The ideal time to harvest birch sap is between March and early May. The harvest period often extends over one to two weeks. Once the leaf buds swell, hardly any sap flows from the roots through the trunk.
Birch sap is best tapped in early spring
How to harvest birch sap:
- drilling: Sap exit through a hole in the trunk
- knock off: Fresh breaks on branches exude water
- To squeeze: succulent foliage releases plant sap when crushed
drilling
Cuts made diagonally from below at a low trunk height result in a small bark injury, which runs through the bark and cambium into the sapwood. The birch water escapes from this wound and is channeled into a collecting vessel with the help of a straw or a piece of wood. Since this variant is not harmless, you should resort to more gentle measures.
driven
With this so-called trunk method, you run the risk of damaging the tree. If the tree loses an excessive amount of liquid, it no longer has enough energy for the development of the leaves and flowers. Healthy and resilient trees usually tolerate the method without any problems, unless it is carried out on the same trunk every year in a row.
Further dangers arise from the penetration of fungi or insects into the wound. Potential pathogens and pathogens are flushed out by the escaping juice. If the wounds are closed with cork or resin, this cleaning cannot take place, resulting in wood rot.
knock off
The branch method is the safest way to harvest small amounts of birch sap. Branch breaks occur in nature due to wild animals and natural phenomena and usually do not cause much damage. Cut a branch about 1/4 inch in diameter so you can stick the tip in a bottle. Tie the jar tight and wait for the flow of juice to subside. The birch sap will keep in the fridge for a few days.
To squeeze
This variant occupies a special position because it is not used to obtain the actual birch water. The juice differs in color and taste. If you collect the juicy leaves, then press them and filter off parts of the plant, you will get a greenish to yellowish liquid. The sap of the birch tastes bitter due to the tannins it contains.