Types of Yeast Used in Baking
“Baker’s yeast” is the general term given to all forms of Saccharomyces cerevisiae used to make bread products. Baker’s yeast is available in several forms such as active dry, fresh (or cake), liquid, and instant.
- Active Dry: This yeast requires dissolving it in warm liquid prior to adding to a recipe and should not be substituted with or for instant yeast. Active Dry yeast should not be exposed to liquids hotter than 110 degrees Fahrenheit, or else it will kill off the yeast, a live culture. This yeast is usually sold in 1/4-ounce envelopes or 4-ounce jars.
- Fresh: Fresh yeast is sold in compressed or cake form. This type of yeast is extremely perishable, so it must be kept refrigerated and used within a couple of weeks of purchase. To use fresh yeast, it must be dissolved into a liquid prior to adding to a recipe. Fresh yeast should be proofed, or tested for potency, before each use. To proof yeast, dissolve in warm water and add a pinch of sugar. If the yeast does not begin to foam within 5-10 minutes, it is no longer active.
- Liquid: This was the most popular form used prior to the invention of compressed or cake yeast in the early 19th century. Liquid yeast is basically a slurry of live yeast organisms, flour (or other carbohydrates), and water, similar to a sourdough or bread starter. As long as fresh carbohydrate is added on a regular basis, the organisms will continue to live and replicate.
- Instant: Instant yeast is the most active form that’s commercially available. This yeast does not require dissolving into a liquid before adding to a recipe and often only requires one rise. This form of yeast is very shelf-stable and can be stored in a dry, airtight container at room temperature until the expiration date. Instant yeast can be referred to also as rapid rise or bread machine yeast. Labeling instant yeast as “bread machine yeast” makes it easier for consumers to choose the correct yeast to use in their bread machines.