Sanitation

Ohio Maple Days 2021 Presentations AVAILABLE

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Despite being virtual due to COVID-19, 2021 Ohio Maple Days – or more accurately Ohio Maple Day sans the “s” – was a success.  The audience, two hundred or so strong, heard presentations on tapping and updates from our ACER grants in addition to how production might be increased with red maple.  A big thanks to this year’s speakers and an extra round of applause for the committee who worked hard on an event that looked quite a bit different than in years past.  One silver lining to having a virtual event is that the sessions are easily recorded.

Visit the Ohio Woodland Stewards Maple page and scroll to the bottom of that webpage to access the different presentations.  Let us know what you think and send us any questions, comments, concerns, or suggestions to talk topics for next year!

Handling Sap and Syrup During the Season

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The maple season is now underway and this is a good time to talk about handling your sap during and after collection. How you handle your sap prior to boiling will strongly affect the quality of the syrup you make. When quality syrup is the goal, timing is everything, and the clock starts as soon as the sap leaves the tree and doesn’t stop until it hits the evaporator.

When sap comes from the tree, it is sterile. That all changes once the sap starts to drain from the taphole. The air and surfaces surrounding the tap contain an abundance of microbes. The sap supplies the food source and a media for the microbes to grow and multiply. Research at Center Acer in Quebec found 21 different strains of microbes present in sap. At first you would think that could be problematic, but the reality is, you need certain strains of bacteria to produce the color and flavor that is unique to maple syrup. For microbial growth you also need the right temperature. Once the environment warms the sap, microbes multiply rapidly. Producers can monitor the potential for microbial growth by checking the temperature of sap. If the temperature is close to freezing, growth is suppressed. Below 40 degrees Fahrenheit, the growth of bacteria is slow, but once the temperature rises above 50 Fahrenheit microbial growth is rapid. The chances for 50 degrees and above temperatures are greatest at the end of the season.

When sap leaves the tree, the sugar is 100% sucrose. Once the sap is exposed to bacterial action, a small fraction of the sucrose is converted into glucose and fructose, often referred to as “invert sugars.” When maple sap containing sucrose, glucose, and fructose is heated, you create an amber color and a unique maple flavor. The problem is when undesirable bacteria begins to outnumber the good bacteria. This changes the chemistry of the sap. As the invert sugar level increases, syrup begins to take on a darker color and a stronger maple flavor. This produces the different grades of syrup. Syrup early in the season has a light color and very mild flavor. The maple syrup produced at the end of the season is often darker and stronger flavor. Syrup containing higher levels of bacteria can develop a very strong almost bitter off-taste known as sour syrup. The syrup consistency takes on a thick almost rubber like appearance and is often referred to as ropey syrup. Sour sap is often confused with buddy syrup because it happens most often at the end of the season. Buddy syrup is caused by sap coming from trees where the buds are getting ready to bloom. The chemistry is completely different from sour sap. Sour sap can happen any time during the season when a warm spell causes extreme flushes of bacteria growth. Sour sap can be prevented with good sanitation practices. Buddy syrup is a natural occurrence every year at the end of the season.

The quality of syrup produced from buckets and bags is best early in the season. Once the hole is drilled and the spout is exposed to the air, microbial development and taphole healing begins. Your season has begun, and you are now on the clock. A normal season for a bucket, bag or gravity tubing producer is 4 to 6 weeks. During the cold periods early in the season, the sap stays fresh just like it would if you put it in your refrigerator. Keep your sap below 40 degrees Fahrenheit and you are fine, but let it heat up to over 50 degrees and you asking for trouble. That happens readily at the end of the season. What many producers forget is that the bucket is an incubator for bacteria if it is not cleaned out regularly throughout the season. Leaving sap sit in a dirty bucket for any length of time is a problem. Remember bacteria does not grow in a clean dry bucket. If you are in a warm spell wash out your buckets and place them upside down next to the tree. If you are in a extended cold period, you should collect your buckets and let them hang until the next run. And never let stale sap sit a bucket, hot or cold.

As for tubing, we have discussed tubing sanitation multiple times over the years and those articles are in the Ohio Maple Blog Archive. Keep your lines as clean as possible throughout the season. This is difficult unless you are on continuous high vacuum. I know it sounds expensive to run the pumps 24/7, but it works to your advantage by keeping the lines cool and dry when the sap is not running. Another essential is to follow the tubing sanitation guidelines, installing new spouts every year, and new tees and drops every three years. You will improve the quality of your syrup.

Once you get the sap to sugarhouse, there are additional things you can do to improve quality. Sap that is going to be stored for longer periods of time needs to be stored in a stainless steel tank. Avoid poly tanks for sap storage. Plastic tanks are incubators for bacteria. Older galvanized tanks, like galvanized buckets, need to be discarded because of the risk of lead contamination. For the backyard producer, make sure your tank is in the shade. Pack around it with snow if possible. You can even freeze some sap and put it in the tank during warm spells. What ever it takes to keep your sap cold, take those necessary precautions. Anytime your sap reaches 50 degrees Fahrenheit and you can’t immediately cool it back down, boil immediately.

What about the evaporator? Boil your sap as quickly as possible. If you are using a reverse osmosis machine, make sure you do not let your concentrate sit. Boil it as soon as it comes through the RO. You double, triple, and in some cases, quadruple the sugar concentration in your sap, and bacteria builds fast in concentrated sap. If you are using a small evaporator, it is a good idea to drain and flush your rig. Leaving partially boiled sap on an evaporator in a warm sugarhouse can result in ropey syrup. Once the syrup is filtered get it into a barrel or a container as fast you can. Do not let it sit around. Pack your drums hot and do not open them until you are ready to use them. Do not store syrup drums in a warm building. Move them into the basement where it is cool or package the syrup at 185 degrees Fahrenheit shortly after the season. From the tree to final container, paying attention to details pays big dividends.

Author: Les Ober, Geauga County OSU Extension

When the Season Comes to an End

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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 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 are easy to clean with a pressure washer. We found that a tank washing nozzle that fits your pressure washer is a valuable tool. The specially-designed nozzles enable you to spray to the side and reach areas that a standard spray tip cannot reach. There is no substitute for stainless steel equipment if you can afford it.

Plastic totes and poly tanks have become popular because they are relatively inexpensive but they are harder to clean. Plastic totes, while affordable, may only last about two or three seasons if you get off your cleaning schedule. It does not take long for the plastic to become so contaminated with bacterial spores that you have to discard and replace. However, if you keep poly tanks cleaned they will last for years. Another simple tip is to clean as soon after the season ends as possible. Allowing totes and tanks to sit dormant allows bacteria to build and grow making cleaning more difficult.

Your evaporator needs to be sugared off and flushed out as soon as possible. I often flush the pans with clean water and then refill them with permeate from the RO and let them soak. If permeate is not available, use water. I will drain and refill the pans with clean water and then add the proper amount of pan cleaner following label directions. Once the pan cleaner has done its job, I drain the pans and use a high pressure washer to finish the job. Do the process correctly and your pans will look brand new. Make sure all your float boxes are clean, replace gaskets if needed. Soak your auto draw off temperature probe and your hydrometer in a 5% vinegar solution to remove any residues or films. The thermocouple in the auto draw off probe works best when there is no niter on the probe. Clean your filter press thoroughly and lubricate parts with a food grade lubricant. It is good practice to remove all extra filters from your sugarhouse and store them in your house, somewhere dry and rodent-free. If you use a filter tank, you will need to clean filters and make sure they are completely dry before story to ensure no mold will develop over the off-season. Any filters with problems, even minor, should be discarded, and you should purchase new inventory for the next season.

Reverse osmosis units (RO) should 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, return your membranes to the storage vessels with a cup of permeate in each one. Once everything is clean, you should send the membranes in to your dealer 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 and 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. Because evaporators and ROs require the use of chemicals that are incompatible – phosphoric acid and basic soap – keep them separate and out of reach of children. Be careful when you mix pan cleaner and always follow the directions on the label.

The most controversial portion of a maple system to clean is most certainly the tubing. It seems everyone has his or her own way of dealing with the miles of tubing stretching through the woods. I have cleaned tubing just about every way possible over the years. We have sucked water, pumped water and air, water only, air and tubing cleaner, and just plain did not clean at all. In my experience, using water and air worked well until we tried to pump up too steep of slope and had a blowout that may have 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. The method we now use seems to work. We pull taps with the vacuum, nip off each old spout, and immediately use a Stars Company (out of Quebec) line plug to seal the drop line and maintain vacuum on the system. Done properly, the sap in the lateral line will not suck back into the drop line. We then use a paint marker to mark the old tap hole which greatly speeds up next season’s tapping process. Once all of the taps are out, we back flush the mainlines with clean water. Next we close all of the main lines and open the end of each lateral opening long enough to pull air through the lines and keep vacuum on the system. Doing this should remove 80% of the liquid from the lateral and main lines. At this stage, we successively open the ends of each main line and let air in with the vacuum on. Once the vacuum on the entire system drops to zero shut off the pump. At some point before the next season, we then install new spouts on all the drops and let the lines air out completely. This method may seem excessive but it does work. We have a small amount of green sap at the start of the season, but nothing we could not easily filter and could possibly have been avoided by flushing the system again before the season.

A word of caution when it comes to using tubing cleaners. They have to be completely flushed from the lines before the next season. Never use Isopropyl alcohol – it is illegal in the United States. Also be aware that some cleaners attract Mr. Bushy Tail and his friends – never a good thing for tubing operators.

Once your system is cleaned, bring in all releasers and clean and sanitize them thoroughly. They are made of PVC which makes a good home for bacteria. Go over the mechanism and use lubricant provided by the manufacture to lubricate all of moving parts. The last task is to care for your vacuum 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. The 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 will be ready to go for next season. Lastly, make sure you transfer pumps are drained and stored somewhere that will not fall below freezing.

Author: Les Ober, Geauga County OSU Extension