Pasteur Brewing Louis Pasteur – Science, Health, and Brewing The liquor of the birch-tree is to be obtained in the month of March, when the sap begins to ascend. One foot from the ground bore a hole in each tree, large enough to admit a faucet, and set a vessel under; the liquor will run for two or three days without hurting the tree. Having obtained a sufficient quantity, stop the holes with pegs. To each gallon of the liquor add one quart of honey, or two and one-half pounds of sugar. Boil together one hour, stirring it well. A few cloves may be added for flavor, or the rind of a lemon or two; and by all means one ounce of hops to four and one-half gallons of wine.
Work it with yeast, tun, and refine with isinglass. Two months after making, it may be drawn off and bottled, and in two months more will be fit for use, but will improve by keeping.
