Have you ever stopped to think what makes bread so delicious, airy and light? Yeast -- it's the little guys that help breads rise and give flavor. Unlike chemical leaveners like baking soda or baking powder, yeast is a living organism in the same family as mushrooms. When provided with water, food (in the form of sugar), warmth and some time, yeast makes our bread doughs rise by releasing carbon dioxide gas, which creates those tiny holes that make bread so light and airy.
But if you've ever wanted to try your hand at baking bread at home, you've probably been confronted in the supermarket by the many different yeasts you could choose -- active dry, instant or fresh. For the first-time baker it can be pretty confusing trying to figure out the difference. Read our guide below to learn about the main types of baking yeasts and find the one that works best for your baking needs.
Active dry yeast is probably the most widely used yeast by home bread bakers. It typically comes in single-use packets, little jars or packages. This type of yeast is basically fresh yeast that has been dehydrated into tiny granules. The yeast is dormant so it requires proofing (a.k.a. blooming), which means you should dissolve the yeast in warm water (100 - 115 degrees F) with a bit of sugar and wait for it to foam before mixing into your dry ingredients. Find active dry yeast in your supermarket's baking aisle. Store in a cool, dry place. Do not use after the expiration date.
Instant yeast has many different names depending on the brand -- it can be called "rapid rise," "quick rise" or "fast rise." Instant yeast is made in a similar manner as active dry but the tiny granules formed are more porous and don't require proofing to activate, which means you can just add them to your ingredients straight away (the moisture in the dough is enough to activate the dormant yeast). Most manufacturers claim instant yeast works 50% faster than active dry yeast. Find instant yeast in your supermarket's baking aisle. Store in a cool, dry place. Do not use after the expiration date. Photo from Butter + Cream.
As the name implies, fresh yeast is fresh. It comes in little squares that are found in the refrigerator section of your grocery store. Fresh yeast can be crumbled right into your baking ingredients or mixed with lukewarm water. A 0.6-ounce square is equivalent to one packet (1/4 ounce) of active dry or instant yeast. Store fresh yeast in your refrigerator for no more than two weeks. Discard if the yeast has hardened, turned brown or is moldy. Photo from Cooking for Engineers.
Curtis Stone shows you how to bloom yeast and activate it properly.
Source: Cooking for Engineers.
Main photo from quinn.anya, Flickr.