Click here to see how to proof your yeast (Video courtesy of Cook'n with Pillsbury).
It's amazing to me that such tiny 'critters' as yeast can raise so much dough. By simply providing moisture, warmth, and food (flour, sugar), those few teaspoons of yeast multiply and go to work. A living organism, yeast converts the starch in flour into sugar. It then ferments these sugars and additional added sweeteners into carbon dioxide and alcohol. The gluten strand framework traps the carbon dioxide, causing the dough to rise, while the alcohol (which bakes out) provides that homey, delicious flavor of which we're so fond.
The dough continues to rise until all the oxygen is utilized. If dough is left unattended, the alcohol levels increase, kill the yeast completely, damage the gluten framework, and result in a dense brick of bread with an alcoholic odor. Recipes often state to let dough rise until "double in size." Once it hits that 'double' mark, punch it down. If you're worried about not knowing when to punch it down, use a ruler. Or, you can relive my experience of walking into the kitchen to find collapsed dough running over the sides of the bowl and plopping onto the floor.
In order of potency, the following types of yeast available for baking and how to interchange them in recipes follows.
Compressed Yeast. Also known as fresh, cake, or moist, this yeast is very perishable and loses its potency a few weeks after it's packed. However, this potency is why many professional bakers prefer it to other types of yeast. Less temperamental, it is activated in a wide range of temperatures and has high gassing power. Some believe it adds a deeper flavor to bread than dried yeast. Before you buy, check the expiration date. You can store it, well wrapped, in the refrigerator, or store it in the freezer for up to 4 months. Defrost it the day before baking by placing it in the refrigerator.
To use, crumble the cake with your fingers into a small bowl. Add 1/4 cup of the liquid from your recipe; stir until smooth. Continue as directed in the recipe. Alternatively, Fleischmanns (yeast producers) says you can crumble the dry yeast right into your dry ingredients.
Instant Yeast. (Also known as rapid-rise, fast-rising, European yeast, or "bread-machine yeast.) A soft outer shell that does not require pre-softening in warm water coats instant yeast cells. The shell absorbs moisture to activate the yeast as it is mixed in the dough. For this reason, instant yeast can be added directly to the dry ingredients for added convenience. It also encourages fast rising. While some feel this is an advantage in our time-pressed age, others enjoy the flavor incorporated in bread through the slow fermentation (slow rising) of regular yeast. Store in an airtight container in the refrigerator or freezer. (4)
Active Dry Yeast. These yeast cells are alive but not activated until the hard outer shell is softened by water. This generally takes five to ten minutes. Adding a 1/2 teaspoon of sugar aids the activating process. Put some of the liquid from your recipe (1/4 cup or as specified) in a small cup or bowl and stir in the yeast and sugar until dissolved and no longer lumpy. Set the timer and work on compiling the remaining ingredients needed for your bread. When the time is up, the yeast should look foamy and larger in size. If after 15 minutes, the yeast has not grown or become foamy, it is inactive. The yeast was either killed by water that was too hot or it is too old.
My personal favorite, active dry yeast is economical, keeps well, is readily available in bulk packages, and is quite dependable. Store in an airtight container in the refrigerator. Limit the yeast's exposure to oxygen and moisture by recapping the container as soon as possible after measuring yeast for baking. While bulk packages state that the yeast must be used within 2 weeks after opening, I've used active-dry yeast for up to 5 months after opening the vacuum packed bag with good results.
Yeast Conversions. When recipes call for a specific type of yeast, you can substitute the type you prefer easily. If you wish to use active-dry yeast in recipes calling for instant yeast, increase the amount of yeast called for by 25 percent. Vice versa, if you wish to use instant yeast in recipes calling for active-dry, decrease the amount of yeast called for by 25 percent. Instant yeast is much more potent than active-dry. Increasing or reducing the yeast types will encourage a better-flavored product than if you just used the yeast types interchangeably.** (4)
1 packet (2-1/4 teaspoons) active dry yeast* = .6-ounce cake of compressed yeast = 1 packet (2-1/4 teaspoons) or scant 1-3/4 teaspoons instant yeast**
* Because of improvements in yeast properties and potency by manufacturers, the amount of yeast in packets has decreased. While older recipes call for 1 tablespoon or 1 packet of active dry yeast, the new yeast packets contain 2-1/4 teaspoons yeast. You can reduce the amount of yeast used in any of these older recipes by substituting 2-1/4 teaspoons per tablespoon of yeast.
**Packets of instant yeast contain 2-1/4 teaspoons of yeast, but using only 1-3/4 teaspoons when substituting for active dry yeast will give better results in your bread; although you may use the entire packet if you wish. Alternatively, add 2-3/4 teaspoons of active dry yeast in recipes calling for 1 packet instant yeast.
* DVO welcomes your kitchen hints and cooking or nutrition questions! Email us and we'll post your hints and Q/A's in upcoming newsletters! *