, water, air and tubing cleaner, and just plain no cleaning at all. The water and air worked well until we tried to pump up to steep a grade and had a blowout that had enough force to launch a satellite. Sucking water through the lines, left a lot of liquid in the lines that eventually turned to green snot. We have now hit on a method that seems to work. We pull taps with the vacuum on. When we pull the tap we cut off the old spout and use a line plug developed by the Stars Company from Quebec. This seals the drop line and maintains the vacuum on the system. If done properly the sap in the lateral line will not suck back into the drop line. We also use a paint marker to mark the old tap hole. This way we will not put next seasons tap on top of an old tap. Once all of the taps are out we back flush the mainlines with clean water. Now we will close all of the main lines, then go to end of each lateral opening them up long enough to pull air through the lines and keeps vacuum on the system. It also removes 80% of the liquid out of the laterals and the mains. At this point we open the ends of the main line and let air in with the vacuum on. Once the vacuum drops to zero shut off the pump. At some point next fall we will go through and put on new spouts and let the lines air out completely. This system seems excessive but it does work. We had a little green sap at the start of the season but nothing we could not filter out. This could have been avoided by flushing the system in the fall. Here is a word of caution when it comes to using tubing cleaners. They have to be completely flushed from the lines at some point before the next season. Never use Isopropyl alcohol it is illegal in the United States. The Proctor Research Center has a good a fact sheet on this subject and it is worth reading. Also be aware some cleaners attract Mr. Bushy Tail and his friends, this is never a good thing for tubing operators.
Once you have your system cleaned bring in all of the releasers and clean and sanitize them thoroughly. They are made of PVC Plastic that makes a good home for bacteria. Go over the mechanism and use lubricant provided by the manufacture and lubricate all of the moving parts. The last thing is caring for all of your vacuum pumps and transfer pumps. Change the oil or drain out the water on liquid ring pumps. On the new rotary claw pumps change the oil and fog the pump with a pump oil. You need to make sure rust does not build up. Same is true for Rotary Vane pumps which are more maintenance free but putting some oil on the vanes never hurts. All gasoline motors should be drained and the gasoline replaced with Seafoam or a similar product. Never leave gas with ethanol in the tank. Drain the crank case oil and replace it with fresh motor oil and you are ready to go for next season. Make sure you transfer pumps are drained and stored in a place that does not freeze.
Ohio State University Extension
This post is in response to the article on maple syrup quality written by Dr. Michael Farrell in the last edition of the Maple News. First let me say that the article was not only excellent but very timely. The article addresses an issue that all of us producing maple syrup need to look at as we start a new seasons production. What I hope to do is highlight some of the areas in the production process where quality can be compromised. These are often identified through off flavors. The University of Vermont and the Vermont Ministry of Agriculture have given us an excellent tool for identifying the sources of off flavors in maple, “The Map of Maple; Off –Flavors”. This was also published in the last edition and is also available from the IMSI publications
After producing maple syrup for over 40 years and teaching seminars on maple syrup production for close to 20 years I have made, and have seen others make, most of the common mistakes that lead to off flavors and poor quality. In this article I will go over some, but certainly not all, of the factors that lead to poor quality. Many of which can be controlled by the producers with proper best management practices. The map of Maple: Off Flavors identifies 5 primary areas where off flavors occur; Mother Nature, defoamer, processing, chemicals and others. I want to address each of these, not in order but how they would occur from the start of the season to the end.
When you start out the season you need to be aware of several problem areas that can lead to off- flavors. Most stems from equipment maintenance after the previous season and going into the new season. When producers and hobbyist ask how I should clean up my equipment, my response is with a lot of water and elbow grease. Anytime we use chemicals to clean equipment we run the risk of leaving behind residues that can compromise flavor. If we use chemicals on our pans to clean them at the end of the season the chemical residue needs to be thoroughly cleaned out. If we store filters make sure there is no mold on those filters when they come out of storage. If you have mold on your filters, throw them out. Never use detergents to clean filters it will alter the flavor. Finally make sure you store your chemicals in a secure place away from the process of making syrup to avoid unintended contamination of your product. Finally if you use a tubing cleaner make sure it is flushed from the system. If you suspect some cleaner may be left in the lines then let part of the first run go to the ground. Most of the above are common sense but they need to be mentioned.
Probably the biggest culprit when it comes to off-flavor is processing. This is where the majority of the mistakes are made that result in off flavors. When we grade syrup we look at 4 primary areas density, color, clarity, and flavor. Even though each is judged separately they are actually all interrelated. Density affects syrup quality in several ways; first syrup must be 66 brix to meet USDA standards and if it is below 66 brix it can ferment and cause an off flavor. Syrup above 67 brix normally does not have an off flavor but the higher density can cause crystallization in the bottom of the container and loss of revenue to the producer. As syrup moves across the front pan the density changes rapidly and so does the color. Density changes occur with the rapid removal of water increasing the sugar concentration. Color changes occur as the sugar molecules change due to the introduction of heat. These changes happen very quickly and need to be monitored closely. Anything that interferes with flow of sap through the evaporator can cause the syrup to get darker and possibly cause an off flavor. Many feel that density is the most critical part of the process and at times reaching the proper density can be very illusive. Improper density management can lead to two off flavors that are very common in syrup; fermented and scorched. It can also lead to an unwanted change in color. The additional boiling time can also affect flavor causing an unnatural taste that is not representative of the grade you are processing.
We use three tools to measure density, the hydrometer, the thermometer and the refractometer. All sugarmakers use a hydrometer. Hydrometers should be inspected or checked for possible problems and replaced if suspect. Often the paper with the scale printed on it can slip resulting in the wrong brix reading. The hydrometer can become coated with film resulting in an inaccurate reading. A good hydrometer will give you an accurate reading only if it is used at the right temperature. Temperatures below that require consulting a chart to get the right brix reading for a specific temperature. Maple syrup boils at 7 degrees above the boiling point of water or 219 degrees. Many producers use a thermometer to determine the draw off point. The only problem is that that the 219 reading is only accurate if the barometer is at 29.9 hg barometric pressure. A thermometer needs to be recalibrated every time the barometric pressure rise or falls. This makes a thermometers reliability somewhat suspect. However, syrup temperature is vital when it comes to setting an automatic draw off. The final tool is what many consider the judge and the jury of maple syrup density, the refractometer. What many producers do not realize is that, for a refractometer to work properly, it needs to read a product that is finished and one that is stable in temperature. This was pointed out the other day, when I had a conversation with Robert Crooks of Marcland Instruments. For a refractometer to work properly it has to be able to refract light coming through the sample it can only do that accurately if the sample in the instrument is a clear finished sample. Taking a sample of cloudy unfiltered syrup can lead to an inaccurate reading. The temperature of the product also affects the light refraction. Even though the refractometer is built to automatically compensate for temperature that temperature needs to be stable. If you leave freshly drawn off syrup set in a container it will continue to evaporate water until it cools down. Think of what happens to a roast when you pull it from the oven, it continues to cook. This is why it is recommended that you cover a container with hot unfiltered syrup to stop the loss of moisture. If you use a refractometer to set the draw off, take the syrup and run it through the filter and collect a sample allowing it to sit for 15 minutes then take your refractometer reading. This will give you the most accurate reading from your refractometer.
If you use a conventional auto draw-off, be aware that it takes time to complete the draw off process. This means that syrup will be drawn off over a range of temperatures. Therefore set the draw off to actuate slightly below the desired temperature and it will finish slightly above. Using a hydrometer is the best way to set your draw off. However, make sure you are reading the hydrometer at the recommended syrup temperature. You can use a refractometer but it has to be used on a finished temperature stable product. This process may take more time than you have to make a correction on the draw-off.
As sap moves across the evaporator temperature gradient sets up. Ninety percent of the water is removed by the time the sap reaches the middle of the front pan. Syrup needs to move from the middle of the syrup pan to the outlet relatively fast. Any interruption with this process that interferes with the temperature gradient and holds the syrup on the pan longer will result in syrup that can be darker and denser than desired. One common mistake is to allow the pans to cool during the firing process. Anytime you cool off the pans the temperature of the sap drops and this causes the boiling temperature to drop resulting in the sap on one side of the gradient to mix with sap on the other gradient. You need to keep a constant heat level on the front pan at all times. This is more critical in a wood fired evaporator.
The other problem is foam control. Excessive foam in the back pan can cause problems with you float and may interfere will your ability to control the level of the sap in the evaporator. If this happens you will need to use a defoamer to control the problem. When using defoamer, the only place the defoamer should be added is at the point where sap enters the rear pan and occasionally a couple of drops if needed, at the draw-off if foam builds up as you are drawing off. This should be done at regular intervals placing the prescribed number of drops (2 drop per foot of width) where the sap enters the evaporator. Never spray defoamer across the front pan to control foam. Using defoamer in this manner will impede the boil and break down the gradient. This can lead to the dreaded big batch. If the front pan is foaming excessively, then the foam is not being properly controlled in the back pan, correct the problem back there. Use only small amounts of defoamer, excessive use can result in an off flavor. Organic producers must use safflower or canola oils which are very poor defoamers. Be careful, using an excessive amount of these products can result in an off flavor.
The other problem that can cause scorching in an evaporator is to allow niter to buildup. When niter buildup it will insulates the bottom of the pan from the liquid creating a potential hot spot which can result in a scorched spot on the pan. You need to keep liquid in contact with the pan at all times. Always keep your pans as niter free as possible by rotating sides or using a clean set of pans. Using a good syrup filtering system to remove niter is vital if you want to produce syrup that meets the clarity standard. You should be able to read newspaper print through a sample bottle of syrup that has been properly filtered. Cloudy syrup with a lot of niter can produce an off-flavor. Remember every time you heat your syrup to a boil more niter will precipitate out and it will need to be re-filtered. That is why you do not want to bring your syrup to a boil when canning. 185 degrees Fahrenheit is the required temperature for canning.
As maple producers we fight the growth of bacteria through our entire system. When bacteria colonies multiply within sap they convert sucrose sugar molecules to Glucose and other invert sugar molecules. This increase in invert sugar, when exposed to heat will cause a darker product. This is most prevalent at the end of the season when the bacterial content of sap is at its highest. Bacteria can affect the entire process of making syrup from the tubing system right through canning. Because sap has a sugar content it is a perfect media for bacterial growth. It goes without saying you can never be too clean when it comes to making syrup. Sap needs to be collected in clean equipment, it need to be kept cool and processed quickly. At the beginning of the season if we start with a properly sanitized system we have few problems with bacteria but as the season progresses the problems increase. Maple Producers need to know when to end the season. Producing syrup late in the season when the trees are near budding and the sap is out of condition has little value to you or the industry. Syrup also needs to be packaged correctly to control bacterial growth in container that can lead to spoilage. That is why we always pack plastic jugs at 185 degrees. This prevents condensation which can supply an environment for bacterial growth in the container.
As you can see there are many areas within the process of making syrup the sugarmaker can have an impact on the quality of the product that is producing. The is attention to detail from equipment sanitation to efficiency of processing is what separates many producers when it comes to product quality. Making the highest quality product possible should be your goal, you reputation as a maple producer depends on it.
Ohio State University Extension
When you bring up the subject of vacuum, one of the first questions producers ask is what size vacuum pump will I need to run my system? They also ask if the old rotary vane pump their grandfather abandon in the barn is good enough? The question I ask them is; what vacuum level do you want to run at today and into the future. As I stated in Part I there are two way to measure vacuum pump performance, inches of mercury and CFM. Inches of Mercury measure the negative pressure produced when air leaves the line. For example if 50% of the air is removed then the inches of mercury should be 15. At 25 inches of mercury approximately 85% of the air has been removes from the lines. CFM on the other hand measures the amount of air being evacuated from the lines measure in cubic feet per minute. Pumps are rated (CFM) on their ability to remove air and this largely determines the size of the pump. Two other factors come into play when comparing vacuum pumps. One is the horsepower rating. As the air is removed from an enclosed area the molecules of air in that air become very sparse. The pump has to work harder as the air becomes thinner. The pump also has to overcome the force of the negative pressure inside that area. This requires more horsepower. A larger CFM rating does this faster but requires more Hp. The other factor is pump speed. If you turn a pump faster your will move more air and will increase the capacity. However, over speeding a pump can cause excessive wear on the pump. To answer the second question first, Grandpas pump is not designed to produce anything over 15 inches of vacuum and that is not high vacuum. Most of the liquid ring, flood vacuum rotary claw and new age rotary vane pumps are designed to run at vacuum levels up to 29 inches. Remember all of the pump ratings and their ability to increase vacuum level are done at the factory removing air from a sealed vessel. From this information a performance curve is developed. What makes this whole process more confusing is that many maple equipment companies are now listing there pump sizes by motor horsepower instead by CFM capacity. As pointed out motor Hp is only one factor determining pump capacity. When questioned about CFM, one dealer told me his pump will develop 11 cfm at 29 inches of vacuum. This has to be a specification taken off of a performance curve taken at the factory. The question I have how likely is that pump will ever reach 29 in of vacuum in a maple system? The fairest comparison should be made when the CFM is measured on a pump being run at 15 inches of vacuum. Otherwise unless you have performance curve data in hand for every pump you are considering how you can make a fair comparison. Will the pump be able to deliver 29 inches in the woods at a higher elevation, hooked to thousands of feet of line that is anything but leak free?
Are the dealers wrong when they tell you that your pump will produce 29 inches vacuum? The answer that question is yes and no. As stated most pumps are capable and have been tested to deliver 29 inches of vacuum. This is clearly shown on the pump performance curve. However because the performance curve is read at the barometric pressure at sea level an adjustment for elevation above sea level needs to be made. For every 1000 feet of elevation you lose 1 inch of vacuum, this means the highest vacuum level achievable at an altitude of 2000 feet is around 28 inches depending on the barometric reading on any given day. So what is going on when a producer tells you that his pump gauge mounted somewhere nears the inlet of you pump is reading 28 inch of vacuum but out in the woods it is 18 in. or less? Is that wrong? The answer to the second question is no. Because of line diameter is restricting the flow (Line Loss), the vacuum pump has the ability remove all of the air from the system within a short distance of the pump inlet. This phenomenon occurs because the pump can pull air out faster than the line can deliver it, thus creating a small area of high vacuum close to the pump. The gauge at the pump measures only the vacuum in that area. This is graphically displayed in the line loss charts used in the Cornell New York State Tubing and vacuum system notebook. A 60 CFM pump set at 15 hg hooked to a 3 “ line can maintain over 40 CFM out to 5000 feet. That same pump hooked to ¾ inch line is incapable of delivering 15 in. of vacuum at 25 feet. This is covered in a previous post; April 24, 2013 How Can I Get More Vacuum Where I Need it? The pump is only one part of the total system. If the line diameter is too small it will reduce the capacity of the pump to remove air. The reality is that the only vacuum reading that counts is the reading that is taken out in the woods at the last tap.
How do you determine the CFM capacity of the pump that will best fit in your operation? The NY State Tubing Vacuum Notebook (NSTVN) written at Cornell University by State Maple Specialist Steve Childs states that to go from 15 inches to 18 inches of vacuum of vacuum you need to increase the CFM capacity of your system by 50%. You start with the number of taps you have on the system. Let’s say you have 3000 taps. You know that for every 100 taps you need 1 CFM to keep up with the air and gases coming into the system primarily from the trees. This means that it would take a least a 30 CFM pump to remove the air that is coming into the system from the outside. The vacuum level under these conditions would be somewhere around 12 Hg. The NSVTN states that for every 1 in of vacuum you will lose 10% of the capacity of the pump. In order to increase that vacuum level to 18 in or beyond you would need to increase the pump size by at least 50 %. That would mean that you would need a 45 CFM pump. This is only 18 inches of vacuum and you want to produce a high vacuum rate of at least 25 inches. This is based on research done at UVM Proctor Research Center you need to have at least 25 in of vacuum in the lines to get near optimum sap production. However to get to 25 in vacuum you would need to add 7 more inches of vacuum. Starting with a 45 CFM pump running at 18 in of vacuum, using the 10% loss for every 1hg gain you would end up with only 13.5 CFM (4.5 X 7 = 31.5 – 45 = 13.5 CFM). If you go to 75 CFM pump it translates 22.5 CFM (7.5 X 7 = 52.5 – 75 = 22.5), which falls 7.5 CFM short. A 100 CFM pump translates to 30 CFM (10 X 7 = 70 – 100= 30), enough to run the 3000 tap woods at 25 in of vacuum. Again all pumps are not created equal motor size and pump revolution speed come into play. These are just guidelines, some systems are easier to operate than other and it depends on well you manage your system for leaks.
Now let’s look at the yield side, again based on research done at UVM Proctor Research Center. In their study determining the yield up to 25 in of vacuum was their goal. The study shows that sap yield doubles when vacuum is taken from 0 to 15 in. From 0 to 15 in. there was a 8 gal per tap increase, from 15 to 20 in. there was a 3 gal increase and from 20 to 25 in. a 2.5 gallon increase. At 25 in. vacuum you have added 14 gallons of sap per tap. However, at 20 in of vacuum you have added 11 gallons of sap.. So what would happen if you settled for working at a lower vacuum level? If you backed down to 22inches of vacuum a 45 CFM pump would deliver 27 CFM just short of the amount needed. Going up to a 60 CFM pump would deliver 36 CFM, adequate to run the woods with some reserve. You would raise your production by 12 gallons per tap per season. That is 80% of your original goal of 14 gallons per tap.
You have now made all of the calculations and are beginning to understand the logic and principal behind setting up a vacuum tubing system. The one thing we did not mention was the importance of reserve vacuum. You also need to factor in the vacuum that is needed to run a manual releaser (at least 5 CFM) and anything else like lifts and vacuum piston pumps. All of these eat up CFM. You do not want to be maxed out on CFM capacity when Mr. Bushy Tail shows up. Factor in another 3 – 5CFM in reserve vacuum and hope he does not bring his relatives. Your system need capacity to recover from leaks and other unforeseen problems and it need to do it as quick as possible. In my small world of maple production I am not comfortable with anything under 35CFM. Here’s why! Our home woods only have 400 taps, the requirement to run those taps is only 4 CFM but I have maxed out a 35 CFM pump. Here is how we did it. First we have long mainlines because the woods is spread out. Secondly most the lines drain to a low point that is totally inaccessible to sap pickup. We use a lift to bring the sap forward to the releaser. We then move the sap from the releaser tank to road via vacuum operated piston pump. No one in their right mind would have put tubing these woods but we did and it works. We maintain 25 inches at the releaser, 22 inches of vacuum at the lift and 18 to 20 inches at the end of the mainlines. I will replace that pump with a bigger one someday but in the meantime we are constantly looking for new innovative ways to conserver vacuum and utilize what we have in the best way possible. Just like everyone else we are spending countless hours looking for what Mr. Bushy Tail and his friends have done to our tubing. I cannot over emphasize the importance maintaining your system. The most important time you will invest in you maple syrup operation will be the time you spend in the woods managing your tubing system.
Footnote: Many producers are successfully rnning their vacuum systems over 25hg. They are successful because their system is properly designed and maintained.
The variety of vacuum pumps on todays market is very extensive. Although vacuum has become a mainstay in maple production our utilization of vacuum pumps and equipment is very small compared to their use in the industrialized world. Maple production is just on the tip of the iceberg when it comes to vacuum utilization. Even though vacuum is used extensively in the maple industry we have only been at it a very short time. For this reason there is a lot of misunderstanding about the laws of physics (Quantium Mechanics) that govern the science of vacuum. The online encyclopedia Wikipedia definesthe word vacuum as “void of matter”. In fact it stems from the latin word vacuus which means vacant. The study of vacuum goes back to the Greek Age and the time of Aristotle. Several basic scientific principals apply when it comes to vacuum. Due to pressure exerted by the earth’s atmosphere (15 lbs per sq. in.) you can only achieve a maximum vacuum level of 29.92 inches of mercury. You actually can only achieve a vacuum level equal to the barometric pressure on any given day at any given location. Barometric pressure changes with the elevation above sea level. Another principal is how we measure vacuum. The level of vacuum is a negative measure (because you are creating a negative pressure inside of a vessel) and is read in inches of Mercury. The rate of air being removed from a vessel by a vacuum pump is measured in cubic feet per minute on an English measurement scale.
Even though it has become the Holy Grail, in the maple industry, the term “High Vacuum” is largely misunderstood. High Vacuum or perfect vacuum exists only at 29.92 in. Hg. This is the highest level of vacuum achievable in our atmosphere and occurs only when every molecule of matter is removed from a vessel. This is extremely hard to achieve because once all of the air is removed there are still other gases that qualify as matter and are very hard to remove. In fact the closest thing to a perfect vacuum only exists in outer space and we are not producing syrup on the moon. Wikipedia states “There are three levels of vacuum achievable with modern vacuum pumps. Low vacuum (vacuum cleaners), Medium Vacuum (achieved with a single pump) and High Vacuum (achieved with multi-staged pumps and measured with an ion- gauge).” As you can see the vacuum we use falls in a range of somewhere between low and medium. Obviously the average maple producer does not live in the scientific world of vacuum, nor does he need to. The reality is that we are not dealing with a closed vessel but rather miles of tubing where the introduction of air occurs at every tap, fitting and squirrel chew. The range that most maple producers should be comfortable with is around 20 in. to 27 in. of vacuum depending on their system and the pump they are using. The reason being is that, this is that all vacuum pumps are not created equal and vary greatly in their ability to produce vacuum. Now this is where the discussion and the debate begin. As I have stated in an earlier post (March 25, 2013 Is it The Pump or The Mainline Size That is Effecting the Performance of Your Tubing System?) the producer must consider the entire system before he decides on the type and size of vacuum pump to use. Even though we are increasing the volumn of sap being produced by increasing the level vacuum closer to 29.92 we need to be more concerned about the ability of the whole system to remove air from the system efficently. Rather than concentrating on achieveing the maximum depth of vacuum we should be paying closer attention to the systems ability to overcome leakage and everyday wear and tear.
There is a wide variety of vacuum pumps that can be used to apply vacuum to a maple tubing system. In fact with the use of 3/16 tubing (based on the research of Tim Wilmot at the Proctor Maple Research Center) you may not even need a vacuum pump to achieve your vacuum goal. Most of the pumps used in the maple industry are adapted from some other type of use. The first pumps came from the dairy industry and were used to milk cows. These were rotary vane pumps that were designed to produce around 16 inches of vacuum. The vacuum was produced as the air trapped between the vanes held in an offset rotor was expelled to the outside via the exhaust. As the vacuum level increases heat is builds as a result the system needs some kind of lubrication to absorb the heat. The pump is lubricated with oil that was contained in an oil reservoir. Once you went above 16 inches the strain on the pump produced more heat that it was designed for. For that reason oil coolers and oil-reclaimers were used to make them more efficient. Bearings need to be lubricated with a precise amount of oil to maintain function. When running above 20 in hg, if any of the above are neglected you are headed for a Chernobyl type melt down. There are commercial rotary vane pumps (running a flood vacuum) on the market that are capable of achieving up to 27inches of vacuum. One of the most popular pumps being used is the liquid ring pump. The liquid ring pump uses an impeller running in a ring of liquid producing close to 29 inches of vacuum. As the air is drawn in it becomes trapped in a compression chamber that is formed between the impeller veins and the liquid. The air is expelled to the outside as the liquid (oil or water) is recycled. These pumps achieve as close to 29 inches of vacuum as any pump on the market. The down side of this type of pump is that a water source is needed and that source needs to be kept above freezing. If oil is used then there are environmental considerations.
One of the most recent pumps to come on the maple scene is the rotary claw pump. The rotary claw will produce 27 inches of vacuum, just under a liquid ring. This is a pump that is designed for continuous duty and one that requires minimal maintenance during the season. The claw runs at a very close tolerance to the chamber and traps air in-between the claws and the chamber and expels it to the outside. A small amount of oil is used lubrication. The downside is that these pumps are very expensive. They are designed to be run year round. Long layover periods may allow the pump to develop a rust layer inside to the pump resulting in excessive air. Because they run at a very close tolerance this may lead to early breakdowns. If you buy a rotary claw you need to fog the pump with anti-oxidation oil in the off season to prevent premature wear.
The last pump is the new age rotary vane pumps that are designed to run continuously and to produce a vacuum of 29 inches. This appears to be a very efficient pump. These pumps are similar in design to the older rotary vane pumps but have very close tolerances. They lubricate with oil but total requirement is minimal. So let’s rate the pumps on their ability to produce high vacuum from top to bottom. At the top is the liquid ring and the new age rotary vane with the edge going to the liquid ring especially one of the two stage models on the market at this time. These pumps will consistently reach 27 to 29 inches of vacuum. Not far behind is the rotary claw which will produce 27 to 28 inches of vacuum. Next is the improved rotary vane with a flood system at 27 inches. At the bottom is bossy’s favorite the old style rotary vain used in milking systems. She liked it because it produced no more than 16 inches of vacuum. Any more and she would send it across the room with one swift kick. No matter what you use you will get more sap from you trees. Collecting maple sap with a vacuum system not only saves time and labor but the vacuum will increase your sap yield by up to between 50 % and 150%. In the next post I will cover things you need to consider before you hook your pump into the system.
Geauga Co. OSU Extension
Expansion in the maple syrup producing regions has been in high gear over the last several years. In New England and New York there is little doubt on how and where expansion will occur. In both areas you have mountainsides with 1000’s of maple trees. Much of this land is owned and leased by the government or large private companies. Obtain the operating capital; lease the land run the pipeline down the mountainside to the sugarhouse and you are in business. Ok I realize it is not that simple but it is a lot easier than expanding in Ohio. We have fewer trees, in smaller concentrations, which are spread across the state. There is also the issue of convincing landowners to lease their trees. This can be very difficult to say the least.
Let’s look at the process of leasing trees for maple syrup production. The majority of trees in Ohio are privately owned. Most of the government owned woodland is located in SE Ohio in areas that have never been considered prime maple producing area. Sixty percent of the maple production in Ohio is done in the northeast quadrant of the state. This is an area that has seen increased pressure from urban development and the price of that land reflects developmental value not agricultural value. This often makes it unaffordable for someone to buy a woodlot for maple production. To compound the problem much of this land is owned by “Baby Boomers” who have passed away or are now ready to leave Ohio and transfer ownership to a sibling or a third party. Often the cost of ownership (land tax) or the cost of settling an estate will determine what will happen to the estate. Many times the family is forced to liquidate assets such as timber to offset these expenses. As a result many of our prime sugar bushes have been cut down and lost in the process. Unfortunately in times of duress families do not receive the full market value of the timber as a result of a quick sale to take care of financial obligations. This often compounds the agony of estate settlement. They also do not take the time to explore all of the options for utilizing their woodlot.
Today a profitable maple operation relies heavily on technology to be successful and that includes a vacuum tubing system. Installing a tubing system requires a long term (7 to 10 years) lease. Many landowners are hesitant about entering into this type of agreement for a variety of reasons. One of the primary reasons is that the owner does not want to be bound to a binding contract if something would happen and he had to sell the property. Even if a sale is not forthcoming coming many owners are uncertain about how their actions might impact the next generation. This needs to be a consideration when designing a lease. There need to be an emergency escape clause that protects the rights of both parties. One ways of softening this objection is for the owner to get a substantial financial return for leasing the woods. Consider the fact that an average lease on cropland now starts at $100.00 per acre (this is high for some areas and low for others). This means that woods with 80 taps, renting for $1.00 per tap would be equivalent to many cropland leases. This also this also demonstrates why maple lease rates need to start at $1.00 per tap to keep a woodlot lease comparable to a cropland lease. The only way to determine a rental rate is to accurately estimate the number of taps per acre.
Since the millennium it has become increasingly hard to find an unused sugarbush in prime condition in Ohio. Often times a maple producer hears about a stand of timber that might be available for taping and he decides to look at it and it falls way short of his expectations. I can tell you from experience that I have walked more than one woodlot where the owner was sure he enough trees to make syrup. Yes he did have maple trees but not nearly enough to be economically feasible for maple production. The reason for this is that many of the woodlots are 2nd and 3rd growth timber containing large numbers of smaller trees. Because these woods containing trees that are not ready for a timber harvest due to their size the owner is years away from harvest and potential financial gain. This makes maple syrup production a very viable option that can be attractive to the owner because he can get an immediate financial return from his woodlot. On the other side, the producer is looking at single tap trees and trees that may not immediately be big enough to tap for several years. The long term goal of the producer should be to convince the woodlot owner that maple syrup production is a worthwhile use of his resource resulting in the continuation of the lease over time. If these were large mature maples it would be very difficult to make a case that he could make more money by leasing for maple syrup production. In this case the only chance you have is to increase the rental rate and make a case for selective harvest that will preserve some of the larger trees. In both cases the axiom; “The best way to preserve sugarbush is to tap a sugarbush” , applies.
What are the criteria that I go by to determine the feasibility of transforming a woodlot into a sugarbush? Start with a good layout plan. The producer wants to avoid excessively long mainlines going to trees scattered over a wide area. Slope is important but there are ways to work around slope issues. The most common problem with slope is that the woods often slope away from the collection point. This problem is usually solved with the installation of auxiliary tanks, long pump lines and a transfer pump big enough to handle the volume of sap produced. All of this adds to the cost of installing the tubing. The best way to determine layout is to use a GIS map with contours to find high and low points. If you are lucky enough to find a woodlot where to dominant tree is the sugar maple of tapable size and those trees are dispersed evenly across the landscape, you have found a real Jewel. However, most time you end up with sugar maples mixed in with red maple and other hardwood species. A good sugarbush will average 80 taps per acre. Anything below 50 taps per acre is considered marginal. If it is in a woods that has been previously harvested then size of the tree (smaller than 10 inch cum.) becomes an issue. You need to use an angle gauge or prism to determine size at a distance. For closer examination a 32 inch circumference chain will equate to 10 inch diameter tree. The best way to determine tap numbers is to lay out a circle with a 26.4 inch radius from the center. Count all of the tapable trees in that circle and multiply that number by 20 to give you the number of taps in an acre. Example (in a circle with a 26.4 inch radius) 5 taps X 20 = 100 taps per acre. You want to do this randomly at multiple locations across the woods. Average all the results of those locations together to come up with an average number of taps per acre for the woodlot.
Now it is time to develop a management plan. A well-managed vacuum tubing system should produce ½ gallon of syrup per tap. At $50.00 per gallon that grosses you from $1250 up to $2000.00 per acre. That is a gross return, all of your production expenses including your labor needs to be deducted to give you a net return on you investment and your cost to produce a gallon of syrup. One of those costs is the initial cost of installing your tubing, spread over a 10 year period.. You need to know your cost of production before you can put together a lease offer.
What are the selling points of a good lease? A good lease agreement is built on the premise of Best Management Practices. This includes tree size determination, general tapping practices, access for the owner and operator, BMP responsibility, owner liability protection and finally rent per tap. All of these need to be adapted to the woodlot you are trying to rent. For example the owner depends on the woods as a source for firewood. He has to have access to the woods in the off season. You must lay out your system to allow access. This includes being able to disconnect certain mainlines and removing several laterals to allow for that access. He is also concerned about liability if you or one of your workers gets hurt in the woods while making syrup. You need to include him in your insurance liability policy as a co-insured, taking the risk off of him while you are on his property.
You now have a reasonable lease offer that works for you but will you be able to sell the idea to the landowner. You need to put yourself in the shoes of the landowner and ask yourself would you consider entering into this contract if it were offered to you. Hopefully the answer is yes but if it is not then you need to reassess the plan before moving on. What happens next will determine the success or failure of adding this woodlot to your operation. You now become a salesman trying to convince the owner that this is a good idea and both of you will benefit. If you have done your homework and you make your case honestly and sincerely you should be successful in expanding your maple syrup operation.