Foraging for Wild Yeast

Wild yeast growing on certain types of berries—or even Aspen tree bark—will create tasty sourdough bread and sourdough starter as readily as store-bought yeast.

  • 065 wild yeast - sourdough starter
    The fixin's for our sourdough starter include flour, water, a handful of berries covered with wild yeast, and a glass container...
  • 065 wild yeast - powdery white coating3
    The powdery-white leavening coats the fruit of the juniper shrub [LEFT] and the Oregon grape [RIGHT].
  • 065 wild yeast - bulging jar2
    Gases from the fermenting "sponge" expand in the jar's plastic cover.

  • 065 wild yeast - sourdough starter
  • 065 wild yeast - powdery white coating3
  • 065 wild yeast - bulging jar2

My first experience with wild yeast took place a few years back, while I was conducting a primitive living expedition in the rugged terrain of the Pacific Northwest. At the start of the trip—as is the usual procedure on such survival adventures—each member was given a ration of whole wheat flour sweetened with a lump or two of raw sugar ... as "basic food" to supplement our gathered wild fare. Every evening we'd mix the flour with water, form the paste into a kind of tortilla, and then cook the dough in the hot coals of the fire.

The resulting "ash cakes" actually tasted good on the first day, and were even edible when the third evening came around. But by our eighth day in the woods, we all hungered for a taste of fresh-from-the-oven risen bread!

Little did we guess that the means of satisfying our craving was growing all around us! On one of the daily foraging hikes, a member of the group (who was a biochemist, budding botanist, and well-versed historian, to boot) picked a handful of autumn-ripe Oregon grape berries and explained that the white powder covering the fruit was actually an atmospheric fungus ... more commonly known as yeast!

Wild yeast spores are, he went on to tell us, practically everywhere, and—if they happen to land where there's moisture, sugar, and warm temperatures—the delicate plants will begin to grow and multiply. (Given ideal conditions, yeast can increase its own volume by more than ten times, overnight!)  

The airborne microflora are especially attracted to the sweet skin of berries and grapes. They first appear as a whitish powder, but when the membrane of the ripened fruit becomes injured (by pecking birds, perhaps), the yeasty critters slip in and begin to ferment the juice's sugars. (That's why a bowl of overripe fruit—when left in a warm room—will begin to give off a vinous odor.)

Obviously, the fermentation process is no secret ... it was long ago perfected by our ancestors, and produces a number of sought-after beverages today! But—somewhere along the line—an enterprising soul (or perhaps a tipsy Egyptian baker) realized that the same yeast that ferments drinks could, when mixed with dough, be used as a leavening agent.

10/27/2019 2:40:07 PM

Louise- You can buy organic fruit at a market and use that. I've used organic apple peels, dried fruit, including raisins and grapes- all successful. There's plenty of yeast to go around.

3/28/2018 12:00:58 PM

You refer to yeast as "delicate plants" but they're not plants at all. They're not even related to plants - they're fungi, which are more closely related to animals. Wild yeasts can also be obtained from flowers like roses and azaleas, which might be a good place to search if you don't have wild berries nearby.

8/19/2017 6:40:01 PM

I'd love to get some berries or grapes with yeast spores on them but, living in a city, they're a liitle hard to obtain. Grapes or berries at the supermarket are all washed until their spores are gone. Where can I get fruit with spores? Louise



Feb 19-20, 2022
Belton, Texas

Join us for a much anticipated return to the Lone Star State! Earlybird ticket discounts are now available online.


Subscribe Today - Pay Now & Save 64% Off the Cover Price

50 Years of Money-Saving Tips!

Mother Earth NewsAt MOTHER EARTH NEWS for 50 years and counting, we are dedicated to conserving our planet's natural resources while helping you conserve your financial resources. You'll find tips for slashing heating bills, growing fresh, natural produce at home, and more. That's why we want you to save money and trees by subscribing through our earth-friendly automatic renewal savings plan. By paying with a credit card, you save an additional $5 and get 6 issues of MOTHER EARTH NEWS for only $12.95 (USA only).

You may also use the Bill Me option and pay $17.95 for 6 issues.

Canadian Subscribers - Click Here
International Subscribers - Click Here
Canadian subscriptions: 1 year (includes postage & GST).

Facebook Pinterest Instagram YouTube Twitter flipboard

Free Product Information Classifieds Newsletters