The time is nearly upon us for the annual collection of vernal birch sap.
Birch sap is a clear, very slightly sweet sap (only about 1-2% sugar) that is collected after the winter thaws and just before bud break. Its a window that is no more than a month, often there are two weeks within this that is an optimal time. Aswell as some sugars the sap has various minerals, enzymes and amino acids and proteins. It is traditionally collected in northern climes: russia, northern europe, china and is drunk fresh, fermented or boiled down to make a syrup (a bit like maple syrup). It has many claimed health benefits. I either make ice cubes out of it, drink it fresh (it only lasts a couple of days before it spoils) or ferment it (old english recipe below) to make beer!
“To every Gallon of Birch-water put a quart of Honey, well stirr’d together; then boil it almost an hour with a few Cloves, and a little Limon-peel, keeping it well scumm’d. When it is sufficiently boil’d, and become cold, add to it three or four Spoonfuls of good Ale to make it work…and when the Test begins to settle, bottle it up . . . it is gentle, and very harmless in operation within the body, and exceedingly sharpens the Appetite, being drunk ante pastum.”
A mature tree can yield between 2-3 gallons a day. Best not overdo it though – the tree needs this, so after you have drawn off a single amount then bung up the hole properly with clean bit of wood afterwards so it does not continue to weep and damage the tree.
Here, below are a few techniques for getting the sap. In fact there are many ways, I find the ones which don’t involve drilling into the tree the best though. This I feel is less invasive – these come towards the end.
Demijohn, plastic pipe and auger.
Auger, billy can and an elder ‘gutter’
This step-by step is on a sycamore (which also has an edible sap), but its the same process for birch. – click on image to enlarge it.
Knife and billy-can
Stick and billy-can
Plastic bottle and wood wedge
Bottle and branch