Thursday, July 27, 2006
@12:54 AM
Yeast is a tiny plant-like microorganism that exists all around us - in soil, on plants and even in the air. It has existed for so long, it is referred to as ‘the oldest plant cultivated by man. The main purpose of yeast is to serve as a catalyst in the process of fermentation, which is essential in the making of bread. The purpose of any leavener is to produce the gas that makes bread rise. Yeast does this by feeding on the sugars in flour, and expelling carbon dioxide in the process. As the yeast feeds on the sugar, it produces carbon dioxide. With no place to go but up, this gas slowly fills the balloon. A very similar process happens as bread rises. Carbon dioxide from yeast fills thousands of balloon-like bubbles in the dough. Once the bread has baked, this is what gives the loaf its airy texture.
Types of Yeast Used In Bread Making:
There are two types of dry yeast: Regular Active Dry and Rapid-Rise. The two types of dry yeast can be used interchangeably. The advantage of the rapid-rise is the rising time is half that of the active dry and it only needs one rising.
You can speed up standard yeast bread recipes by changing the yeast in the recipe. Substitute one package fast-acting yeast for one package regular active dry yeast. Quick yeast is more finely ground and thus absorbs moisture faster, rapidly converting starch and sugars to carbon dioxide, the tiny bubbles that make the dough expand and stretch.
Active Dry Yeast:
1 cake of compressed yeast equals 1 package of active dry yeast. 1 package active dry yeast equals about 2 1/4 teaspoons.
Active dry yeast has a larger particle size than Instant Active Dry Yeast, making it necessary to proof, usually water, before using. Recommended water temperatures will vary by manufacturer between 100 - 115 degrees F as measured with an Instant Read Thermometer.
Active dry yeast will keep well beyond its expiration date printed on the package for 1 year if unopened at room temperature. It will keep longer if frozen. Place directly in the freezer in its vacuum sealed container. If frozen, you can use it directly without thawing.
If opened, active dry yeast will keep 3 months in the refrigerator and 6 months in the freezer. Keep yeast in its original container with the opened flap folded closed in a resealable plastic bag. Stored at room temperature and opened without a protective outer container it loses its power at about 10% per month.
Instant Yeast - Also known as: Fast Rising, Rapid Rise, or Bread Machine Yeast
1 envelope or packet of Active Dry Yeast, Instant Yeast, Rapid Rise Yeast, Fast Rising Yeast or Bread Machine Yeast weighs 1/4 ounce or 7 grams which equals 2 1/4 teaspoons (11 mL).
Rapid rise yeast, also known as instant yeast or quick yeast, has been genetically engineered from different strains of yeast to produce breads that can be made with only one rising. Rapid rise yeast is also more finely granulated than active dry yeast, so it does not need to be dissolved in water first. It can be added directly to the dry ingredients, making it a popular choice for use with bread machines.
Instant active or RapidRise yeast is added to the dry ingredients. Then, the liquid portion of the recipe's ingredients, warmed to 120 – 130 degrees F, as measured with an Instant Read Thermometer, are added to make a dough.
Instant yeast will keep a year at room temperature if unopened. If opened, it will keep 3 months in the refrigerator and 6 months in the freezer. Keep yeast in its original container with the opened flap folded closed in a resealable plastic bag.
Testing Yeast:
Sugar is used in testing yeast. To test yeast: Add 1/2 teaspoon of sugar to the yeast when stirring it into the water to dissolve. If it foams and bubbles within 10 minutes, you know the yeast is alive and active.
Measuring Yeast:You do not need to be exact in measuring yeast. Remember it's going to multiply like crazy anyway. A little less is fine; the dough will rise more slowly and may taste better. I wouldn't increase the yeast measurements in the recipes on these pages; they are already at the high end. Way too much yeast will give an unpleasantly yeasty flavor and aroma.
