A Natural History of Yeast, and Why It Matters

A Natural History of Yeast, and Why It Matters

(Excepted from The Art of Baking with Natural Yeast: Breads, Pancakes, Waffles, Cinnamon Rolls and Muffins. Available here.)

Natural yeast has all but vanished from modern kitchens.

Few people realize that the yeast in grocery stores is not a naturally-occurring substance. Laboratory created in 1984, the yeast sold today is so foreign to our digestive systems that some people develop allergies to the yeast itself. This quick-rising yeast appears increasingly connected to the nutritional and digestive disorders that plague so many today, including Celiac’s disease, gluten-intolerance, acid-reflux disease, wheat allergies and even diabetes. Both modern science and traditional wisdom tell us that natural yeast has health benefits that simply cannot be matched by modern yeast.

Beyond health benefits, natural yeast is simple to use, costs nothing, tastes wonderful, completely cuts out the need to buy commercial yeast, and drastically reduces the need for baking powder and baking soda. You can easily use it not only to make bread, but also waffles, pancakes, breadsticks, pizza dough, scones, rolls, and even old-fashioned root beer.

Natural yeast breaks down harmful enzymes in grains, maximizes the nutritional availability of natural vitamins, minerals, and fiber in wheat, converts wheat into an easily digestible food which will not spike your blood sugar level. Natural yeast is both pre-biotic and pro-biotic, encouraging important good bacterias in the body. It discourages weight gain, and turns the phytic acid found naturally in wheat into a cancer-fighting antioxidant.

Through history, bread has been a staple of health and nutrition. Egyptian pharaohs were buried with model bakeries -- seen today in the British Museum. Archaeologists have uncovered huge real-life bakeries used to feed the workers who built the pyramids. Yet the Egyptians did not have yeast sealed in foil packets or jars, nor did the pilgrims or settlers. There were certainly no yeast vendors waiting at Plymouth Rock, or strung along the handcart trail leading West. So where did families through history get yeast? The answer is simple. From family and community, and originally, from the air.

Yeast is a single-celled fungus, and the first domesticated living creature in history. Modern science has identified more than 1,000 different varieties of wild yeast. These organisms are so small that hundreds of millions, if not billions, fit into a single teaspoon.

Wild yeast is everywhere -- in the air you breathe, on the bark of trees, on leaves. Ever seen the white film on backyard grapes? That’s wild yeast. The same film can be found of juniper berries. For centuries, both berries have been used as natural “start” for bread yeast.

But not all yeast varieties are the same. For example, the kind of yeast used to make beer is not the same kind of yeast used to make bread. Different natural yeasts have different flavors -- some are strongly sour, some are mildly sour, and some are not sour at all. Natural yeast is sometimes mistakenly referred to as sourdough, but with the right strain of yeast, it doesn’t have to be sour unless that is the flavor you prefer. Some natural yeasts are better are raising bread than others. This is why the best strains of natural yeast has been passed down through generations and communities.

Until the 19th century, homemade yeast was the only kind there was. In 1857 Louis Pasteur discovered that living organisms -- yeasts -- were responsible for fermentation. Yeast was already an important business, even though no one had understood how it worked. The production of commercial yeast began in France in the 1850s. In the U.S., compressed yeast cakes were introduced to the nation at Philadelphia’s Centennial Exposition in 1876 , which drew 10 million visitors. When America entered World War II, yeast companies developed dry yeast for the military which did not require refrigeration. And then in 1984, rapid-rising yeast was invented in U.S. laboratories.

Today that yeast has all but replaced natural yeast. But not everyone is convinced that the convenience of super-fast yeast outweighs the health benefits of the slow rising process of natural yeast.

“The commercial bread-making industry figured out how to isolate strains of yeast that made bread raise very quickly compared to the old-fashion bread-making method; soon sourdough starts became a thing of the past for most of us,” said James and Colleen Simmons, authors of Daniel’s Challenge and Original Fast Foods. “What we didn't know when we traded Old-World leavening techniques for quick-rise yeasts, is that not everything in wheat is good for you. In fact, there are several elements in wheat that are down-right problematic and that have led to grain intolerances in about 20 percent of today's population. When you compare what happens to the bread when it is leavened with commercial yeasts versus a good sourdough starter, another story unfolds… The sourdough starter contains several natural strains of friendly bacteria and yeasts that also cause bread to rise; however, these friendly bacteria also neutralize the harmful effects of the grain. They neutralize phytic acids that otherwise prevent minerals found in the grain from being absorbed properly; they predigest the gluten, and they also neutralize lignans and tanins found in wheat” (quoted by permission).

Here is what science can prove: The slow rising process of natural yeast has many critically important health benefits. Natural yeast slows digestion to help you feel full longer, making it a natural way to eat less. The organic acids produced during natural yeast fermentation lower the glycemic index of bread (2004, Emerging Food Research & Development Report). Best of all, natural yeast lowers the body’s glycemic response to all carbohydrates. An intriguing 2009 study showed that not only did natural yeast bread lower the glycemic response better than whole wheat bread made with commercial yeast, but the body’s glycemic response remained lower when eating a meal hours later. No other kind of bread produced the same response (2009, University of Guelph, Ontario).

Natural yeast also controls heartburn and acid-reflux disease with almost 100 percent success. A natural yeast-based product has been shown in clinical trials to reduce the incidence of cold and flu. Another natural yeast based product has been show to simultaneously boost the immune and improve bone health. A University of Michigan study showed that a once-a-day supplement of a yeast-derived compound called EpiCor significantly reduced seasonal allergy symptoms, including nasal congestion, runny nose, and watery eyes (Biotech Business Week). Natural yeast bread counteracts “the deleterious effects of whole wheat on iron absorption, whereas sourdough bread making enhanced iron absorption” and “is a better source of available minerals, especially magnesium, iron, and zinc” (Nutrition, 2003). The lactic acid and natural salts in natural yeast bread slow down digestion, which means you feel full longer.

Unlike rapidly rising commercial yeasts, natural yeast is a source of the beneficial bacteria that we all need to get the most nutrition and essential minerals from the digestion process. "In the normal scheme of things, we'd never have to think twice about replenishing the bacteria that allow us to digest food," said Sandor Ellix Katz, author of "Wild Fermentation: The Flavor, Nutrition and Craft of Live-Culture Foods,” in a newspaper interview. Katz called antibiotics, chlorinated water, and antibacterial soap “factors in our contemporary lives that I'd group together as a 'war on bacteria’... If we fail to replenish [good bacteria], we won't effectively get nutrients out of the food we're eating."

Unwanted food-borne fungi are no match for the lactic acid produced by natural yeast, which has been shown to inhibit the growth of certain bacteria and mold. And sourdough bread has long been known to have a longer shelf life (Life Science Weekly).

In July 2005, a Canadian-based company called Iogen became the first company to license genetically altered yeast for commercial use. The news was announced in an industry publication called Renewable Fuel News. The yeast was genetically altered at Purdue University to produce 40 percent more cellulosic ethanol than wild yeast. Purdue researchers, who patented the yeast, altered the genetic structure, adding three additional genes, which makes it possible to convert glucose and xylose to ethanol at the same time. The goal was to reduce the cost of producing ethanol using yeast. This has raised new fears that this genetically altered yeast could contaminate natural yeast just as pollen from genetically modified corn has now begun to contaminated the nation’s heirloom corn seed. Because yeast is found everywhere, even in the air, how can genetically modified yeast be kept from mixing with natural yeast? If indeed modern super-rising yeasts are potentially contributing to health problems, pure natural yeast must not be allowed to be contaminated by patented, genetically modified yeast.

A word of caution. If you type “sourdough starter” into Google, you will get hundreds of recipes for starting “sourdough” from commercial yeast. But very little grocery store yeast is now true natural yeast. The best way to get real natural yeast is from someone using a documented strain. The author, Caleb Warnock, mails flakes of natural “sweet” yeast to anyone who requests them at no charge, along with instructions for growing out the yeast. And once you have a start of natural yeast, you can have it for the rest of your life. You can dry it, freeze it, keep it in the fridge, or grow it on your kitchen counter. To get a start of the author’s documented 200-year-old strain of natural yeast, send an email to calebwarnock.yahoo.com.

Melissa and I never charge for natural yeast. We always give it away for free. We have spent more than two years, and many thousands of dollars ($2,000 just on photography for the book alone) creating natural yeast recipes for the modern kitchen. We will never get rich off this project. We each get paid less than 50 cents per copy of the book sold. I tell you all this because I am hoping that, if you find the information below useful, you will go to Amazon.com and pre-order The Art of Baking with Natural Yeast. I have a personal reason for asking everyone to do this. It is because all pre-orders count toward first-week sales, so if I can get enough people to pre-order the cookbook, it will debut on the bestseller’s list, which would bring some much-needed attention to the health benefits of natural yeast, to our two years of work, to the hundreds of hours of research, and to our book. So if you find the information on this blog useful, please pre-order the book on Amazon. And not to press my luck, but I have confirmed that if you buy two copies from Amazon, the shipping is FREE :)

The Art of Baking with Natural Yeast: Breads, Pancakes, Waffles, Cinnamon Rolls and Muffins is available here.

And just for fun -- and so you can see why it took us two years to create the recipes for our new book -- take a look at these historic natural yeast recipes! Just to be clear, these are VERY OLD and are NOTHING LIKE the modern recipes in our new book! :)

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HISTORIC RECIPES (spelling and grammar are as originals]

“The Accomplisht Cook,or the Art & Mystery of Cookery: Wherein the whole ART is revealed in a more easie and perfect Method, than hath been publisht in any language.” By Robert May, 1685.

To make buttered Loaves.

Season a pottle of flour with cloves, mace, and pepper, half a pound of sweet butter melted, and half a pint of ale-yeast or barm mix't with warm milk from the cow and three or four eggs to temper all together, make it as soft as manchet paste, and make it up into little manchets as big as an egg, cut and prick them, and put them on a paper, bake them like manchet, with the oven open, they will ask an hours baking; being baked melt in a great dish a pound of sweet butter, and put rose-water in it, draw your loaves, and pare away the crust then slit them in three toasts.”

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The Cook and Housekeeper’s Complete and Universal Dictionary, including a System of Modern Cookery, in all its Various Branches, Adapted to the use of Private Families. By Mrs. Mary Eaton, 1822:

YEAST.

It was usual some years ago to reduce porter yeast to dryness, and in that state it was carried to the West Indies, where it was brought by means of water to its original state, and then employed as a ferment. Another method of preserving yeast. Take a quantity of yeast, and work it well with a whisk till it becomes thin; then have a broad wooden platter, or tub, that is very clean and dry, and, with a soft brush, lay a layer of yeast all over the bottom, and turn the mouth downwards that no dust can fall in, but so that the air may come to it, to dry it. When that coat is very dry, lay on another; do so till you have as much as you intend to keep, taking care that one coat is dry before you lay on another. When you have occasion to make use of this yeast, cut a piece off, and lay it in warm water; stir it till it is dissolved, and it is fit for use. If it is for brewing, take a whisk, or a large handful of birch tied together, and dip it into the yeast, and hang it up to dry; when it is dry wrap it up in paper, and keep it in a dry place; thus you may do as many as you please. When your beer is fit to work, throw in one of your whisks, and cover it over; it will set it a working as well as fresh yeast. When you find you have a head sufficient, take out your whisk and hang it up. If the yeast is not all off, it will do for your next brewing.