No directions are here given for making new yeast without old yeast as an ingredient. Therefore in making it be sure that you have good lively yeast to raise it with. Borrow from a reliable neighbor if possible, the first time; and afterwards always save over a cupful of your own to raise the next, as baker's yeast is very apt to be sour.
Do not make more yeast at one time than is given in the receipts, for it will sour if kept too long. It is well to make it fresh every six weeks. Care should be taken to have the mixture of exactly the right temperature when the old yeast is put into that which you are making. It must not be either hot or cold, but between the two. Never stir yeast with anything but a wooden or silver spoon, for an iron one will turn it dark-colored. Set it to rise, covered over, in a decidedly warm place where there is no draught. It should rise rather fast, and on that account it is best to make it in the morning, as the housd is usually warmer through the day-time than at night, If it does not rise sufficiently during the time given in the receipts, stir it up once or twice from the bottom. When it is light enough to bottle, it will have a thick foam on top, and will be bubbly all through. Be sure that the bottles (or jars) are perfectly sweet. They should be scalded while the yeast is rising, and set together in a large pan or waiter, so that if any runs over the top of the bottles (as it may a few hours after, if you get them too full, or if very light) it will not make a mess on the cellar shelf. (Preserve jars or bottles of the size of whiskey bottles are preferable to a jug for keeping yeast, as but one bottle at a time need be uncorked, whereas, with a jug, the whole quantity of yeast is exposed to the air every time any is drawn off.) Stir the yeast rapidly before pouring through a funnel into the bottles, which should only be filled two thirds full. Cork tightly, with perfectly clean corks, and set at once in a cold place.
Every time you want yeast for setting bread, carry your cup or whatever it is to be measured in, to the cellar, and pour out the yeast there, first shaking it hard, till it froths. This is a better plan than to take the yeast to the warm kitchen, where it may sour, if left but so short a time as half an hour. Always stir up the yeast the moment before you put it into the bread. A novice will often be puzzled to tell whether yeast is good or not, on account of the peculiar odor which accompanies any fermentation. It will perhaps seem sour when it is in reality perfectly good. If, however, sour bread is the result, throw away all the remaining yeast, and make fresh; using fresh yeast to set it with. Do not, as some will advise, attempt to make it right by the use of soda. It is too doubtful an experiment, and it is less wasteful to throw away a gallon of yeast than a whole "baking" of bread.
3 large potatoes.
3 pints boiling water.
1 large tablespoonful salt.
1 cupful yeast well shaken.
Peel the potatoes, and put them to soak in cold water till the kettle boils. Then grate one potato, in a large earthen dish, pour over it at once one pint boiling water (to cook the potato) ; grate the next, and pour on the next pint of water; do the same with the third. (If you grate them all, before pouring on the water, they may turn dark.) Stir quickly with a wooden or silver spoon. Mix in thoroughly the salt and sugar. Leave it to become lukewarm (not cold). Then put in the yeast, stir it well, and leave to rise in a warm place four or five hours. When light and ready to bottle, it will be covered with a thick foam. Stir it up and bottle it. This is the most quickly and easily made of any kind of yeast and makes delicious bread.
4 pounds potatoes (pared and cut up). 4 quarts water. 1 handful fresh hops. 1 cupful salt.
1 cupful sugar.
1 tablespoonful ginger. 2 yeast-cakes. 4 table spoonfuls tepid water.
Boil the potatoes in three quarts of the water, and pass them through the colander with the water. Boil the hops ten minutes in one quart of water, and strain the water on the potatoes. Add the salt, sugar and ginger. The whole quantity should measure five quarts; if lacking, add tepid water. When lukewarm, add the yeast-cakes, mixed smooth in the four tablespoonfuls water. Keep in a warm place for a day and a night. When light it will be foamy on top. Then bottle, cork, and keep in a cool, dry cellar. It will keep for a number of weeks.
After having made it once, save a cupful to raise the next with, instead of yeast-cakes.
1/2 a corn meal yeast cake. 1 quart tepid water.
Flour to make a thick batter.
In winter, mix the sponge at one or two o'clock; in summer, at four o'clock. In winter, use two thirds (or more) of a yeast cake.
Soak the yeast cake for one hour in a little warm water, enough to cover it. Then add the quart of water, and beat in flour, until, when the batter is poured from the spoon into that which is in the bowl, it will not mix with it, but will lie in drops on the top.
Set in a warm place, covered, to rise for about five hours. It will then be ready to use to set bread. If not wanted at once, it will keep a day or two in a cold place, if covered tight.
This will raise four medium-sized loaves of bread.