Some Simple Facts About Baking Yeast
Baking yeast is the most common name for the types of yeast you would generally use to help leaven bread and bread products. It converts the sugars in the dough into ethanol and carbon dioxide. Most of the baking yeast you use in the kitchen is the same type that is used to ferment alcohol. There are also wild yeasts sometimes found in fruits and plants, but that generally can't be used as-is for baking. It has to go through another chemical stage before you can use it in the kitchen.
Baking yeast can be purchased in several different forms. Each variety has its own advantages, so the type you choose will largely depend on what your recipe asks for, and how well-trained you are in using different yeasts to bake with.
Cream type yeast is basically a group of live cells suspended in liquid. It is siphoned off of whatever was used to grow it. The main use of cream yeast is in large bakeries where they have special heavy-duty equipment to mix and dispense their products.
Compressed yeast is baking yeast which is very similar to cream yeast, except that a lot of its liquid has been removed from it. The most well-known compressed yeast is known as cake yeast, and that is a very soft but solid form, usually light beige. It is also available as a crumbled yeast so that it can be used in bulk baking. This type of yeast is very perishable, and while it used to be more available in supermarkets, it is less widely seen now because it is so hard to keep fresh.
Active dry type yeast is one form of baking yeast that you might normally pick up at your supermarket. This type is the best and most available to everyday bakers. It also stays fresh even when it is shipped a long distance, or in very hot or very cold temperatures. This type usually contains oblong coarse yeast particles, and it has live yeast cells that are encapsulated within a coat of dead dry cells. Generally, you need to proof or rehydrate active dry yeast to use it.
Instant yeast at first glance looks a lot like dry yeast. But the granules are smaller and there are more live cells in the packaging. It is harder to keep fresh than active dry, but you don't have to rehydrate it, and you can generally add this type to any but very dry doughs. Instant yeast contains ascorbic acids in small amounts as a preservative.
Rapid-rise yeast is a type of baking yeast that was designed to give off more carbon dioxide, so that the dough product will rise faster. Bakers debate on whether this type of yeast is actually needed, because some baking experts feel that it lessens the overall flavor of the dough it is used in. The rapid rise type of yeast is commonly used in home bread making machines.
Whatever type of baking yeast you choose, you will come to value the product a great deal if you fancy yourself a baker of dough.