Yeast isn’t limited to bread, beer and the grocery store shelf. It’s floating around in the air — in fact, you may have just inhaled some.This yeast, known as wild yeast, can be collected for use in a process that will be demonstrated Saturday at the fourth annual Outdoor Fun Day at Virgil Phillips Farm north of Moscow.
Yeast is a single-celled organism with strains that vary from region to region, explained Sarah Wanamaker, a Washington State University biology graduate student involved with the event. When collected and used for making bread or fermenting alcohol, these regional variances in the yeast contribute to subtle flavor differences. Even the wild yeast itself has a unique flavor.
“There’s definitely a difference from store-bought yeast,” said Wade Roberts, another WSU biology graduate student. And he should know: He’s been making his own bread for the past four years with a wild yeast starter he collected from the countertop in his kitchen. The flavor is much better, he said.
Collecting yeast can be done inside or out by setting out a mix of equal parts flour and water.
“Wild yeast will become attracted to this,” Wanamaker explained. “It’s essentially food for the yeast.”
The yeast will need to be fed daily with additional one-to-one flour-water mixture, Wanamaker said, and if a skin forms on the top, you’ll need to remove it and stir up the mixture before adding more water and flour. After about a week, froth or bubbles will appear, which is evidence that the yeast has fully colonized the mixture, which can then be used.
Besides being free, Wanamaker said that wild yeast is completely viable, unlike store-bought yeast that is damaged by processing. Using wild yeast also has the advantage of being something our bodies are already used to.
The limitations of a student budget was the primary reason Roberts started making his own bread using wild yeast — the higher-quality breads he preferred were too expensive. He now makes a loaf every week using yeast starter the consistency of pancake batter that he stores in his fridge. He’s had to play a bit with recipe ratios. Because wild yeast is viable, you get more rise from it, he said, but uses about a half to one cup of starter mix for each batch. He’ll then replace whatever he used with the same amount of flour-water mixture.
In order to get a sourdough flavor dimension to the bread, Roberts adds an acidic juice to the mix — pineapple or lemon juice, for example. That alters the environment to where certain bacteria can thrive; it’s the bacteria that creates the sourdough flavor.
Wild yeast can be used to ferment alcohol, Roberts said, though he has no experience with it personally. But he expressed the need for caution: Any type of contamination in the yeast mixture would ruin a whole batch, an issue that is less present with bread making.
Besides offering the opportunity to learn more about catching these single-celled organisms, the Outdoor Fun Day will offer a demonstration on how birds are caught for banding and an amphibian catch-and-release. A high-powered, easy-to-use microscope will be on site for examining everything from sticks to pond water.
Native plant walks will not only help attendees identify local species, but also give tips on how to use a field guide to key out plants for identification. Both a longer route and shorter, less demanding one will be available. Nature-themed face painting and crafts will also be available.
If you go:
WHAT: Fourth annual Outdoor Fun Day presented by the WSU Biology Graduate Student Association
WHEN: 10 a.m. to 2 p.m. Saturday
WHERE: Virgil Phillips Farm, five miles north of Moscow off of U.S. Highway 95