Making, Increasing and Keeping Yeast
It may be made by putting a teacupful of split peas into a basin and pouring a pint of boiling water over them. A cloth is then put over the basin, and it is set near the fire to keep warm. In about twelve hours it will begin to ferment, and a kind of scum will rise, which may be used as yeast. This is called Turkish yeast; but a better method is practised by Americans, which is as follows:- Take as much hops as may be held between the thumb and finger, put them with a few slices of apple into a quart of water, and boil the whole for about fifteen minutes or twenty minutes. Then strain the liquid, and when it is lukewarm stir in a little flour with three or four table-spoonfuls of treacle so as to make a thin paste; then set the whole in a warm place, and in a few hours the fermentation will be sufficiently strong to allow enough flour and water to be added to make a proper sponge for bread.
If you have a small quantity of yeast it may be increased in the following manner:- Take one pound of fine flour, and mix it in to the thickness of gruel with boiling water, add half a pound of brown sugar, mixing the whole well together. Then put three tablespoonfuls of yeast into a large vessel, and pour the mixture upon it. It will ferment violently, and the scum which rises to the top will be good yeast, which may be used immediately, or may be preserved for some time in an earthenware vessel covered closely from the air, and kept in a warm dry place.
To keep home-brewed yeast it should be put into a large pan and have three times the quantity of water poured upon it, being well stirred up and then left to settle. The next day the water is to be poured off, and fresh put on, and in this manner it is said that yeast may keep for six weeks. All yeast is best purified before it is used; that is, the yeast should be put into a vessel, and, cold spring water being poured upon it, they should be stirred together and then left to settle. The water is afterwards poured off, and the yeast taken our carefully, leaving the brown sediment at the bottom.
Mrs London, The Lady’s Country Companion, 1845
The Turkish yeast is less labour intensive but the hops one is closer to what we’re used to and the tip for thickening it is very helpful. As for keeping it, finding clean/non-treated spring water can be a mission but purified water should do. It might sound like a lot of work but when it comes down to it, it’s fermentation – like making sauerkraut, kimchi or brewing.