Maple leafFrequently Asked Questions

Minnesota Maple Syrup Producers' Association - Reliable information on Maple - Tapping Maple Trees - Gathering Sap in the Woods - Evaporating Sap / Finishing the Syrup - Filtering and Finishing Syrup - Bottling - Licensing / Selling to Public - End of Season / General

The following information is intended to help answer basic questions frequently asked about producing maple syrup and about the Minnesota Maple Syrup Producers Association. It is not intended to provide everything needed to make quality maple syrup. There are many printed and on-line resources that can provide additional information and more detailed answers to your questions. Better yet, become a member of the MMSPA and get your answers first hand.

Minnesota Maple Syrup Producers' Association


Q. What are the benefits of becoming a member of the MMSPA?


A.  The price of a single membership is only $25 annually, but the information, sugar house tours, friends and contacts are, as they say, “priceless.” MMSPA members pride themselves in learning from each other and sharing information among all members, beginning or experienced. Members also receive the quarterly MN Maple News, a subscription to the North American Maple Digest, member alerts and access to the web site bulletin board. Meetings are held twice a year, rotated around the state and include tours of member maple operations and other local attractions.


Q. How do I become a member of the MMSPA?


A. Membership forms (printable or online versions) are available on the Membership page of this website. Just print off and complete a copy and send it along with your dues to our Treasurer; the address is on the form. Alternatively, you can complete and submit the online form.


 Reliable Information on Maple


Q. Is there one reliable source of complete information on producing maple syrup?


A. Purchase and read a copy of the North American Maple Syrup Producers Manual. The manual is considered the “bible” of maple production and was produced by Ohio State University Extension in cooperation with the North American Maple Syrup Council. The revised second edition is dated 2006. The manual has good, current, research-based information on “everything maple”. It is available wherever maple equipment is sold (see links to equipment dealers on this site). The manual can also be ordered directly from the Ohio State University, Extension Department. Ask for Bulletin #856.   http://estore.osu-extension.org/  Cost of the manual in soft cover will probably be in the $20-$30 range.


Q. How about other sources?


A. Visit the web sites of the Land Grant University Extension departments in the maple producing states from Minnesota to New England including Minnesota, Wisconsin, Michigan State, Ohio State, Vermont, Cornell in New York, New Hampshire and Maine to name a few. Those same states all have maple producer associations which are excellent sources of information and links to industry sources. You will find many helpful “links” to these organizations on our Links page.


Tapping Maple Trees


Q. I tapped a few trees in my yard. The sap started to flow, but then stopped. Did I do something wrong?


A. Even during the “sugaring season”, it is not unusual for sap flow to start and stop every few days. You likely did nothing wrong; wait for temperatures and barometric pressures to change to more favorable conditions. Remember, sap runs best on sunny warm (45-50 degree days) which follow hard freezing nights. The best maple seasons have multiple freezing/thawing cycles in the early spring.


Q. How do I know when to start tapping?


A. If you put out just a few taps, you can watch the weather forecast to determine when a stretch of warm (45-50 degree days) days and cool, below freezing nights (in the 20’s or below) is predicted. Since it takes a few days of warm/cool for sap to begin to run, you will be able to tap in time for the first run.
•    Exact dates cannot be predicted because sap flow depends on geography (earlier in southern MN, later in northern MN) and temperature.
•    Ideally, you don’t want to tap your trees too early (say in January) because the holes may begin to “dry out” before the season starts. Large producers with thousands of taps typically must begin to tap “earlier” in order to have all taps set at the beginning of the season.
•    Some producers tap one or two “indicator trees” early. When they first begin to drip sap, it is the signal to tap the remainder of the sugar bush.


Q. How big does a maple tree need to be before it can be tapped?


A. The North American Maple Syrup Producers Manual recommends tapping trees no less than 10" in diameter, chest high.  Use one tap per tree until they are at least 18" diameter, (chest high) then two taps per tree can be ok.  Tapping more than two taps per tree is no longer recommended, regardless of size.


Q. Can you use the same tap hole every year? How about tapping the same tree year after year?


A. Once a tree is large enough to tap, and if the tree remains healthy, the same tree can be used for many, many years. You should drill a new hole at least 6 inches away from the prior tap every year, because the previous year’s tap hole will result in some scarred tissue. Do not “girdle” the tree by tapping in an exact circle at the same height year after year. Try to only tap maples with full healthy crowns. Avoid trees that have been recently damaged or that look unhealthy.


Q. How deep do you drill for tapping?


A. Drill approximately 1.5 to 2 inches deep (maybe a bit more if the bark is thick), and slant the drill slightly so that the hole (and therefore the tap) slants downward.
•    New holes should be 4 inches to the side and 6 inches above or below the previous year’s hole.
•    Find healthy white sap wood. Avoid tapping into rotted wood or hollow spots.


Q. I have heard that some producers put bleach or formaldehyde in the tap hole to “sterilize” before inserting the tap? Is that permitted or recommended?


A. In a word, absolutely NOT. The use of formaldehyde in your maple operation is against the law. If you wouldn’t drink it, do not introduce it into your sap or syrup. Further, resist the temptation to blow into your tap holes to clean out wood shavings as this will contribute to contamination and bacteria growth in the hole. Clean out shavings and fragments with a clean metal wire or small nail as necessary.


Q. How hard do you pound the tap in? And how far in do you drive it?


A. Seating the tap is NOT like pounding in a nail! You only want a snug fit between the tapered tap and the hole you just drilled. Only pound on the tap moderately, until the tap is firm. If you pound too hard, especially in hard-freeze conditions, you can crack the tree, making a larger wound for sap to leak and for disease or pests to enter.


Gathering Sap in the Woods


Q. Can I use milk jugs to collect sap? How about detergent containers or used buckets?


A. Many small producers use various food grade containers for sap. Plastic milk containers, although small, can work well for the hobbyist. Use common sense, however, because maple sap can take on “off” flavors from certain collection containers. Specifically, avoid re-using containers from strong-smelling foods such as pickles, sour kraut, strong cheese, etc. Absolutely avoid using non-food-grade containers such as paint buckets, detergent containers, sheet rock “mud” buckets, petroleum containers, or even rusty coffee cans, etc. As a general rule, avoid anything “non-food grade” in the production of maple syrup.


Evaporating Sap / Finishing the Syrup


Q. What are the best fuels to use for evaporating maple sap?


A. Most small producers initially boil their maple sap over a wood-fueled fire for several hours in a pan especially fashioned for boiling sap. Concentrated sap is typically removed from the wood fire before it is “done,” and then “finished” over a gas stove where the heat can be more effectively controlled (i.e. shut off) when the syrup is “done.” Large commercial producers with thousands of taps may use LP gas or fuel oil to fire their large capacity evaporators.  Equipment manufacturers are constantly introducing new technology to make modern evaporators more efficient.


Q. How will I know when my syrup is “done”?


A. Syrup is “done” when it reaches the proper concentration of sugar and other solids. Fresh raw sap typically runs about 2%-3% sugar and finished syrup is evaporated to 66.5% sugar. There are several tools and techniques to help determine when syrup reaches the desired concentration.
•    The most basic technique used by the “old timers” before modern instruments were devised was to check for “sheeting” or “aproning” of the syrup as it was cooking down. Take a large spoon and get a little syrup on it over the cook pan. Tip it sideways, and watch the syrup come off the edge of the spoon. If the syrup is done, it will form a thin sheet rather than dripping off. For hobbyists at home, this technique may be “close enough”.
•    Some producers use the temperature of the boiling syrup to determine when syrup is “done.” Maple syrup at the correct density boils at 7 degrees above the boiling point of pure water. However, if this method is used, the producer needs to know the exact temperature at which pure water boils at that location when the syrup is actually boiling. The temperature at which water boils varies with elevation and barometric pressure (i.e. changes with the weather) from day to day and even hour to hour. The boiling point of water is 212 degrees F only at 29.92” of barometric pressure, basically at sea level. You will need a thermometer calibrated by 1/4 degrees or less to make this system work very effectively for you.
•    A very reliable-- and not overly expensive-- tool used by many producers is the syrup hydrometer. It is specifically calibrated to measure syrup density by floating in a sample of hot (or room temperature) syrup. By repeatedly taking a sample from the finishing pan and floating the hydrometer in the hot syrup, the density can be monitored until it reaches the desired mark. The syrup is then “done” and “boiling” should be terminated.
•    Another tool frequently used is a syrup “refractometer.” It works very well for room temperature syrup and uses only a drop or two of syrup on a light prism. By holding the device’s eye piece to a bright light, it measures density based on light refraction through the instrument’s prism.


Filtering Finished Syrup


Q. What is wrong with my syrup? It looks very cloudy?


A. It’s likely the “cloudy” look is due to minerals in the syrup. The minerals are called “niter” or “sugar sand” and can be removed by proper filtering of the syrup. Some years, and some times during the season, can be worse for niter than others. A good “gravity” filtration system using special cloth/orlon filters can work well.
•    Another option may be to let the niter settle to the bottom of your syrup for a few days. If you do this before bottling and if you are careful, you may be able to use most of the clear syrup, tossing out the cloudy sediment-laden syrup at the bottom of the container. Niter is not necessarily harmful if you ingest it. You may be OK with just using the syrup cloudy if it is for your own personal use.
•    For larger producers, commercial pressure filter presses are available from maple equipment suppliers. “Presses” are very effective in producing clear clean maple syrup, but can be expensive pieces of equipment.


Q. I washed my cloth/orlon filters after last season and now I’m having trouble filtering and my syrup has a bad taste. What might be the problem?


A. When washing cloth/orlon filters, it is important to NOT wring them out. You may squeeze them, but the wringing motion can actually break the fibers and you will not get good results. You also should not add anything to wash water (detergents or bleach) when washing cloth/orlon filters. Again, since maple takes on flavors, you may taste those things in next year’s syrup if you do. It is best to clean your filters in hot/boiling water only.


Bottling


Q. I heat up my syrup before I bottle it but I’m getting a lot of spoilage. What can I do?


A. Many recommendations are out there regarding the proper temperature for bottling, but the consensus is syrup should be heated to 180-200 degrees when bottling. Many say 180 degrees minimum; however, you need to remember that the syrup will cool as you work, so you may want to heat it closer to 200 degrees before you bottle. You can then be sure it is still 180 degrees in the bottle. Put a thermometer in your bottling pan. A few more tips:
•    Be sure caps are tightly sealed, and then tip filled containers on their sides to cool. This sterilizes the neck and cap of the bottle and also makes the cap form a tight seal.
•    Another related problem may be that the syrup was not “finished” to at the proper sugar concentration of 66.5%. Generally, if syrup is under concentrated it will develop mold sooner and if it is over-concentrated it will develop crystals in its container.


Licensing / Selling to Public


Q. I love making maple syrup. I add taps every year, and I now have more than my family and friends can use. I think I’d like to sell to the public. Do I need a state license to do that? How do I obtain a license?


A. Generally speaking, a license from the MN Dept. of Ag is required to legally sell maple syrup to the public unless all sap is obtained from trees on your own land and no other “off farm” inputs are used in your operation (i.e. sap from neighbors). However, all maple operations selling to the public are subject to inspections by the MN Dept. of Ag, though the enforcement of that provision cannot be confirmed. The best advice we can give is to contact your local MN Department of Agriculture inspector by calling the MN Dept. of Ag at 651-201-6315 or Email at This email address is being protected from spambots. You need JavaScript enabled to view it. .There are many rules and regulations regarding licensing and the types of licenses that may required depending on your operation. Your inspector can listen to your plans and your specific circumstances and tell you what is and what is not required.


Q. What is the required information on labels for maple syrup produced and sold in Minnesota to the public?


A. According to an MDA official who spoke to our membership at the spring meeting at St. Olaf College in 2008, the minimum requirements for labeling include 1) the identity of the product (i.e. pure maple syrup), 2) the size of the container (i.e. 8 ounce, 12 ounce, 16 ounce, etc.) and 3) the identity and address of the producer. Use of the respective USDA grades is optional, ( not required) for maple syrup produced and sold in Minnesota. However, if grades are displayed, the “grades” of syrup must meet USDA minimum standards for each grade displayed.


End of Season / General


Q. I made maple syrup for the first time this year. I tapped, gathered, boiled and now I am ready to wrap things up. What do I do about the holes in the trees? Do I need to plug them with something? How do I get the sap to stop coming out?


A. As the trees get ready to make leaves and the temperatures get warmer, the sap will stop flowing on its own. When you remove the tap, the tree will heal on its own. You don’t need to do anything to the holes. Let them dry up and heal by themselves. Remove all taps, clean/sterilize all equipment, and enjoy dreaming of next spring.


Q. I have used up my canning jars and I’d like to get real maple syrup bottles for next year. I also want to get some better equipment. Where do I get these things?


A. From the MMSPA website, you may link to area equipment dealers who are also MMSPA members. These equipment dealers are very knowledgeable and will be great resources for you. There are many additional suppliers and manufacturers of maple equipment to be found “on line”. Talk to other MMSPA producers and ask where they obtain their supplies.


Q. What is the recommended way to clean my taps, buckets, etc at the end of the season? How much rinsing is recommended?


A. Most sap gathering equipment and lines can be cleaned by using food grade hydrogen peroxide (leaves no residue if properly rinsed, but is more expensive) or a bleach solution (cheaper but can leave salts that squirrels enjoy and any residue can affect next year’s sap). If you use bleach, a triple rinse is recommended.
•    Some equipment can be washed with hot water.
•    Some equipment, such as your buckets, can be cleaned with a mild dish soap solution…. BUT thorough rinsing is essential.
•    Remember that anything you use to clean MAY give an off flavor to your syrup if not properly and completely rinsed.


Q. How about cleaning my evaporator pan?


A. Special care should be taken not to scratch the inside surface of your stainless steel cook pan by scrubbing with an abrasive. Some producers soak the pan in hot water and vinegar or use special commercial pan cleaner solutions available from equipment suppliers. Be sure to follow up with a complete high pressure rinse using a hose or power washer. The underside of the cook pan also needs thorough cleaning to remove soot which otherwise impedes the heat transfer when boiling.


Q. I just want to build a basic "back yard" maple sap cooking set-up. Where can I learn how to build a small "cooker"? How do I locate needed equipment?


A. Again, we refer you to the N. A. Maple Syrup Producers Manual and to our web site links to member-equipment dealers. They can be a great resource for you. Go on line and search the Land Grant University web sites for maple syrup production. Check out Minnesota, Wisconsin, Michigan State, Ohio State, Vermont, Cornell in New York and New Hampshire for a start. There are many books on making maple syrup. Some are available at your public library; some are sold by equipment dealers.


Q. I hear about grades of syrup, but I don’t know what that means. How do I know what grade my syrup is, and does it matter?


A. Generally speaking, grading of syrup is only required in Minnesota if your customers want it graded, or if you are selling syrup outside of Minnesota or for maple syrup competitions. Minnesota does not require grading of syrup produced and sold here. However, if you claim your syrup is a certain grade it MUST meet that USDA grade.
•    The various states and provinces where maple syrup is commercially produced have various grading requirements. The USDA has grades based primarily on the color of syrup. Grade A (considered table or pancake syrup) has three levels: light, medium and dark amber. Beyond that (darker than “dark amber”) is Grade B. which is usually thought of as cooking grade. It is stronger flavored and darker than many people care for on their pancakes. Currently, the industry is working to adopt consistent maple grading standards.
•    Color of syrup, or grading, can be accomplished by the use of a grading kit. Most grading kits consist of pre-filled colored sample bottles or color slide. You fill a small sample jar with your syrup and compare it to the colored solutions or slides in the kit to determine grade.


Q. My syrup has a bad smell and/or a bitter taste. What gives?


A. There can be many reasons for bad smells and bad tastes or “off flavors” in maple syrup. Some are “natural’, others are the result of poor practices. Off flavors can be the result of one or more of the following: You may have waited too long to boil down your sap. Sap can go bad if it is not cooked when “fresh” and kept cold while in storage. Bacterial problems increase dramatically as the season progresses.
•    Your sap may be too late in the season. When the trees begin to bud the chemistry of the sap changes and both the sap and the resulting syrup develop off flavors. When sap becomes “milky” or yellow and/or develops an odor, it is probably time to call it quits for the season. Taste (and smell) a sample of your raw sap… you can tell right away!
•    You may have cleaned equipment with something that gave off a taste (bleach or detergent) without adequate rinsing. You can never “over rinse” your equipment after cleaning.
•    You may have used a storage container that was not food grade or clean enough that gave it the off taste.
•    You may have tapped an unhealthy tree or tapped into bad wood which introduced “bad sap” into your operation.