Category Archives: Maple Production
Geauga County OSU Extension
The production results from The USDA NASS Survey were published on June 9th. For Ohio the numbers were an improvement over 2016, but not by much. This year Ohio Produced 80,000 gallons, an improvement over the 70,000 gallons produced last year. Once again 75% of the producing states improved their production and for some it was a major improvement. New York and Maine each added close to 50,000 gallon to last year’s production. The nation’s leading producer of maple syrup is no surprise, Vermont. Vermont is in no danger of losing its crown; production was once again just under 2,000,000 gallons. Finishing out the top 5 were New York with 760,000 gallons, Maine with 709,000, Wisconsin with 200,000 and New Hampshire with 154,000 gallons. Ohio continues to slide in its ranking to a disappointing 9th place. However, Ohio producers did increase production over 2016 by 10,000 due to an early start. The earliest recorded start date in Ohio was January 1, 2017, 25 days earlier than 2016. The problem is that when you look at the average start date across the state it was February 11th. That was problem given the mild weather conditions we experienced in January. You also have to consider that the temperature reached 77degrees F at CLE on February 24th and the season ended early around March 16th. By comparison Vermont recorded their earliest start on January 1, their average starting date was February 24th and their average closing date was April 10th , that translate into 2 million gallons of syrup produced over a 3 month period. Both New York and Maine had similar scenarios.
There were not many changes in the weather pattern experienced in 2016. Weather, once again had a negative effect on production in the Buckeye State while the mild weather in the East boosted production in that region. Increasing tap numbers and warmer weather early in the season has allowed producers in that region to dramatically increase production. Climate change is definitely opening up opportunities to make syrup in the northern regions of states like Vermont, Maine and New Hampshire. Production is being expanded in regions that are at a higher elevation where traditional maple production was once hampered by steep slopes and short seasons. Now with the advent of vacuum and 3/16 tubing systems along with the trend toward early tapping, production has exploded in the form of huge 100,000 plus operations. Modern sugaring operations in the eastern states are not only big but they are efficient. The amount of Syrup per Tap in the big three has steadily increased and stayed around .300 gallons of syrup per tap. This has pushed the average syrup produced per tap in the United States to over .300 tap. This was an area where Ohio was once a leader but recently Ohio production has declined to .200 per tap. You can clearly blame, two poor production years in a row for this decline.
One final statistic that has shown a modest improvement over last year, but is still below 2015, is the number of taps recorded in the Buckeye State, showing only 400,000 taps in 2017. For anyone working closely with the Ohio maple industry this statistic is mind boggling given that expansion going on in sugar bushes across the state over the last 5 years. The only explanation for this is that a large portion of the syrup being produced in Ohio is going unreported. Another statistic that tends to cast suspicion on validity of Ohio’s maple production statistics is how Ohio producers choose to market their syrup. In 2015 44% of Ohio producers sold to the retail market. That number has dropped to 30% in 2016. At the same time the Bulk sale market share has gone from 32% in 2015 to 43% in 2016 ( note these numbers are always one year behind the current year). Look at the marketing trends of big three (VT, NY & Maine) you will see that in the areas of expansion and big production the largest percentage of their syrup is sold on the bulk market,46% in NY, 86% in Vt. and 93% in Maine. Now take a look at a state of Connecticut and you will see they sell over 50% retail. Makes you wonder how much syrup is actually being produced in Ohio and is being sold out the backdoor to eastern and western packers. If this true, it is sad, because the demand for maple syrup is on the increase in Ohio and the stores are flooded with Canadian and Eastern States syrup.
So what have we learned from the last several maple seasons and how can we improve our maple production? The one thing that is clear is that the last five years have not been normal seasons for producing maple syrup. 2017, 2016 and 2013 were all warmer than normal and if you wanted to maintain average production for your operation you had to start early to get the early runs. This was especially true in 2017. Even the Polar Vortex Years of 2014 and 2015 presented their challenges due to the extremely cold winters and late starts that we experienced. The fact is, when the weather is right make the move and tap the trees. In most cases you will never make up for production lost early in the season by trying to extend the season at the tail end. Another factor is syrup quality. It is much easier to make a quality product in the first half of the season rather than struggling to make quality syrup while battling warm weather and increased bacterial contamination at the end. Hopefully 2018 will be a banner year for Ohio Maple producers, we are long overdue for a good one.
Les Ober OSU Extension
There have multiple posts on the Ohio Maple Blog Facebook page concerning the weather and how it will affect the maple syrup season in Ohio. Let me say this at the onset, no one is able to predict the weather long range with a great degree of accuracy more than a few days out and this year has proven that. What I do know is that we are faced with up to 6 days of temperatures above 50 degrees. If that does happen it will be the first time in 80 years for the last week in February. It will also push our trees closer to bud break. Right now we have accumulated 20 growing degree days. A Red Maple could experience bud break at 44 growing degree days (Gdd). That means we have to accumulate 24 more days in Burton Ohio to break the buds on a Red Maple. It is possible that we will accumulate almost one third of those this upcoming week. That being said this will change as we move further south in the state. There are areas right now in the southern part of the state that may very well see first bud break on Red Maples and Silver Maples by the end of next week.
Buds coming out this time of year is very early even for southern Ohio. There are many factors that lead to what I will call premature budding of maple trees. Day time temperatures have the biggest influence on budding. Anything above 50 degrees is counted as a Gdd. However, the temperatures in a woodlot tend to be lower than at the street level. The trees on the street will bud faster than those in the woods. How much snow do you have? Right now we have 4 to 5 inches on the ground and that will keep the woods colder during the first part of the upcoming weekend due to convective cooling, especially at night. The bigger question is how much snow will show up in March? Snow is good not only to cool the trees but slow release moisture for sap flow. How much cloud cover do you have? Cloud cover keeps the warming sun rays away from the tree branches. It is those bright sunny days that move a tree closer to bud break. Northern Ohio has more cloud cover than southern Ohio especially close to Lake Erie.
What will tell the story is the forecast going into the first week of March? Right now it is calling for cold weather. I think the weather pattern that sets up after March first will determine the length of our season this year just as it did last year. Area north of Columbus will survive this warm spell but south of Columbus is questionable. The long range NOAA Weather forecast for Columbus north shows that we will trend below normal up until St. Patrick’s Day after that it will trend slightly above normal. In the Cincinnati area the trend will be to go above normal and will osculate close to the freezing during the night. Northeast Ohio once again appears to have the best chance of making syrup through the end of March due to fact that our average daily lows are in the high twenties throughout the month. If it freezes at night we will be ok.
The good news is that the early tappers have reached the halfway mark of a normal season. The run this weekend will be big one. If you have not tapped you had better get in the woods and get the job done and catch this run. Take what is given to you in the days ahead and be thankful for what you have produced so far. We are definitely in era of change in how and when we produce maple syrup. If this trend continues for one will plan on having everything ready to tap on New Years Days. If it sits for a month so be it but if the weather patterns are right the trees will get tapped. “Fool me once shame on you fool me twice shame on me”.
The Steam has finally cleared! What a January it has been, when it comes to making maple syrup. There had to be some kind of record set in Ohio for the amount of syrup produced in the first month of the year. Locally most of the bigger producers tapped and produced between 200 and 400 gallon of syrup. This was a personal best for most of them in the month of January. For many who tapped around the 12th of January it was the earliest they had ever tapped. Geauga Maple Company and Grossmans Sugarbush in Claridon Twp. Geauga County were both going early. Talking to Jason Grossman at the Ohio Maple Days he indicated that they had boiled 5 times prior to the winter meetings. Sugar Valley Farms in Middlefield, made right at 400 gallon as did the Gingerich Family Sugarbush in Burton Township. The Howel’s Family in Northwest Pa. also had a good early run and made a considerable amount of syrup. Reports were coming in all over New England on Facebook from early tappers with the same results. The easiest way to keep up on the season’s progress in Ohio and elsewhere is to go on the Ohio Maple Blog Facebook page. I will also keep a running summary of events on the 2017 Maple Progress Report.
On the 30th of January old man winter returned with an outbreak of winter weather in NE Ohio. Overnight we received 12 inches of Lake Effect. This will make tapping and working lines harder in this part of Ohio. It looks like a two week lockdown of cold weather with very little time above freezing. Looking at several weather sites, I do not see anything much above 32 or 34 degrees before February 15th. That forecast would parallel what NOAA Weather had predicted for the first half of February. Long Range forecasts predict this trend of below normal temps will continue on into March. This means cold weather up front but cooler weather as we move toward April. This is a good thing if the normal air temp is 45 to 50 degrees in Mid-March it means we will maintain conditions conducive to sap flow. Another good thing is that no day time/night time lows are predicted to be below zero. Tell you how this all works out when we get to the middle of March.
The other thing to consider for the early tappers is will your taps hold up over almost 3 months of exposure to the elements. Again this comes down to what kind of plan you had prior to early tapping. Did you use new taps, did you change out drops and taps or did you install check valves? Is your plan to keep the vacuum pumps running whenever the air temperature is above freezing. For many this is uncharted territory. Last year was similar with cold stretching almost into March and then the season abruptly ended on the 10t of March. Early tappers were really only in for a little over 6 weeks at the most. That would be the length of a normal season. In the east the season started a little later and ran well into April. For those that did tap early the reward was a near normal season in Ohio and a spectacular season in the East. Only time will tell the outcome. I think we stand to learn a lot about the new technology we are using.
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.
The word came back to Ohio; from producers attending the annual maple manufactures open houses that it was going to be a big year in New England for maple syrup production. Many of the big northern Vermont and New Hampshire producers were not present, they were boiling syrup. When the steam cleared and the last syrup was drawn off, Vermont produced a record 1.9 million gallons of syrup in one season. Let that sink in, it was only 10 years ago that we struggled to produce 2 million gallons in all of the United States and in 2016 the State of Vermont alone produced almost 2 million gallons beating their 2013 record crop of 1.48 million gallons. The United States produced 4.2 million gallons the amount of maple syrup recorded since the early 1900’s. The top 5 producing states included New York with 707,000 gallons, Maine 675,000 gallons, Wisconsin 235,000 gallons and New Hampshire with 169,000 gallons of pure maple syrup.
With all of that syrup produced in the United States you can only imagine what they did north of the boarder. Yes it was big, it was really big. The Canadian crop is projected at 13.5 million gallons. This would set a new record for Canadian maple syrup produced and because most of that syrup is produced in the Province of Quebec; they set a record as well. This is a monster crop and no one knows what affect it will have on the price of maple syrup especially the bulk price. You can rest assured that there will not be any shortage of pure maple syrup in the world for some time. What about Ohio, unfortunately we are not sharing in the record crop celebration.
Ohio Maple Producers knew it was going to be a disappointing year for maple syrup production and the USDA NASS report verified their worst fears. 2016 was a real bummer across the entire state. The total production for the state dropped from 115,000 gallons in 2015 to 70,000 gallons in 2016. The Yield per tap is general ly a good production indicator. Over the previous two seasons (2014 & 2015) the average amount of syrup produced per tap was 0.275 of a gallon of syrup produced per tap. In 2016 the production dropped to 0.189 of a gallon per tap. Normally Ohio will exceed most states in production per tap but this year’s production was on the verge of disaster. The sugar content of the sap (often near or below 1%) certainly did not help the overall per tap production of syrup.
Another statistic that was very puzzling was the total number of taps recorded for 2016. This year the number of taps put out in Ohio dropped from 450,000 to 370,000 taps. In the last 10 years the number of taps in Vermont and New York almost doubled Vermont is just shy of 5 million taps and NY is right at 2.5 million. What is going on in Ohio? Why are we in a statistical state of decline? A better question would be is there really a decline? Working with extension and the Ohio maple industry for the last 18 years I have witnessed an overall expansion of the industry. It has not been unusual to see the number of operations with over 3000 taps increasing every year. I know of several that are over 10,000 taps. We will never be in the same category as New York or Vermont but our maple industry is growing. However, when you look at the statistics we are not a growth industry we are an agricultural industry in decline.
The reality is that a large portion of the actual production of maple syrup in Ohio is not getting reported. There is an old saying that “if it is worth doing, it is worth doing well”. I believe that Ohio maple producers are doing a good job of producing syrup but for some reason they are reluctant to let the world know how good a job they are doing. Why is it important to report your crop? The world rewards those that achieve excellence. In the case of maple syrup production that reward comes in the form of consumer demand for your product and increased retail sales.
Les Ober Geauga Co. OSU Extension
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.