Know Your Yeast

know your yeast different types of yeast in separate bowls on white background

Yeast. It’s the seemingly magical ingredient that takes a bowl of water, flour, and salt from simple ingredients to a fluffy ball of beautiful dough ready to be kneaded, shaped, and baked into mouthwatering bread. It gives dough the lift, flavor, and airiness that make fresh baked bread so irresistible. The tricky part? Yeast is a living organism, a fungus, that comes in multiple forms and needs proper care to produce the carbon dioxide needed to make bread rise. Don’t fear yeast. Know your yeast!

Types of Yeast

Fresh Compressed—Also known as cake yeast, this form is live, moist yeast pressed into squares and sold in select stores, often seasonally. It has a very short shelf life, so check expiration dates meticulously.

Active Dry—Our test kitchen’s most commonly used variety, this form of yeast comes in pellets made up of live yeast cells surrounded by dehydrated cells and a growth medium. Typically, recipes call for rehydrating, or proofing, the pellets in lukewarm water to activate the dormant yeast.

Instant—This form comes in smaller pellets that contain more live cells than active dry yeast pellets. It can be added directly to dough or proofed in lukewarm water. Its smaller shape and composition mean these pellets activate quicker than those of active dry yeast.

Rapid-Rise—A type of instant yeast also known as Bread Machine Yeast, this form can be mixed straight into dry ingredients. These smallest pellets are a form of instant yeast that dissolves and produces carbon dioxide faster, making your dough rise, well, rapidly. The downside to this quick rise is that the yeast doesn’t have time to develop its own flavor, and many find that bread made with it just doesn’t taste as good.

Sourdough Starter—Many people overlook the sourdough starter as a form of yeast. In reality, this mixture of flour and water that is allowed to ferment naturally is the oldest form of passing the tiny microscopic organism from one batch of dough to the next—used well before science allowed us to see yeast by putting it in pellet form. A live culture of yeast lives in the flour and water mixture you create, feed, and use. People have been known to keep starters alive for decades.


What type should you use?

All yeasts are not created—or used—equally. We recommend using the type and amount of yeast called for in the recipe you are following. However, there is a fairly simple conversion that works if you need to substitute yeasts in a pinch. If a recipe calls for 1 ounce of fresh yeast, you only need .5 ounces of active dry or .4 ounces of instant. A sourdough starter should only be used in recipes that call for it, as it adds a very notable flavor difference.

Yeast Do’s and Don’ts:

  • Do use yeast! Don’t be intimidated by bread recipes. There’s nothing more satisfying than pulling a home-baked loaf of bread from the oven.
  • Do make sure to use the form of yeast called for in the recipe, or make the correct conversions
  • Don’t use hot water. Make sure your water is lukewarm (between 80-100°). Hot water will kill the yeast.
  • Don’t add salt before the first proofing. Salt can slow or kill yeast growth, depending on the amount. Wait until after you have bloomed your yeast to add the salt.
  • Don’t use out-of-date yeast. Expired yeast yields a poor rise. Always check the date on your yeast before baking.
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  1. I have tried to make yeast rolls and they do not rise. i used flehmann yeast, I have repeatledly failed. what tpye of yeast do you use and flour. do you have a good failproof recipe for yeast rolls/HELP.

    • Hi Evelyn, we do have a number of reliable rolls recipes. You may want to start with our Parker House Round Rolls: (the dough recipe is at the link in the bottom of the post). They are buttery and perfect for any occasion! As for yeast, we often use active dry yeast. We have had success using Fleischmann’s, but no matter what brand you use, be sure that it is not expired. Expired yeast will not perform as well. Also, be sure that your kitchen is warm (cold air will slow the rising process), your water or milk is warm and not hot (hot liquid can kill yeast), and that your salt does not touch your yeast before it is activated (salt can also kill yeast). For this recipe, we used King Arthur Flour’s Unbleached All-Purpose Flour. I hope this helps!


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