Is Yeast Vegan? The Vegan’s Guide to Yeast

Yeast is a vegan-friendly food. Neither animal nor plant, yeast is a microscopic member of the fungus family, and its most common culinary strain is Saccharomyces cerevisiae.

Although yeast is technically alive—it's a single-celled organism that metabolizes food into energy—it's no more an animal than other fungi such as mushrooms. Therefore, yeast is generally accepted as part of a vegan diet.

Here, we break down the many different types of yeast and explain their roles in veganism.

Why Most Agree Yeast Is Vegan

Yeast hails from the fungi kingdom. This single-celled, microscopic relative of mushrooms grows naturally on plants and in soil. Since food from the fungus family is permissible in a vegan diet, yeast is generally considered vegan. 

For more than 5,000 years, humans have enjoyed Saccharomyces cerevisiae, a strain of yeast responsible for the leavening process in bread and the fermentation in beer and wine. In its active form, S. cerevisiae converts carbohydrates to carbon dioxide, pumping the air into baked goods and providing flavor in alcohol fermentation. If heated, S. cerevisiae is inactivated or “killed” and loses its powers of fermentation. What remains is its savory taste.

In addition to its deep umami flavor, yeast provides a vegan-friendly source of amino acids, proteins, bioavailable minerals, as well as B12 and folic acid (B9). These essential nutrients can be challenging to obtain through an entirely plant-based diet.

Is Yeast Alive?

Technically speaking, yes—yeast is a living unicellular organism. In the same way that humans eat carbs and exhale CO₂, yeast “eats” sugar and produces gas. Humans harness the power of yeast’s metabolism to rise bread and ferment alcohol.  Yeast’s ability to metabolize in this way confirms its status as a “living” organism. 

Unlike members of the animal kingdom, though, yeast has just one cell and contains no nervous system. Yeast does not feel pain in the way multi-cellular animals with nervous systems can. Consequently, mainstream vegans do not see the harvesting or consuming of yeast as animal slavery, exploitation, or cruelty. However, some very strict vegans may avoid yeast because it is alive in a fundamental biological sense.

Types of Baker’s Yeast

Generally speaking, baker’s yeast is any yeast used as one of the leavening agents in bread products. These live, active forms of S. cerevisiae also give bread its distinct flavor profile. When baked, the heat kills the yeast, ending the fermentation process and making it safe for consumption in more significant quantities.

Active Dry Yeast

If you’ve ever made bread at home, you’ve likely encountered active dry yeast. This granulated, dehydrated form of baker’s yeast comes in individual packets or glass jars in the baking aisle at grocery stores. If kept at room temperature, active dry yeast has a long shelf life and remains inactive until introduced to warm water.

Fresh Yeast

Also called cake yeast or compressed yeast, fresh yeast comes in highly perishable blocks of moist, living yeast. When stored in an airtight container, fresh yeast can last a few weeks in the refrigerator. Find fresh yeast in the refrigerated section of grocery stores.

Instant Yeast

This fast-acting form of dry yeast has a smaller grain size than active dry yeast. The smaller granules make instant or "rapid-rise" yeast dissolve more quickly, hence why it can be added straight to dry ingredients therefore helping bypass the first rise of the bread. Grocery stores carry instant yeast in the baking aisle.

Wild Yeast

A catch-all term for several strains, including Saccharomyces exiguus, wild yeast can be cultivated with as little as flour and water. Alive and active, wild yeast will continue to metabolize if properly refrigerated and fed. Although sourdough starter is technically the same as wild yeast, the two differ in how they are maintained and their taste; wild yeast has a much milder flavor. Many wines also rely on wild yeast from the grapes as part of the fermentation process.

Types of Brewer’s Yeast

Like baker’s yeast, brewer’s yeast is a live culture of S. cerevisiae available in both powder and liquid form. The yeast is deactivated during the beer brewing process and is therefore rendered safe to consume in larger quantities. Cheers to that!

Lager Yeast (Bottom-Fermenting) 

Slower fermentation defines this cooler-temperature yeast. It can take weeks for bottom-fermenting yeast to bloom, elongating the brewing time but providing the distinct “clean” flavor of lagers and pilsners. 

Ale Yeast (Top-Fermenting)

It’s easy to identify top-fermenting yeast—early in the fermentation process, this fast-acting yeast creates a thick head (i.e., foam) on top of the liquid. Warm temperatures ferment ales, porters, stouts, and wheat beers in just a few days.  

Types of Cooking Yeast

Unlike baking yeasts that provide leavening power, cooking yeasts offer flavor. Granular nutritional yeast and yeast extract both come from S. cerevisiae, which is generally grown on molasses. Once harvested, the yeast is washed and dried, killing (inactivating) the yeast and making it safe for consumption in large amounts. Bring on the vegan nachos!

Yeast Extract

Best known in its brown paste form, yeast extract is the main ingredient in Vegemite and Marmite, popular brands of savory food spread in Australia, New Zealand, and the U.K. Yeast extract comes from the contents of the yeast cell without the cell wall. As a food additive, yeast extract provides umami, one of the five basic tastes. Many processed foods, including vegan products intended to have a “meaty” flavor, include yeast extract to provide this savoriness.

Nutritional Yeast

Lovingly and derisively known as "nooch" in health food circles, nutritional yeast is an inactive form of S. cerevisiae and a popular cheese substitute in many vegan recipes. You can find these yellow, granular flakes in bulk at health food stores. As veganism continues to rise in popularity, more and more mainstream grocery stores, too, carry nutritional yeast. 

Torula Yeast

Torula yeast comes from a different strain entirely—Candida utilis. A byproduct of the paper processing industry, torula yeast naturally grows on liquidized wood pulp. The yeast is collected, dried (inactivating it), and ground into a powder. Because of its smoky, rich flavor, torula yeast often appears in vegan meat and cheese substitutes.