Yeast converts sugar into starch and carbon dioxide, that acts as a rising agent in breads. There are several types of yeasts available in the market, used for different purposes, depending on their properties. The classification of the different forms of yeast is largely based on their moisture content. Each form has its own pros and cons and the choice of yeast mainly depends on the requirement of the particular recipe.
Active yeast is a type of bakers yeast that is often used by home bakers, to rise dough for baking breads, cakes, and rolls. The specific strain used is Saccharomyces cerevisiae. Active dry yeast consists of coarse, oblong granules of yeast, which are live but inactive due to lack of moisture. The granules contain live yeast cells, that are encapsulated in a thin jacket of dry, dead cells, with some growth medium. These tiny yeast particles are dried and vacuum sealed. This is available in packets of different sizes and has a good increased shelf life.
It can be stored at room temperature for about a year and if frozen, it can last for more than a decade. Although dry yeast has better keeping qualities and shelf life than the other forms of yeast, it is quite sensitive to thermal shock, when actually used in recipes.
How to Use It?
Unlike most forms, dry yeast cannot be used directly. It has to be 'proofed' or activated, before use. Activating dry yeast is a very simple process and takes just a few minutes.
- In a small bowl, pour some lukewarm water. Dry yeast activates best in water that is between 110 and 115°F. Any temperature higher than that will kill the yeast and the dough will not rise.
- Stir in 2 tablespoons of granulated sugar into water until it dissolves completely.
- Now, add the dry yeast to this warm sugar solution and stir vigorously. The sugar acts as food for the dormant yeast.
- Cover the bowl with a plastic wrap or a dish towel and set it aside for about 10 minutes.
- Remove the plastic wrap and check the mixture for bubbles. If the yeast has become foamy or bubbly, it means that is activated and is ready for use in your yeast bread recipe.
Once it is activated, it can be used directly, as per the demand of the recipe. Mix it with the other ingredients and it is all set to rise the dough. This variety is readily available in the market in individual packages, most containing 2.5 teaspoons of yeast. It is very important to follow the instructions given in your cook book for raising the dough, as excess yeast may cause your bread to become sour.
Active dry yeast is preferred over the instant variety for handmade recipes due to its delicate nature. When using the dry variant, always remember to check the package, for the expiry date. If you intend to buy packages in bulk, store carefully in airtight containers.