Fermented birch sap is one of the best natural juices we have ever enjoyed. In Eastern Europe, as spring arrives, the beauty of nature is broken by bottles and buckets of different sizes hanging from branches and tree trunks, mainly in birch and maple trees.
The bottles are slowly filled with the clear, slightly sweet, watery birch or maple sap. The juice is wonderful to drink fresh, though some like it better fermented. Fermented birch juice is tangy and very refreshing when served cold. The juice will taste slightly sweeter after a cold winter.
During a few weeks in spring throngs of fans flock to forests to get their annual share of birch juice. But you can also buy it in the market and in shops. We usually get plenty of fresh juice and drink it daily for few weeks. But we also prepare fermented birch sap of different kinds.
Fermented birch sap surprisingly tasty
If you have never tasted fermented birch juice, you might get a pleasant surprise when tasting it. While fresh birch sap is slightly sweet, fermented sap is crisply dry, tangy and a little sparkling.
Some years ago a farmer producing birch juice in Latvia appeared at the World Organic Food fair in Germany. He received so many orders that he had to turn away most of them as he was short on birch juice. People were amazed at how fresh and pure the taste is, especially if they have only previously encountered the pasteurized, sweetened versions of birch juice that are sold in some countries.
When my wife and I first tried birch sap, we immediately fell in love with it. It feels very refreshing to drink. Fresh sap should be consumed fairly quickly. but when fermented, birch sap can be stored much longer.
Properties of birch sap
Interestingly, fresh birch juice has a similar chemical profile as coconut water. The tree sap contains a number of micronutrients.
- Saponins (phytochemicals)
- Phytohormones
- Sugars (xylitol)
- Essential oils
- Amino acids
- Phytoncides
- Proteins
- Minerals
- Enzymes
Birch sap has traditionally been used for its purifying and diuretic properties. The sap is said to promote the elimination of waste from the body as food additives, coloring, uric acid, phosphate and many other substances. Therefore, birch sap has been used for kidney stones, arthritis, inflammatory conditions and to promote clear supple skin.
Birch sap is structured water
Birch sap contains structure water which might explain the benefits. Studies show that structured water help cleanse out toxins and waste, regulate weight, strengthened immunity, supply cells with organic acids, stimulate metabolism, rinse salt precipitation from bone joints and perform many other healing functions.
Research into birch sap’s anti-aging properties at the University of Latvia has prompted some companies to launch a line of birch sap products. Studies on birch juice show that it may stimulate the growth of dermal and epidermal cells and help delay cell ageing. However, for a stronger effect on the skin, a more concentrated birch sap is used in studies.
It seems that birch sap might rejuvenate and protect skin cells from oxidative stress, including ultraviolet rays, environmental pollution and consequences caused by inflammation.
As with most fermented food, also fermented birch sap may have increased benefits compared to fresh sap. Fermenting tree sap was originally a simple way to preserve the juice for a longer time. During fermentation, several new compounds are created in the juice boosting its potency. Fermentation also makes it easier for the body to assimilate the many micro-nutrients present in the juice.
How to ferment birch sap
Fresh birch sap contains natural, beneficial microorganisms that will start to grow within 2-5 days at room temperature. The clear, fresh sap turns cloudy after 2-5 days at room temperature. The sap will slowly turn slightly tangy within a week. The fermented juice can be enjoyed right away or used as a base to produce a fizzier drink.
Fermented birch sap recipe
This is one way to produce a fizzier fermented birch sap. Adding sugar promotes more bubbles as more bacteria produce gas.
- Pour fresh (or slightly fermented) birch sap into a clean bottle that can be tightly closed
- 1 teaspoon sugar per quart of juice
- A few raisins (support fermentation)
- 1 clove (prevents mold)
- 1 small black currant branch
- Leave the birch sap to ferment at room temperature; in 5-7 days it should turn slightly tangy.
- Store in a cool place for another 15-20 days.
Optional: Try a different taste in each bottle, for example peppermint (a clear winner), lemon, juniper berries, ginger.
Sparkling birch sap
If you want more bubbles like a sparkling wine, then add more sugar.
Ingredients:
- 1 quart fresh (or already slightly fermented) birch sap
- 2-3 teaspoons sugar
- 4-5 raisins
- Citric acid (or a small piece organic lemon)
Preparation: Add sugar, raisins, and a little citric acid to each bottle. Fill the empty wine or champagne bottles with fresh birch sap until the neck, i.e. not completely full. Put the cork on and tighten the cork with a string to hold it in place when the pressure in the bottle increases. After 15-20 days or longer, it should be ready to drink.
Drinking fermented birch sap
Most experts say fresh birch sap can be treated as water, so it’s hard to overdose. The sugar contents of fresh birch sap are not very high, so it’s safe to drink for most people.
Fresh and fermented birch sap are both great. But a bottle of well-fermented birch sap is hard to resist during warm summer days.
Reference: University of Latvia study
Eleonora Z. says
Good evening,
thank you for this article! Very impressive and informative!
I would be pleased if you could specify, which exact University of Latvia made the experiments/conclusions.
I study Food-Development and Health and working on my graduated project now about the Birch Sap, it will be really helpful for me, because there are not so many reliable studies with reliable evidences about this subject.
Best,
Eleonora Z.
Ken Silvers says
Hello Eleonora.
Nice to hear you like the post. This research on birch sap and in vitro testing was done in the Laboratory of Bioanalytical and Biodosimetry Methods, University of Latvia. For a more detailed report on the effects of birch sap on skin cells, try this link.
All the best with your studies.
Jim Wass says
I’m tapping for birch sap at the moment and trying your suggestions.ihave not managed to clear the naturally fermented samples which have been in the fridge for nine days now.They taste exactly as you described however. How long will they be safe to drink?
Also have two gallons of wine now in demijohns which are fermenting very strong and steady, and three more gallons to be started later today.
I will report back later with triumphs and disasters!
Ken Silvers says
Hello Jim.
Glad to hear about your birch sap. Cool that you’re making wine! That’s something I’ve yet to try. About your question. I’ve asked several specialists and they all say that birch sap can be saved for months if stored properly, meaning in a cool place. When the sap is fermented, the good bacteria are basically in control, so little risk that mold will ruin it. Fermented sap sometimes have a funny taste, but this they say is normal.
Jim wass says
Hi Ken,
Well now its mid July,and summer arrived yesterday here in England.
When I wrote last time we were still tapping for birch sap in the woods of our beautiful Peak District.We collected about twelve gallons by the time the buds were just about to open.A little later,when the leaves were still very young and very fresh,we collected them too to make tea.
We made nine gallons of birch sap wine all told,using a few variations-some with oranges,some with lemons,raisins,and dates.
We have sampled a few already and have three gallons still fermenting out in demijohns.
Its all very acceptable and should mature to be very good dry wine if my friends can develop the virtues of patience and temperance!
The other three gallons we either drank simply fresh or fermented.
I’m afraid I didn’t manage to produce a sparkle or even a a faint fizz in the latter,but it did keep very well in the fridge-two bottles lasting til only two weeks ago,and tasted very well indeed.So thank you so much for your assurances on its keeping qualities.
My only regret now is that we didn’t collect much more,because it really is so wonderfully good,and it has drawn me into fermenting that appears to be becoming a lifestyle.
I have actually shed about fifteen kilos so far and feel much healthier altogether already.
Thank you so much.I appreciateyour site a great deal.
Kindest regards,jim
Ken Silvers says
Hello Jim
Very nice to hear about your great quantity of birch sap you collected. And the wine sounds very exciting.
I have also at times experienced difficulties preparing sparkling birch juice. A few times it turned out extremely good, almost as bubbly as soda water. Other times it took a bit longer for bubbles to develop, two weeks or so.
I know a specialist who always seems to succeed. I plan to talk to him to learn his secret to create perfect fizzy birch juice.
I have heard positive reports from others about the health benefits of drinking birch sap. Great that it helped you lose Wright. And you are right, it becomes a lifestyle, and a good one at that.
Jim wass says
Thanks Ken,look forward to hearing back from you when you find the time.
I’m also fermenting water kefir grains,and finding the same problems with the fizz.Only once have I managed a soda-like drink,and often something a little flat,sometimes in between the two. It seems to have become more problematic since splitting the grains despite nursing both jars for some days afterwards.
Any thoughts?
Ken Silvers says
Water kefir is something I’ve yet to try. I do milk kefir all the time from raw milk, love it. But I will give water kefir a try as soon as I can.
Louise says
Hello, Ken,
This is the first time that we collect birch sap. I had no idea it could be fermented. After fermentation, you explain to keep it in a ‘cool’ place. Do you mean a refrigerator? What degree is ‘cool’?
Thanx so much for your post!!
Louise
Ken Silvers says
Hello Louise.
Birch sap usually starts to ferement naturally only after a few days in room temmperature. Many people add a little sugar, a few raisins and perhaps a mint leaf or small piece of lemon peel. This promotes fermentation and adds a nice taste. Then ferment the bottled sap for 3-5 days in room temperature. After that it’s recommended to keep the bottles in a cool place (like a fridge or cellar). Keeping them cool helpt preserve the freshness. Otherwise the sap might become too tangy and develp a taste of yeast (which some people enjoy).
Grace says
We made 3-4 gallons in a 15 gallon pot (started with that much birch water). We put raisins in it at the end of the boil, and now, less than a week later, we have mold on top. We used a dry yeast. Can we salvage it?
Ken Silvers says
Hello Grace.
Sorry to hear about your batch. If you want to make fermented birch juice then heating it will for sure ruin the batch. Birch sap is feremented without heating it to preserve the bacteria naturally present. The same with adding yeast, that is not needed but can introduce microorganisms that might ruin the batch. Mold is bad, most often ir ruins the whole batch.
However, if you want to make a birch syrup, then you can boild the sap to reduce it and then add sugar. Or perhaps you try to make birch wine.
Here is one wine recipe on birch sap:
– 4.5 quarts of birch sap
– 200 ml white grape juice concentrate
– Juice from two lemons
– 1.2 kg (2.4 pounds) white sugar
– White wine yeast
– Yeast nutrient
Heat the sap in a pan with the lid on (do not boil!) for 15-20 minutes. Take off the heat and dissolve the sugar in the juice. Cover the pan and let it cool. Transfer the juice to a fermentation bucket and add the lemon juice, grape juice concentrate, yeast and yeast nutrients. Keep the bucket covered for five days. Transfer to a demi-john, fit the bubble-trap and leave for about two months. Bottle when it is all nice and clear. You have to be careful to use sterile tool as it easily goes bad (like mold).