It’s birch sap season, the forest’s spring tonic

Editor’s note: This article has been updated to clarify the average sugar content of maple trees.

Tapping birch for sap, and then using the tree’s sugary goodness to brew wine, beer, tonics and vinegar, is a northern spring tradition of the boreal forest ranging from Ukraine to Finland to Siberia right to our own backyard. Here in Homer, we have plentiful birch trees to tap and make a variety of beverages using their mineral rich sap.

Right now is the time: mid April, when temperatures during the day warm to the 40-50s and the nights dip below freezing. It’s the fluctuation of temperatures that affects the flow of the sap; rising temperatures produce pressure within the tree, causing sap to flow. At night, when temperatures fall below freezing, the tree pulls water up through the roots, replenishing the sap. This cycle is continues until the trees start to sprout buds.

Birch sap season symbolizes the end of winter dormancy and the beginning of spring. As one of the first plants to sprout new leaves after a long winter, birch represents renewal in Celtic mythology. Called “White Lady of the Woods.” birch trees are pioneer species of Northern lands, rapidly colonizing ground recently covered in glaciers. Because they sprout fresh green leaves in early spring before other trees, just as the first thaw begins, birch has long been associated with purification and new beginnings.

In countries like Latvia, they traditionally celebrate the end of their long Northern winter with a birch sap tonic. Sugary sweetness, hard to come by locally, harkened the onset of spring and was reason for celebration. Much the same, to celebrate spring, Homer birches could nourish with their sap.

In its short Alaskan season, birch sap rises from the roots, gathering and collecting nutrients, trace elements, vitamins, and minerals from the soil, and travels up the tree’s cambium to feed the new leaves. It flows in the tree’s budding state when leaves are forming, so it has a season of around two to three weeks (afterwards, leaves use photosynthesis for food).

Sap is leaf food, the life force of the tree. To conserve resources when losing their leaves in the dwindling light of fall, birch trees store important nutrients in their roots over the winter. In the spring, the sap is used to transport these nutrients back up to where the new leaves develop. As it flows through a part of the outer tree trunk called sapwood, the sap delivers water and nutrients throughout the tree. Tapping birch captures sap it on its journey to nourish the budding leaves.

Birch sap can be boiled down into syrup, much as maple sap. It has a 1-2 percent sugar content, compared to maple’s average of 2 percent sweetness, so 100 gallons of birch sap are needed for 1 gallon of syrup, which has a sweet, slightly balsam taste. Instead of simmering it down into syrup, which is labor intensive, the sap can be used to make beverages like wine or tonics. The sugar content of maples varies depending on temperature, tree location and a variety of other factors.

Whether you make kombucha, wine or vinegar, the sap produces a high quality drink. Aqua vitae —- water of life — it’s been called. It’s known as an excellent detoxification due to its high vitamin C and mineral content. From its origins in the roots and soil, trace elements imbue the sap with a subterranean mineral nutrition. Its healing and antioxidant properties have been recorded in medical journals from Japan, Korea, China, Finland and Russia for curing ailments from hypertension to gastritis.

Have a birch in your backyard and want to try tapping? It can be done homemade on the cheap.

First you must get a spigot, or “spiel,” which be bought at farm supply stores, or make one out of polychlorinate vinyl (PVC) piping. Cut PVC into widths of about 8 inches, with a small square cut-out at one end. Using a drill with a 7/16-inch drill bit, drill about 2 inches into a birch tree at a 30 degree downward facing angle; it’s important not to go too far. Hammer or twist in thespiel, then set a collecting container. Depending on sap flow, within a few minute to a few hours, clear liquid starts to gather.

It can be drunk straight from the tree as an antioxidant-rich forest drink. The sap can be flavored with fruit like blueberries or raspberries and left to ferment for a short time for kombucha, or longer for wine. If it’s left to ferment long enough it will turn into birch sap vinegar.

Bring the sap, blueberries and sugar to a boil, remove from the heat and stir until the sugar has fully dissolved. Allow to cool to room temperature then sprinkle the yeast on. Cover to ferment.

The minerals stay in the drink. The product, depending on the flavors added and how long it’s left to ferment, will be slightly tangy, slightly aromatic, and slightly alcoholic — an arboreal elixir.

Tapping birch is a ritual of seasonality. Historically, the sugar in birch sap is one of the first carbohydrates that people in the true north of Siberia and Russia could harvest in the spring. Available before any other food from the new growing season appeared, sap itself is a perfect metaphor for celebrating the onset of spring.

Connecting to nature through food, whether gathering mushrooms or foraging for nuts, gives a little nudging awake of those old, primal impulses lingering in our brain stems. We are, after all, Pleistocene brains walking around with cell phones. To forage through the seasons is to participate in as ancient an act as we can in our genetic human lineage.

Fermentation is similar. We discovered fermentation a long time ago, and it’s been intoxicating us with its mystery every since. The impossible alchemy of wine out of blueberries and birch sap is like playing with small microbial gods.

To forage and ferment is to add to our modern experience, make it more rich, incorporate the environment more fully into our food, and in that way, be more full ourselves in our ecological expression. Not to mention, it’s delicious.

The birch sap wine is semi-sweet and tangy. It has a woodsy, verging-on-bitter, nostalgic flavor that tastes like the past — sorghum, sarsaparilla, hyssop, horehound. A sparkling, mineral rich, probiotic tonic; it tastes like health. Cheers, brother birch.