Yeast Before Science: The History of Mother Yeast and How It Was Kept Alive

The Foam Called God-Is-Good

Every man at his still believes the copper does the work, or the fire, or himself. He is wrong on all three counts. The most important, most ignorant and most necessary creature in the whole craft is the yeast. Our grandmothers raised bread with it and our grandfathers raised hell with it, and for two hundred years not one of them had the faintest notion what was doing the work.

For as long as men have made beer, wine, cider and bread they have known one thing and nothing else. Put a little of the old foam into the new sweet liquor, keep it warm, and it comes alive. It heaves, it bubbles, it stinks like a tanner's apron, and three days later the sweet is gone and the strong has come. Nobody knew why. The brewers of Norwich in old England, four hundred years ago, called that foam goddisgoode, which is God-is-good. It may be the only time a churchman and a brewer ever agreed on anything, and they agreed because neither one knew what he was talking about.

Around 1680 a Dutch cloth merchant of Delft named Leeuwenhoek, who ground his own lenses, put a drop of working beer under his glass and saw little round globules floating in it like frog's eggs in a ditch. He was looking straight at the culprit and never knew it was alive. That is like a sheriff looking at me with a jar in each hand and writing down "two lamps." A hundred and fifty years later, around '37, a Frenchman named Cagniard-Latour and the Germans Schwann and Kutzing looked again with better glass and declared that the yeast was alive. It buds, they said, putting out little children from its own side the way a potato puts out eyes, and it eats the sugar and gives off the spirit and the gas.

Liebig's Privy and Pasteur's Flasks

The great chemist of the age, Professor Justus von Liebig, held that fermentation was mere decay, a chemical rot no more alive than rust on a plow. In 1839 he and his friend Wohler printed a joke in their chemistry journal, and I have read a translation of it. They drew the yeast as tiny animals shaped like distilling flasks, which eat the sugar, pass the spirit out of their back ends and let fly the carbonic gas from their bladders. The whole vat, in their telling, is a crowded privy of little beasts pissing whiskey. Having tended bar in Concord in court week, I believe the Professor was describing the Merrimack County bench.

The joke has turned on the joker. These past several years a careful French chemist named Louis Pasteur has been proving with his glass and flasks that the yeast is alive after all, and that when wine or beer goes to vinegar and slime, it is because other little living things got in and spoiled it. The Paris papers say the Emperor himself set him to find out why French wine goes sick, and Pasteur says that if you warm it gently the spoilers die. So the yeast is an animal, or near enough, and it does piss whiskey, near enough. Nothing dead eats that much and complains that loud.

Emptins, Hop Yeast and the Yeast Cake

Out here nobody was reading Liebig. Your grandmother had a crock, and she valued it above her silver spoons, because spoons don't die when the fire goes out. In old New England the stuff was called emptins, from emptyings: the gray sludge from the bottom of the beer or cider barrel, full of the working. Miss Amelia Simmons, in her American Cookery of 1796, the first cookbook any American wrote, calls for emptins to raise her bread. In the same book she calls for pearlash, the refined white potash of wood ashes, to raise her cakes without any yeast at all. Mark that pearlash, because we will meet it again.

Emptins do not keep. Loose yeast left on the shelf goes sour, then pink, then slimy, grows a fur coat and stinks like a dead cat in a rain barrel. The women of these hills worked out two remedies. The first is hop yeast. They found that hops hold back the souring rot, though nobody knew why, and that a hop yeast keeps twice as long as a plain one. Pittsfield housewives grew hops on the woodshed for that reason alone. The second is the yeast cake. Work live, foaming yeast into cornmeal until it is stiff, pat it into cakes the size of a dollar, and dry them slowly in the shade. Keep them away from the stove and out of the sun, because heat kills yeast, and a dead yeast cake is only a bad cracker. Dried properly and hung in a cloth bag from the rafter, a cake will sleep for months. When you crumble it into warm potato water it comes up like Lazarus.

Keeping the Mother Through a Frozen Winter

Cold will not murder your yeast. It only puts it to sleep, like a deputy after dinner. What kills it is freezing hard and thawing over and over, and above all scalding. At Fort Wilkins I keep the mother crock in a niche in the chimney masonry, where the bricks stay as warm as a hen's belly all night. If the fire will drop low, the crock goes into a box of dry sawdust, packed the way the ice men pack ice but in reverse, and on the coldest nights a hot brick wrapped in flannel goes in beside it. Once a week I feed it: a cup of the old into fresh potato water and hop tea with a spoon of molasses. A yeast that is not fed gets tired, and a tired yeast is a sour one. Lastly, I never keep my eggs in one crock. A string of dried cakes hangs from the rafter, and a cup of my mother yeast lives in a neighbor's kitchen.

The worst does come. In January of '63 it came in the shape of Hosea Pettengill of Barnstead, whose own yeast was a sick, slimy thing he had neglected since Polk was President. He pried my back shutter, lifted my crock from the chimney niche, and backed out of the window bent double, so that the first thing he offered my bear Barnaby was the seat of his Barnstead wool trousers. Barnaby took out a piece the size of a Sunday pork chop and then spat it out on the snow, because he knew cheap stock when he tasted it. I will grant Hosea this much: he never dropped the crock. I sewed him up with eleven stitches of my dental silk and billed him a dollar and six bits, which he still owes me. The yeast never even took a chill, and it rose that Tuesday as if nothing had happened.

My guest by the stove, the Blue Ridge herbalist Clara Higgins, told me how her granny kept her crock through a winter when the snow came over the fence rails. She wrapped it in her wedding quilt and put it in the middle of the bed, on the warm side. Her granddaddy got the cold side against the log wall. When he complained, Granny answered: "the batter don't snore, and it don't kick, and it gives something back in the morning."

Mountain Ferments and a Feud

Miss Higgins brought more stories. In Botetourt County in the fall of '64 a man set a barrel of persimmon beer working in his smokehouse. The beer was made from frost-soft persimmons mashed with wheat bran, baked into cakes and crumbled into water, and he drove the head down tight to keep the coons out. A warm spell set the barrel "talking," as the mountain people say of a working beer. At midnight the head blew off with a bang like a musket. The Home Guard, all old men and boys, turned out with squirrel guns sure that Yankee cavalry had come over the ridge. What they found was one old man in his nightshirt, dripping persimmon beer and holding a ham.

There was also the Feud of the Weak Emptins. Mountain law says that a borrowed cup of mother must be given back strong, fed and lively. One borrowing came back flat, the lender said so out loud at a burying, and the two families did not speak for twenty years. The feud ended only when a grandchild from each side married, and the bride went off with a crock of the very same mother, fed until it was fit to crawl out of the jar. Her great-grandfather, for his part, would not let anyone wash his Winesaps before pressing, saying that washing them washed off the working. He was right, because that gray bloom on the apple skin is a whole crowd of Liebig's little animals. Take heed, though, that a fruit mash carries pectin and makes more wood-spirit poison in the early part of a run than corn does. The fruit man must cut his heads twice as honestly.

The Experiment at the Apparatus

Boil a double handful of hops in two quarts of water for twenty minutes or so. Strain it over four or five boiled and mashed potatoes, and stir in a cup of flour and a spoon of molasses. Do not pitch the old yeast until the mixture is down to blood heat. If you cannot hold your finger in it to a slow count of ten, it will kill your yeast, and near a hundred and forty degrees by the glass the yeast dies outright. For corn, cook cracked corn to a porridge, add malted barley or rye once it has cooled some to turn the starch to sugar, cool the tub to lukewarm and pitch. Dr. James Crow, a Scotch physician at the Oscar Pepper still-house on Glenn's Creek in Woodford County, Kentucky, measured everything and gave the trade sour mash: a quarter or so of the spent backset goes into each new mash, so the yeast is happy, the spoilers are not, and every batch comes out like the last. The working mash breathes carbonic gas, so keep the room airy. Remember too that a starved or scalded yeast gives off the rotten-egg stink that the copper must then catch, so a healthy yeast does half the copper's work before the fire is lit. Heat slowly and never leave a running still. Throw away the foreshots and heads, keep the hearts, and set the tails aside to run again.

Ash, Oak and Thunder

Rabbit Miller of Wilkesboro asked whether hickory ash or red oak shavings in the thump keg clean out bad heads. Ash is pearlash, an alkali, and it will soften the vinegary bite of a mash gone too far sour. It never touches the poison, which boils off early and light. Only a jar, a nose and a willingness to pour the front of the run on the ground will save you there. Red oak is full of open pores, so many that I once blew pipe smoke clean through a stave at a cattle show and won a goose by it. That is why coopers use white oak. Red oak shavings in a thump keg give only a little color and bitter tannin. As for thunder souring the mash, it does no such thing. The spoilers thrive in hot, wet August weather, and thunder merely arrives on the same day and takes the blame. Keep your crock cool and clean in the dog days, feed it, and keep any Barnstead man well away from it.