Birch Sap: fresh or fermented? It's awesome no matter what

Birch Sap: fresh or fermented? It's awesome no matter what

There are so many great things to do with birch sap. And so many great things it can do for you.

When the winter snow has just melted and the first hints of spring start to appear, nature offers us a few weeks to enjoy one of its gifts: the sap of the birch tree.  Its smooth, silky sap with that very subtle, but unmistakable sweetness tastes like the best water on earth (at least to me).  Perhaps this is due to that back-to-nature, living-off-the-land feeling that you get as you watch this crystal clear "water" come out of the tree and then drink it.  And along with the taste, it's packed with a remarkable amount of nutrients. 

Birch water (sap) has become quite trendy over the past few years, but it's been drunk as a health tonic in places like Scandinavia, the Baltic countries, and Russia for centuries.  Traditionally, it has been used for medicinal purposes as well as a nutritional supplement.  The sap is diuretic and has been claimed to have detoxifying, cleansing, and anti-inflammatory properties.  It's been used to treat ailments from kidney stones to lung diseases to arthritis.  According to a good guide by the University of Alaska Fairbanks, birch sap contains fructose, glucose, a slight amount of sucrose, fruit acids, amino acids, vitamin C, potassium, calcium, phosphorus, magnesium, manganese, zinc, sodium, and iron along with malic, phosphoric, succinic, and citric acids.

Birch water (sap) is a popular drink in eastern Europe

If you live in an area with birch trees (which includes the northern part of the northern hemisphere), you can easily tap the trees yourself.  If you don't have any birch around you, it is becoming more widely available on the market.  Sibberi and Sealand BIRK (which I've tried in Norway) both produce pure birch water for purchase in the UK and other parts of Europe as well as the US.  As Sibberi points out, birch water has "only 5 kcal for 100ml. It is 4 times less than your typical Coconut Water (it is a bit like a diet Coconut water)".

But I still prefer to get birch water directly from the tree.  And I can highly recommend trying it to anyone else who can.  But how do you do it?  And what do you do with it?  Here's a simple guide:

How do I find the right tree?

First of all, you need to wait until temperatures start getting above freezing (usually end of February to early April depending on where you are and how cold the winter has been).  Although there are a few different species of birch, they all can be used and are pretty easy to identify by their white/grey bark.  The most common of these are Betula alba (white birch), Betula pendula (silver birch).  You will want to select trees that are no less than around 10 inches (25 cm) in diameter and look healthy.  Trees with a lot of branches will have the best sap flow.   

Silver birch trees in Finland

How do I get the sap out?

It's not a science.  Beyond where and how deep to drill the hole, there are countless variations on the actual collection method.  First, some basic equipment is required: a drill with a 12mm (7/16'') bit and a container/bottle or plastic bag to collect the sap.  If you use a bottle, you can attach it to the tree with string or tape or you can insert tubing into the hole in the tree and run it down into a bottle on the ground.  Once you have figured out how you are going to do this, select a point about 1 meter (3 ft) from the base of the tree and drill at an upward angle (around 30 degrees) 3-4 cm into the tree.  You should see sap (which looks like water) flowing out of the hole almost immediately. 

Next, fit the hole with a tap (as shown - or insert a piece of a branch with a channel/grove in it) or insert some food grade tubing.  When the sap is running out of the tap or tube, position the container or bag in a way which collects the runoff and wait.  If you are using an open container, you might want to cover it as it does attract insects.  It should take several hours up to an entire day to collect 4 liters (~1 gallon).   You can continue to collect the sap until the flow slows or starts turning cloudy, which means the window of opportunity has closed (the season lasts 2-3 weeks).

Let it flow!  Let it flow!

Or you can do it this way

Will this hurt the tree?

As long as it's done correctly and the tree is not tapped more than once in season, then the tree will most likely not be harmed.  There doesn't yet seem to be a consensus on what to do after sap collection is finished: fill the hole with a piece of wood or resin - or leave it unplugged.  Some people think that plugging it creates a barrier to infection; others think that if the hole is left unplugged, the tree will rely more on it's own immune system and become stronger.     

What do I do with the sap?

Now comes the best part: using the sap.  First, taste it right from the tree.  You might be surprised at first that it tastes like water, but after you get over that fact, you will notice the subtle differences (silkiness, freshness, slight sweetness) which make it so delicious.  

Here are a few things you can do with birch sap:

1) Drink it fresh - the sap doesn't stay fresh for long (it will start fermenting on its own after a few days in the refrigerator - or sooner if left out at room temperature), so drink it quickly if you want it fresh. 

2) Make an infusion - I like fresh ginger and turmeric infusions.  Using birch sap instead of water makes this an even more delightful health drink!

This is awesome.  Letting it ferment would also be awesome.  
3) Let it ferment naturally - you can bottle it with a few raisins (to promote fermentation) and leave it at room temperature for a couple of days.  This will create a sour tonic which some consider refreshing and, due to the probiotic properties that will develop, could possibly be even more beneficial than drinking it fresh.  You can also add herbs, spices, or fruit, for example to enhance the flavor.

4) Make birch wine (or some form of alcoholic birch beverage) - There are countless variations on this.  The basic concept is that you boil it, add sugar or honey, then put it in a fermenter and add yeast (and possibly some with some raisins, citric acid, and/or yeast nutrient).  Let it ferment for a few weeks, then either transfer it to another fermenter or bottles to age for at least several months (you can also drink it young, but with if the alcohol content is high, ageing will likely improve it dramatically).

I am making a birch wine (actually mead as I used honey instead of sugar) this year using Ben Law's recipe:

1 gallon birch sap

2 lemons

200g raisins

1 kg honey

yeast (I used mead yeast, but champagne yeast would work well too)

Squeeze lemons. Add a little grated zest to the birch sap and boil for 20 minutes. Pour sap on to sugar or honey and raisins. Stir until the sugar or honey is dissolved. When lukewarm add yeast, cover with a cloth and leave in the fermenting bin until fermentation has slowed down. Then strain into a demijohn. Top up with water as necessary and fit an air lock. Should be ready to drink by late summer. 
Birch sap mead: ageing works wonders 

4) Make syrup - Birch syrup is relatively difficult to make at home because the sugar content of birch sap is very low (much lower than maple sap) and the sugar caramelizes (and burns) when heated too much.  So you need a lot of sap to get a worthwhile amount of syrup an you need to monitor it to make sure it doesn't boil too hard.  Estimate one liter of syrup from 100 liters of sap!  Industrial producers use reverse osmosis equipment to make this process easier and avoid burning the sugar.  I've not made or tasted birch syrup, but it's apparently very good.  Here's an interesting video with more details:

And here's a video on tapping the trees:

If you've never tried birch sap, give it a try this year!  If you´re already tapping, I'd love to hear what you do with the sap. 

Image Attribution: Main image and birch trees in Finland have been released into public domain; bottle of birch water by Fox89 under Creative Commons Attribution-ShareAlike 3.0 Unported; all other images are author's own


Really Interesting, David !
Respond 1 2.Apr 16:24

Al McLauchlan

Great Article! We produce birch syrup in Northern Manitoba. We tap about 1500 trees and our season will begin very shortly. Cant wait to get out in the bush and drink some fresh sap!
Respond 2 9.Apr 18:15


Thank you! Happy tapping! Would love to try your syrup.
0 9.Apr 18:18


I believe I missed our window of opportunity here in PA. I'll gave to scout out some birch trees for future use. I'd love to try this, if only once. :)
Respond 1 25.Apr 14:06


Yeah, I would imagine that the season is well over in PA. But definitely give it a try next year. It's a great activity to do every once in a while.
0 25.Apr 14:33
Write an article