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Irish Potato Yeast
1 quart of potatoes, boiled and mashed fine. 1 teaspoonful of salt. 1/2 teacup of sugar.
Put two cups of flour in a bowl, and pour over it three cups of strong hop-water, scalding hot, and stir it briskly.
Then put all the ingredients in a jar together, and when cool enough, add a cup of yeast, or leaven.
Set it by the fire to rise.
It will be ready for use in five or six hours.--Mrs. E. Another Recipe for Yeast. 12 large potatoes, boiled and mashed fine. 1 teacup of brown sugar. 1 teacup of salt. 1 gallon of hop tea.
Mix the ingredients well, and when milk-warm, add a pint of yeast. Set it in a warm place to rise. Put one teacupful of this yeast, when risen, to two quarts of flour.--Mrs. Dr. S.
Yeast that Never Fails.
Boil twelve potatoes in four quarts of water till reduced to three quarts. Then take out and mash the potatoes, and throw into the water three handfuls of hops.
When the hops have boiled to a good tea, strain the water over the potatoes, a small quantity at a time, mixing them well together. Add one teacup of brown sugar. 1 teacup of salt. 1 tablespoonful of ground ginger. When milk-warm, add yeast of the same sort to make it rise. Put it in bottles, or a jug, leaving it uncorked for a day. Set it in a cool place. Put two large tablespoonfuls of it to a quart of flour, and when making up, boil a potato and mix with it.
This yeast never sours, and is good as long as it lasts.--Mrs. A. F.
Three versions of the same thing: a liquid barm kept alive on potato starch and preserved with hops, the standard household leaven before packaged yeast. None of the three starts from nothing — each requires a cup or a pint of existing yeast to seed it.
- You need a starter to start"Add a cup of yeast, or leaven" and "add yeast of the same sort" assume a jar of the previous batch on hand. Without it these are sugar-and-potato broths that will catch whatever is in the air. Seed with an active sourdough starter or a packet of commercial yeast slurried in warm water if you want a predictable result.
- Hop-waterHop tea is made by boiling dried hop flowers (about a small handful, 1/4 to 1/2 oz, per quart) for ten to fifteen minutes and straining. Any bittering hop from a brewing supplier works. The hops are not there for flavour but for their antibacterial resins, which hold off the souring organisms that spoil a wet barm.
- Teacup and quartA teacup in this book is roughly a cup, 8 fl oz, though period teacups ran smaller and the measure is genuinely loose. "1 quart of potatoes" is ambiguous: it may mean a quart measure of cut raw potatoes (about 1 1/2 lb) or a quart of the mash. Twelve large potatoes is somewhere in the region of 4 to 6 lb.
- Milk-warmBlood heat, 95-100F. This is the hinge: the scalding hop-water must be down to this range before the seed yeast goes in, or you kill it. "Set it by the fire to rise" means a warm corner around 75-85F, not against the stove.
- That teacup of saltA full cup of salt to a gallon of liquid is a heavy dose and will slow fermentation markedly; salt at that level acts as a preservative as much as a seasoning. The first recipe's single teaspoon behaves quite differently, and that recipe — also seeded with a full cup of yeast — is the one given as ready in five or six hours.
- Do not cork it tightThe instruction to leave the bottles uncorked for a day is the important part, and even after that a fully sealed glass bottle of active barm can build enough pressure to burst. Keep it under a cloth or a loose lid, and refrigerate rather than trusting the cool cellar the recipe assumes.
- Using it in breadThe proportions given — a teacup to two quarts of flour, or two tablespoons to a quart — are a wet leaven, so count the liquid as part of the dough's water. Expect a long, slow rise measured in hours rather than the 45 minutes of a modern packet, and judge by the dough rather than the clock.
- Keeping itIt stays usable while it smells yeasty and beery; once it turns sharply sour, vinegary or grows anything coloured, discard it and start again from a fresh seed.
Before compressed yeast became widely available in American kitchens in the last quarter of the nineteenth century, many households that baked bread kept a leaven going, and hop-and-potato barm was one common Southern and Midwestern form. The potato supplied starch the yeast could work on, the sugar gave it a fast start, and the hops — borrowed straight from brewing practice, where their preservative effect had been understood for centuries — suppressed the lactic bacteria that turned a wet barm sour within days. Housekeeping in Old Virginia (1878/79) was compiled by Marion Cabell Tyree from contributions credited by initials, which is why the same task appears three times over with three different sets of proportions; the book preserves the variation rather than resolving it. The title of the third, "Yeast that Never Fails," is the sort of claim that only gets made about a process everyone knew could fail, and the recipe calls for heavy salt and ginger.