In the _Magazine of Domestic Economy_ it is said that when yeast has become sour, and even slightly putrid, it may be recovered by adding a tea-spoonful of flour, the same of moist sugar, a pinch of salt, and a little warm water: this is to be stirred together and left to ferment for half an hour. I have never tried this, but it is very nearly the same as the receipt I have given above. The yeast from home-brewed beer is very apt to be bitter; but it is said that this may be cured by pouring it through a sieve containing about a pint of bran. 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 be kept 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 out carefully, leaving a brown sediment at the bottom. _The best way of keeping yeast_ is to hang it up in a cabbage net, so as to let it dry with the air about it on all sides. This is the way the Germans prepare their solid yeast, which is now so much used in London. _When bread is to be made_, the necessary quantity of flour is put into a kneading trough, or into a deep-glazed earthenware pan, and a round hole is made in the centre for the yeast and water, which is slightly mixed with the surrounding flour, so as to form a light batter, and over this is strewed enough dry flour to cover it. I remember, when I was a child in my father's house, I have often watched the cook perform this operation (which I now find is called setting the sponge); and I always used to see her, when she had done, make a cross in the flour sprinkled over the batter, without which she declared the bread would never rise. As soon as the sponge is set, the earthenware pan is placed before the fire, and a linen cloth laid over it. In a short time the sponge begins to rise, and forms cracks in the covering of flour. More water is then added, heated to about the warmth of new milk, and salt is scattered over the flour, which gradually mixes with the water, kneading it well with the hands so as to form a fine compact dough. Some dry flour is then laid under it, and sprinkled over it; and the dough, being again covered with a cloth, is left to ferment, which, if the yeast were good, it does in about an hour, sufficiently to allow the dough to be made into loaves of bread.