No. 3537 — Moscow Kvass from Raspberries and Strawberries
English historical translation of Molokhovets recipe No. 3537 from the 1901 Russian cookbook, retaining original methods and measures.
The author uses a special tub for these delicate berries. Near the bottom, on one side, the tub has a hole about ½ vershok across closed tightly with a wooden peg.
Lay the very cleanest fresh straw on the bottom, first rinsed and thoroughly dried in sunlight, until the straw is about 3 vershoks higher than the outlet. It filters the sediment that soft raspberries and strawberries release in water.
Fill the tub with berries and pour over boiled water. Whenever a bottle of kvass is drawn off, replace it with a bottle of previously boiled, cooled water.
If the kvass is too concentrated, dilute it with water and sweeten only immediately before drinking. When it becomes too weak from repeated replenishment, discard that batch and start a freshly prepared tub.
The tub must stay on ice, packed with ice all around in hot weather and in a cellar in winter. The author warns that freezing spoils the drink.