Measure 4 quarts of finely cut twigs of sweet birch into the bottom of a 5 gallon crock.
In a large kettle, stir 1 gallon of honey into 4 gallons birch sap and boil for 10 minutes, then pour over the chopped twigs. When cool, strain to remove the twigs and return to the crock.
Spread 1 cake of soft yeast on a slice of toasted rye bread and float on top of the beer. Cover with a cloth and let ferment until the cloudiness just starts to settle, about a week but it depends somewhat on the temperature.
Bottle the beer and cap tightly. Store in a dark place and serve it cold after the weather gets hot. It should stand in the bottles for about 3 months before using. If opened too soon, it will foam all over and pop worse than champagne.
THIS IS NOT A DRINK FOR CHILDREN:
SWEET BIRCH (Betula lenta) also called Black birch, Sweet birch or Cherry birch has fragrant bark and twigs that smells of wintergreen. The sap flows about a month later than maple and much faster than maple. You tap the trees the same as maple but must gather about 3 times as often.
The sap also can be boiled the same as maple but the syrup is much stronger, more like molasses.