Where Does Brewer's Yeast Come From?

Brewer's yeast may be familiar to you, especially if you're a beer drinker, vegan or vegetarian. If you're health conscious, you may have heard of nutritional yeast, made from the same source as brewer's yeast but processed differently. Baker's yeast also comes from the same source but is live, used only for baking. Although brewer's yeast has been around for thousands of years, science continues to discover new ways to create and utilize brewer's yeast.

Background

Brewer's yeast itself isn't found in nature. It's made domestically from a single-celled fungus or yeast called Saccharomyces cerevisiae that is ground and dried. Saccharomyces cerevisiae naturally appears where there are a lot of carbohydrates in the form of sugar, such as on grape skin and grains. Brewer's yeast uses this sugar as a form of energy in order to reproduce, turning sugar into carbon dioxide and alcohol, otherwise known as fermentation.

History

According to Dr. Richard M Walmsley and Dr. Patrick Keenan of the Department of Biomolecular Sciences in the United Kingdom, brewer's yeast has been around since ancient times and was most likely discovered by accident. Saccharomyces cerevisiae may have caused a forgotten batch of grape juice to ferment into wine. Beer may have been made unexpectedly by gruel or porridge sitting around. During that time period, yeast made its way in bread-making also, perhaps happening after wine or beer spilled onto the dough. Details about yeast's components weren't discovered until 1630 after the invention of the microscope.

Function

Brewer's yeast is either grown for harvest on grains, hops, sugar beets or molasses, or it's what's left over after beer has been brewed and processed. If grown for harvest, brewer's yeast has a bitter taste, showing it's rich in chromium. "Debittered" brewer's yeast tastes better but isn't considered a "true" brewer's yeast since some of the nutrition is lost in the processing.

Expert Insight

According to the April 2009 Science Daily, researchers from the VTT Technical Research Center of Finland recently genetically modified lager yeast strains by using DNA from an ale strain. The result was a special strain of brewer's yeast that created a concentrated beer with a higher alcohol content. They said these new yeasts "fermented VHG [very high gravity] wort faster and more completely, producing beers containing more ethanol and less residual maltose and maltotriose [malt sugar]."

Nutrition

Brewer's yeast contains the B vitamins such as vitamin B1, B2, B3, B5, B6, B9 and biotin. Vegans and vegetarians take brewer's yeast for these B-complex vitamins as well as for its protein, which is 16 g for every 30 g of brewer's yeast. Brewer's yeast also contains many important minerals and is one of the best sources of chromium. Nutritional yeast is fortified with vitamin B-12.

Tips and Warnings

As a supplement, take 1 to 2 tbsp of brewer's yeast each day.

Avoid brewer's yeast if you have an allergy to yeast or if you're prone to yeast infections (although it's not the same vaginal yeast).

Consult with your doctor before taking brewer's yeast if you are taking antidepressants like Monoamine Oxidase Inhibitors (MAOIs) .

If you're diabetic, ask your doctor first before taking brewer's yeast since it can cause a drop in blood sugar (hypoglycemia).

You may experience bloating and gas if you're not used to taking brewer's yeast. If so, just take smaller amounts and increase over time.