How to Make Maple Syrup

Reader Contribution by Carole Coates
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Last week, I wrote about the joys of backyard maple syrup making – the knowing-we-can-do-it satisfaction I get from making my own syrup. In this article, I share some of the how-to details so you can do it, too. It’s not hard, but there are a few things you need to know to be successful. 

There’s nothing quite like the I-made-it-myself taste of homemade maple syrup.

Timing is Everything

The window for collecting maple sap is as critical as it is brief – a month or less. Watch for consistently low temperatures below freezing and equally consistent highs above freezing. Sap-collecting time is over once the trees begin to bud. Syrup will get an “off” taste then.

Select and Tap Your Trees

The best time to identify maple trees on you property is when they’re in leaf. Mark them with surveyor’s tape or a squirt of spray paint for easy identification later. Select healthy trees at least twelve inches in diameter (not circumference). Use only one tap for a tree that size. The larger the tree, the more taps you can use. Minnesota’s Department of Natural Resources says two spiles for a 15-19” diameter tree; three for 21-24”, four for a 25” or larger tree.

To tap a tree, first choose a spile—a purchased metal one or one you make yourself. Drill a hole in the tree (about 4″ above ground) 1½ to-2” deep (depending on bark thickness) angling your drill slightly upward so the sap can flow downwards. Hole diameter should match spile diameter. With a hammer, tap the spile into the tree. It needs to fit snugly and stay put, but tap gently to avoid damaging the tree.

Purchased spiles may come with a hook for hanging a collection bucket. Food-grade buckets can be purchased at home improvement stores. We chose a system that includes hookless spiles, plastic collection bags, and galvanized bag holders. 

Once the season is over, immediately remove spiles. Be gentle too avoid damage and to allow the tree to heal. Clean and sterilize equipment, then store for use next year.

Collecting and Storing Sap

Collect sap daily. In a perfect world, you’ll evaporate sap the day it’s collected, but things don’t always go as planned. If you don’t have enough sap (you should start with at least ten gallons) or if you must delay evaporation for some other reason, store the sap (covered) in a cool, shady place. Aim for 38 degrees or lower. Otherwise, the sap may spoil.

Here’s a trick to speed up the evaporation process. If it’s cold enough, some of the liquid may freeze overnight. Discard the frozen part. What’s left will be more concentrated and take less time to boil down.

The Evaporation Process

Evaporation is the technical part of the operation, but it’s not rocket science. You need an outdoor heat source (fireplace, wood stove, turkey fryer), a large cooking container (aluminum will affect taste), a candy thermometer, and a skimmer. The greater the surface area, the faster the evaporation. A lasagna pan has proportionally more surface space, but a deep pot lets you work with more liquid at a time.

Fill the cooking container no more than 2/3 full of sap and turn the heat up high. If using firewood, aim for a roaring fire. Keep heat consistently high. Once the liquid boils and begins to reduce, add more sap a little at a time—you don’t want to lose the boil. I’ve developed a two-step operation, first heating the new liquid in an old electric teapot. As soon as it begins to boil, I add it to the larger pot and begin the process again.

There’s no need to stir. In fact, you shouldn’t, but remove any debris with a skimmer.

A candy thermometer will help you determine when to remove the sap from its heat source. Rule of thumb: when the thermometer reads seven degrees above the boiling point, which varies by elevation. If you don’t know yours, contact your local extension service.

Boiling ten gallons of sap down to one quart of syrup takes a long time—a really long time. But as it nears the finish, the process speeds up amazingly fast. Look away for a few seconds and it may be too late. Once the liquid has mostly cooked down and you’re no longer adding new sap, it’s best to transfer it to a smaller pot, which gives you more control. If you have a good ventilation system, you may want to finish your batch on the kitchen stove. Otherwise, an outdoor camp stove is an excellent alternative.

Yields Will Be Low

If the trees you tap are sugar maples, expect about a quart of syrup for each ten gallons of sap. Other maple varieties also make excellent syrup but their sugar concentration is lower. It takes more sap to get that quart of syrup, up to one-third more for some varieties.

Finishing Up

Filter the syrup as soon as it’s removed from heat. It’s much more difficult after the syrup cools. For this task you can use a coffee filter or a purchased orlon or wool bag made for this purpose. Filtering can take an excruciatingly long time. Still, you should do it to ensure a pure product. 

If you have more syrup than you can store in the refrigerator and use within a few weeks, freeze or can it. Freezing keeps it fresher and is easiest, assuming you have adequate space. Just start with hot, sterilized mason jars. Use wide-mouth jars and leave an inch or two of air space for expansion. Add lids. I recommend Ball plastic lids, which can be found most anywhere canning supplies are sold. Store upright—the syrup will not freeze solid.

To can syrup, you also need clean, hot canning jars. Use an approved water bath canning process, like this one from the National Center for Home Food Preservation: http://nchfp.uga.edu/publications/uga/using_bw_canners.html. Specific information on home canning maple syrup is woefully scarce, but I use the same process as for making jams: leave ¼ inch head space and process for ten minutes (at sea level). Add a minute of sterilizing time for each 1,000 feet of elevation. It’s important that both jars and syrup are hot—at least 180 degrees. If the syrup cooled during the filtering process (chances are it has), reheat it.

According to some sources, including the University of Maine’s extension service, it isn’t necessary to process if you’re using hot, sterilized jars and your syrup is at least 185 degrees when you fill the jars. https://extension.umaine.edu/publications/7036e/

Sugar Sand

After the syrup is filtered and jarred, you’ll likely notice a light-colored filmy deposit in the bottom of the jar. Not to worry. Known as sugar sand, it’s a deposit of naturally occurring minerals, mostly calcium malate, and it’s perfectly safe. Some people like it; some don’t. I’ve heard some folks use it as a sweet spread on toast in lieu of jam. But if it makes you wrinkle your nose, just stop spooning out the syrup when it reaches sugar sand level.

A Few Interesting Facts

There are those who drink sap straight from the trees or use it for cooking water. It’s viewed as a tonic and is a common practice in Korea. You may have even seen sap water sold in stores.

Maple syrup is mostly sugar, so it should be used in moderation. However, it does contain antioxidants, vitamins and minerals, has a lower glycemic level than refined sugar, is 100% natural – nothing is added and the only thing removed is some of its water content. So, while you shouldn’t add maple syrup to your diet for its nutritive value, it may be a better choice than most other sweeteners.

Why Bother?

You may not want all the bother of making your own maple syrup. After all, it’s pretty time-consuming and, depending on your heat source, not worth it financially. But there are other values to consider. For one, after several cooped-up winter months, some bracing sap-collecting and syrup-making activity gets the blood running through those veins again.

It’s a great learning activity for children, mixing science, math, ecology, and more. And it will most certainly make you appreciate every drop of pure maple syrup you ever put in your mouth, homemade or not. It’s an excellent family activity that’s bound to make lasting memories—children of almost any age can participate in at least some part of the process. And won’t they have fun telling their own children about “that time way back when.”

While you can put a fair amount of expense into making maple syrup, you can also do it on a shoestring, using nothing more than hand-made spiles, a few milk jugs, and an open fire.

Isn’t it at least worth a try?

Carole Coates is a gardener and food preservationist, family archivist, essayist, poet, photographer, modern homesteader. You can follow her Mother Earth News blog posts by following this link. You can also find Carole at Living On the Diagonal where she shares her take on life, including modern homesteading, food preparation and preservation, and travel as well random thoughts and reflections, personal essays, poetry, and photography.


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