In spring, as a tree awakens from its dormant winter state, water and nutrients begin to pump through the sapwood. These nutrients are sent to the buds in the form of sap, enabling them to unfurl and thus begginning the process of new growth for that year. At this time, there are some species of tree that can be tapped for this sap, giving us a delicious and highly nutritious drink that can be made in to a variety of other tasty substances such as syrup and even wine and in our case, beer. Probably the most well known use of tree sap is maple syrup but birch also produces an abundance of sweet sap that can be easily collected without damaging the tree.
How to tap a tree:
There are 2 ways to do this and both should be done first thing in the morning and collected later that evening as the temperature cools. The first and easiest way is to break a small branch and hang your receptacle from it to collect the flow of sap (as in the first picture below). You will see it start almost immediately after you have made the break. The second is to drill a small hole in the tree around waist height from the ground and hammer in a funnel down which the sap can flow into your pot. The method you use may depend on if there are branches at an easily accessible height or not.
It's important to note that your tree should be at least 30cm in diameter indicating that it is mature and can handle being tapped. Younger trees may not and you could end up killing them, so do be mindful of this.
Once you have collected enough sap (you'll need around 5 litres to make beer, so may need to tap more than one tree over a few days) if you used the funnel method, be sure to plug the drill hole with a piece of wood the same length and diameter as the hole. This will prevent the tree from becoming infected or bleeding to death. Keep your collected liquid refrigerated until you are ready to use it. Either drink it as it is, or have a go at our birch beer recipe below.
How to make Birch Sap Beer (we originally followed a recipe by Andy Hamilton)
You will need:
5 litres of sap
3 large handfuls of birch twigs cut up into 10cm lengths
1.25 kg honey
Activated champagne yeast (1 sachet)
Boil the sap for about 10 minutes and then add the honey and stir until it is mixed into the liquid. Add the birch twigs and then let the mixture cool down. Once at room temperature strain the liquid into a fermentation bin. Leave for about 7 days until it is fully fermented. Prepare the bottles you will use to store the beer by adding around half a teaspoon of sugar to each and fill with the fermented liquid. Leave for 2 weeks before drinking. Be warned - ours was quite explosive, so be sure to open it outside!
Make sure you let us know if you try this, we'd love to see your pictures. Enjoy!