Category Archives: Taphole Sanitation

A Funny Thing Happened to My Sap on the Way to the Evaporator

The following article was written and published in The Maple News May edition. In the article I took  a look back at the 2017 maple season. In Ohio it was very different and in many ways very educational.

The 2017 syrup season saw Mother Nature throwing just about everything at Ohio maple producers. In years where everything seems to go as planned, and production is good, we tend to overlook what can happen when we have deal with extreme conditions.  2017 was a year of extremes; we were constantly exposed to either extended warm or cold weather. The season started early for many and never really got off the ground for others.  February 20th was the beginning of a warm spell that ended on February 24th with the temperature in Cleveland, Ohio reaching 77 degrees, breaking several records in the process. The first two weeks of March were cold with minimal sap flow; this was followed by a warm up that ended the season on March 27. After a year like 2017 many Ohio producers are still wondering what actually ended the season.

When sap comes from the tree, the sweet liquid is sterile. Once the sap is exposed to the environment colonies of bacteria begin to grow in the liquid. A 2003 research study done in Quebec, Canada by Legace, Pitre, Jacques and Roy isolated 32 different t isolate groups of bacteria found in maple sap. As producers we often think of bacterial growth as bad because many of these bacterial strains cause maple sap to spoil (Morselli and Whalen 1991 & 1996). The ironic fact is that not all bacteria are bad and several strains of bacteria and yeasts are needed to give maple syrup its unique flavor and color (Wilits and Underwood). This was reconfirmed in a 2011 study done in Quebec Canada by Filteau, Legace, Lapointe and Roy. The Maple syrup is almost 100% made up of the sugar known as Sucrose. When bacteria are introduced into the sweet sap solution fermentation occurs via hydrolysis that results in the breakdown of a small percentage of the sucrose into fructose and glucose. This is often referred to as the invert portion of the maple sugar complex. When heat is introduced, there is a thermal reaction (Millard Reaction) that causes the browning of the liquid during the boiling process. This gives maple syrup its signature amber color and unique flavor.  As the bacterial contamination increases the result is an intense darkening of the syrup and a pronounced strong flavor. With an overabundance of bacterial growth in the sap results in the formation of acids that can cause a sour smell and taste known as Sour Sap. If boiled into syrup, the syrup often becomes thick and stringy, forming Ropey Syrup.  The highest probability of this type of contamination usually occurs at the end of the season.   However, as many producers found out this year,   it can happen anytime during the season, when environmental conditions are right and bacterial growth is left uncontrolled.

As we reach the end of a season, one of the most often asked questions is; how can I tell when the season is over. During a normal season we have two completely different biological processes that often occur simultaneously at the end of the season.  This can be confusing to producers especially new producers.  The season ultimately comes to an end when the trees begin bud formation and leaf emergence. The presence of abnormal sour sap is often mistakenly associated with the budding process because in a normal season the onset of warm weather not only increases bacterial growth but is pushing the trees closer to the formation of buds.  The off flavor associated with budding is similar but distinctly different than Sour Sap. Buddy Syrup has a chocolate or tootsie roll like flavor and when boiled, the steam will take on an unforgettable pungent aroma. The easiest way to identify buddy syrup is to boil a pot of the suspected liquid on the stove and wait for the aroma. If the aroma shows up the season is over.

February 24th marked the end of the season for many Ohio producers despite the onset of cold weather in the first half of March. Those that tap predominantly Red Maple were justified in their decision based on the premature bloom of their trees. Others simply lost the battle to bacterial contamination. The producers with the best chances of extending the season past the freeze up were those using tubing systems that were run continuously 24/7, regardless of sap flow during the warmup. Continuous operation keeps the sap flowing away from the tap hole and it also has a cooling effect, as a result of air being transferred through the lines. In addition almost all were using some type of tap hole sanitation technology in the form of check valves or regular replacement of spouts and drops. The key word here is sanitation. Producing top quality syrup starts with a tubing system and equipment that is properly cleaned and stored at the end of the previous season.  It continues with constant sanitation of equipment throughout the maple production process.  A good example is replacing plastic sap storage tanks with easy to clean stainless steel tanks. Plastic tanks are one of the worst harbingers of bacteria because the plastic is porous and cannot be easily cleaned or sanitized. Many of the larger operations have now adopted new evaporator cleaning systems that clean not only the front pans but also the flue pan. This involves draining the back pan between runs and recirculating RO permeate water to remove niter and slow bacterial growth in the evaporator.  Cleaning your equipment immediately and processing your syrup as quick as possible is essential if you want to make a quality product throughout the season.

We can control sanitation and processing but the trees are a different matter. Can a maple tree rebound after warm weather and a long shutdown? There is no definitive answer to this question. Each sugar bush has its own characteristics and will respond differently to environmental conditions.    The reality is, you can make a good season better by extending the season, but you cannot make up for the production you have lost as a result of not tapping on time. Across the state Ohio producers were tapping in January, 3 out of the last 5 years.  Only in 2014 and 2015, the years of the Polar Vortex, was tapping delayed into late February and early March. You can never duplicate the flow of a fresh tap precisely placed at the start of the season. Many of those producers tapping early in 2017 learned this lesson the hard way in 2016. As a result those that tapped early in 2017 had an average to above average seasons all because they were able to take advantage of the opportunity.

Late season runs are often marked by diminishing returns, yet some producer pride themselves on the fact that they can make syrup long after everyone else is done. The question is, what are they making and where will it end up. Ultimately the quality of the product has to be the deciding factor in knowing when to end the season. Attempts to make commercial syrup at the end of the season are usually a waste of the producer’s time and money. Sacrificing quality for quantity only results in a surplus of low quality syrup that should never reach the market place.  Unfortunately many times this syrup goes into the marketing pipeline, ending up on a store shelf, headed for the table of an unsuspecting   consumer.  This type of production and marketing practice has no place in the maple syrup Industry.

Les Ober Geauga County OSU Extension

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Filed under Maple Syrup in Ohio, Maple Syrup Quaity, Syrup Producing Weather, Taphole Sanitation

Should I Tap?

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.

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Filed under Maple Education, Maple Production, Maple Syrup in Ohio, Taphole Sanitation, Tubing & Vacuum Systems

New Consumer Maple Page Launched

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.

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Handling Your Maple Syrup Crop after the Season

 

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.

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Things You Can Do to Ensure the Quality of Your Maple Syrup

 Les Ober
Geauga County
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.

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Tips on Managing Sugar Sand

I had a comment come in recently that refers to a universal problem that many sugarmakers have. With heavy flood runs coming in the next couple days and an increased chance for heavy niter buildup here are a few tips that might help with the problem.

This producer asked:
Dose anybody have any advice on how to get this pasty mud like stuff to filter better I have been battling this for three years now and don’t know why, any advice would be greatly appreciated!

This was my answer to his question;
You have a problem that hundreds of producers have every year. So you are not alone in your question of how to deal with this problem.

Niter is caused by the mineral precipitating out of the sap as boils. Every woods if different in the amount produced.All depends on the mineral content of the soil. When we boil sap it is very similar to lime forming on a pan after you boil hard water several times.The only difference that we are keeping the niter in solution and filtering it out. That is the key to removing niter.
You have to keep it in solution when you run it through your filter. You need to keep your syrup very hot and filter it immediately.If the filters cool for a long period of time the sugar crystallizes on the filter and blocks the flow. If you are using a felt or orlon filter always use a pre-filter.In fact try to stack up several filters in layers and when the filter flow slows down just pull off the top layer and continue to filter the syrup.

If you use a filter press make sure you use enough filter aid to initially charge the filter. Even though filter presses have filter papers in between the metal plates it is the filter aid the does the filtering. Make sure use enough but do not over do it. Mix the filter aid and the syrup completely before running tne press. Keep the syrup hot and try to run larger batches. If you run small batches the filter press cools and you will not be able to run as much syrup through before you change filters. Watch your pressure and change filters when the pressure starts to build excessively. This should prevent blowouts and having to refilter.

Normally we filter with a conventional filter tank with a stack of 5 to 10 pre-filters on the tank and 1 orlon filter. I try to put enough pre-filters on for the better part of the day. After we filter we transfer to a 20 gallon heating tank. Heat to the syrup to 185 and then run it through a pressure filter into 15 gallon drums. I try to never bring syrup back to boil or more niter will precipitate out .

Hope this will help and good sugaring.

Les

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Filed under Evaporators & Finishing, Filtering, Maple Syrup Quaity

Maintaining the Quality of Maple Syrup Through the Proper Handling of Maple Sap

The taste of Pure Maple Syrup is one of natures the most enjoyable flavors. If it is produced properly the taste ranges from sweet delicate flavor to a pronounced robust, uniquely maple flavor. However, maple syrup that is improperly made or handled can be just as unforgettable for other reasons. Maple producers need to be very conscious of how easy it is to destroy the quality of the product they are producing. They need to take every precaution to preserve the integrity of this unique product. How sap is handled during the course of the season will determine the volume of high quality syrup produced. Maple syrup is made up of 98.5% sugar. The level of sugar is measure in brix’s or a percentage of the percent sugar present in the product. For all practical purposes and because pure maple syrup is almost 100% sugar we simply say that the product is maple syrup, when it reaches 66 brix or 66 % sugar. For this reason in the State of Ohio maple syrup must be finished at 66 Brix. The primary sugar in maple syrup is sucrose. There are small amounts of Glucose and a trace of Fructose present. These sugars are referred to as the invert sugars. The level that is present can determine if a maple syrup from a specific batch is usable to make certain maple sugar products. The remaining portion of the syrup is composed of various minerals Amino acids and organic acids. The most common Organic acids are Malic and Fumaric acid. These are the same organic acids found in fruit juices. The presence of these acids is a relevant fact and has a bearing on how maple syrup is processed.

The quality of maple syrup normally seems to decline as the season progresses. The sap that comes from the tree when the weather is cold and the taps are fresh will most often produce the lightest and the highest quality syrup of the season. The primary reason for this is the relatively low level of bacteria found in the sap. Research done at the University Of Vermont by Mariafranca Morselli documented the fact that sap inside the maple tree is sterile2. Because sap is normally 1.5 to 2.5 % sugar it becomes an ideal medium for bacterial growth. Once the sap reaches the taphole environmental conditions cause bacterial colonies in the sap to flourish. This bacterial growth is responsible for two processes, one inside the tree another outside. Bacteria will cause the taphole to dry out and heal thus reducing the flow of sap from that tap. Outside the tree, sap that is contains large numbers of bacteria will produce a darker grade of syrup. A study by Legace, Petri, Jacques and Roy found that “The presence of microorganisms in the sap has the ability to breakdown the sucrose molecules, the main organic component sap, into glucose and fructose subunits. These subunits react with the heat in the evaporation process to cause the darkening of the syrup and an intense, caramelized flavor.” Morselli & Wahlen also found that if you could keep the sap from being contaminated with bacteria it would produce light colored syrup almost to the end of the season. Maple producers can learn much from these studies. Keeping tapping procedures clean not blowing in the hole to dislodge wood chips, drilling holes straight and clean will help prevent bacterial growth. Cleaning spouts thoroughly before use or using some of the newer disposable spouts.

Bacterial growth that starts at the taphole will multiply and flourish as the sap is collected and stored prior to evaporation. This is the reason that sanitation is so important during the collection process Tubing systems have solved many problems when it comes to collecting sap. They have also created a few. Sap being collected with a vacuum tubing system moves sap quickly away from the tree to the collection point. It creates a cleaner environment for sap collection unless it is improperly maintained. Poorly maintained tubing presents one of the highest risks for increased bacterial growth. Stagnate sap sitting inside of a tubing will warm quickly. Research done by Morselli and Wahlen5 at the Univ. of Vermont found that the bacteria populations, sitting inside warm tubing system, will double every twenty minutes. Therefore, tubing systems need to be installed properly and maintained. Lines need to be tight and sloped toward the collection point. Research at the University of Vermont Proctor Research Center, Center Acer and Cornell University has changed the way we work with tubing. We use to set a tubing system so that you could rinse it during the season. Now we have found that by changing spouts every season and rotating drop lines at a regular interval that you can achieve a high level of vacuum line sanitation. The invention of the Check Valve Adapter by the researchers at Proctor Research Center has totally changed the way we think of taphole sanitation. The research done at proctor documented that sap actually back siphons into the tree when vacuum is no longer present. The CVA prevents that back siphoning from occurring. The other thing that was learned was that if we can maintain vacuum on the lines even during periods of minimum flow we can keep the lines cooler and bacterial growth at a minimal level. The result is that in many maple operations the only time that vacuum is turned off is when the temperature goes below freezing. We are definitely changing the way we run our vacuum tubing systems and it has not only improved syrup production but also syrup quality. At the end of the season all of the collection lines need to be thoroughly cleaned and drained. If possible they should be rinsed before the start of the next season. Sanitation is no less important in bucket operations. Buckets should be washed before the start of every season. During the season sap needs to gathered often.. At the end of the season buckets need to be washed and dried and stored quickly.

Once the sap arrives at the sugarhouse it should be processed quickly. Do not allow sap to sit in open tanks for long periods of time. Collection tanks need to be drained and washed down between runs. To speed up processing evaporator size needs to be properly matched to the volume of sap coming into the sugarhouse. Producers who struggle to keep ahead of the sap flow and allow large volumes of sap to sit un-processed for long periods of time often struggle to make top quality syrup. There are several techniques that can slow bacterial growth and speed up the processing time. Sap can be exposed to ultra-violet light. Morselli and Wahlen found that sap treated with in-line ultraviolet lamp will reduce bacteria by 99.4 % early in the season and reduce bacteria by 86.2 % late in the season. The evaporation rates can be increased by using pre-heaters or enhanced evaporator units such as the Steam-A-Way or Piggyback. By far the most popular means of cutting down on processing time is by using a Reverse Osmosis Machine. The invention of the RO has revolutionized the maple syrup industry. Because of the use of modern RO technology, extensive expansion of maple operations is now possible. Modern RO machines can concentrate sap from 2% to up to over 20% before it ever goes through the evaporator. However, a word of caution, the sap that has been run through a reverse osmosis process is subject to increased bacterial growth. Concentrated sap needs to be processed as soon as it comes out the RO. to prevent darkening of the finished product.

The final step in the process is the proper setup and operation of the evaporator and the maple syrup filtering systems. Once again proper sanitation of all the processing equipment is very important if quality is to be maintained. There is an extensive look at operating and maintaining evaporators in previous posts on this blog. The purpose of this post is to get you to thinking about the importance of sanitation and the part it plays in the process of making maple syrup. The beginning of the season is the time to adopt good sanitation practices.

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Tapping Basics

Author: Les Ober Geauga County OSU Extension

The recent warm spell had many maple producer fired up and ready to tap. If you frequent the maple chat lines like Maple Trader or Sugar bush Info you heard a lot of speculation on when where and how to tap. There appears to be as many theories on tapping as there are tap holes. Let’s look at the tapping process.

The first thing to remember about tapping trees whether you tap early or late is that you only have one chance to get it right. Making a mistake the first time can screw up the whole season. It is more important how you tap than when you tap. First we need to take a look the trees and determine which ones to tap. To do this we follow a set of tapping guidelines that are published in the North American Maple Syrup Manual. Depending on whether you follow the traditional or the conservative guidelines you will be tapping a tree no smaller in diameter than 10 to 12 inches.  This is where a recent study done by the Univ. of Vt. Proctor Lab in Underhill Center VT adds clarity to the ongoing debate. The research work was done by Dr. Abby van den Berg at Proctor at high yield sugar bushes throughout Vermont. High yield was operations with vacuum systems using 20 plus inches of vacuum to collect sap. What Dr van den Berg found out, was that the current conservative tapping guidelines of 12 inches in diameter minimum size was correct for tubing systems using modern high vacuum collection systems.

The study compared the percentage of functional and non-functional wood in the trees of different diameter and applications. Functional wood is new growth wood, the kind you can tap intoand get peak production. Non-functional is the dead wood that is left behind as a result of tapping. This wood is the stained non-productive wood that you see in cross sections of maples that have been tapped.  At 12 in. diameter a healthy tree will regenerate enough new growth (90% or greater functional wood) to maintain tree growth and adequate sugar production to maintain tree health. Trees under 12 inches saw a steady decrease in the percentage functional wood at an earlier age. This is important because you want to consistently be tapping into new wood year after. If the percentage of functional wood is on the decline this makes it harder year after year to find new wood to tap into. It could lead to a decline in overall tree health and productivity. A quick way to determine tree size is to use a rope 38 inches in. long. If you get to a tree and you place the rope around the tree and the two ends of the rope do not touch you have a tree at least 12 inches in diameter. There were other factors that could influence the reduction of functional wood.

The standard drop line length recommended and used in this study is 30 inches. It was found that if the drop length was reduced it intern reduced the tapping zone of that of the tree. The result was a decline in the functional wood area at an earlier age. This is very important because as we work on drop lines making repairs or installing new spouts it is not uncommon to see them getting shorter and shorter. This greatly reduces the tapping area on that tree. If you are following the new tap sanitation recommendation of replacing drop lines every other year you can overcome this problem of short drop lines by replacing them with new 30 inch drops. Also consider on trees with very large diameters you may need a longer drop line. Another factor is using the old style large spout. This will increase the size of the non-functional wood for each tap. It is always wise to use the new 5/16 tap if you want to promote tree health.

The study at Proctor used a 1 ½ tapping depth with the 5/16 spout throughout the study. That is the correct tapping depth for today’s maple operations and maintaining that depth can be difficult. One way is to put a piece of tubing over the bit exposing 1 ½ inches of bit allowing you to reproduce that depth each time you drill. Also consider how you drill. Make sure you hold the drill straight drilling a round hole, angled slightly downward. Wiggle the drill and you have an oval shape hole that will leak not only sap but vacuum. Do this enough time and you will be losing vacuum all over the place. Use a sharp bit that cleans the shavings out of the hole. Shavings left in the hole will attract and promote bacterial growth.  The spout must be seated properly but do not over drive the tap causing it to split on top and on the bottom. Use a light tapping hammer and leave the sledge hammer at home. Today most producers use cordless drills to tap. It is important to use a drill you are comfortable with, not only the first hour but at the end of the day. The new drills with Lithium batteries are light and are a good investment both in battery longevity and ease of handling.

Establish a tapping pattern that you use every year, such as 6 inches over and 6 inches up or moving to the opposite side of the tree.  Do not try to tap a tree year after year on the south side because someone told you it would run early. With buckets expand you dumping zone to include high and low buckets.  What is important is getting the job done right the first time. Remember there is pride in bragging you tapped 1000 today if half of them are screwed up. Slow down and make your work count. Here is the website for the Univ. of VT factsheet http://nsrcforest.org/project/sustainable-tapping-guidelines-modern-maple-syrup-production

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Filed under Taphole Sanitation, Tapping