Yeast Equivalencies
1 ounce fresh yeast = 0.4-0.5 ounce Active Dry yeast = 0.33 ounce Instant yeast
* A consumer packet of yeast = 0.25 ounce = 7.5 grams

 

Instant Yeast
1 teaspoon = 0.11 ounce = 3 grams
2 1/4 teaspoons = 0.25 ounce = 7.5 grams
3 tablespoons = 1.0 ounce = 28 grams

 

Active Dry Yeast
1 teaspoon = 0.10 ounce = 3 grams
2 1/2 teaspoons = 0.25 ounce = 7 grams
3 tablespoons + 1 teaspoon = 1 ounce = 28 grams

 

Yeast Substitutions
Instead of 1/4 ounce envelope active dry yeast, you can use 1 scant tablespoon active dry yeast OR 1 (0.06-ounce) cake compressed fresh yeast.

 

Water Temperatures to Activate Yeast
Yeast is activated by the addition of water, and different yeasts, bakers, and breads call for slightly different water temperatures.

 

Cool: 75°F–80°F
Tepid: 80°F–90°F
Lukewarm: 95°F–105°F
Warm: 105°F–115°F
Hot: 115°F–120°F.

 

Types of Yeast
There are many types of yeast. The most commonly available are fresh (or compressed), active dry, rapid-rise, and instant.

 

Fresh (or compressed) yeast: Fresh yeast is sold in 0.06-ounce cubes, 2-ounce cakes, and 1-pound blocks. It is soft, a little rubbery, and tan-grey colored with no discoloration and breaks with a clean edge. It is highly perishable and should be wrapped air-tight and kept in the refrigerator or frozen. It has a very short shelf life of about 2 weeks being held below 30°F and frozen for several months.
Active dry yeast: Yeast that is dormant and dried and brought to life when proofed in lukewarm and warm water (105°F-115°F). It can be stored at room temperature, but is best preserved in the refrigerator or freezer. It is sold in dated 0.25-ounce packets and 4-ounce jar in the supermarket. Do not use packages that have exceeded their expiration date.
Rapid-rise (or quick-rise) yeast: A strain of yeast that is fed with larger amounts of phosphorus and ammonia to increase the enzyme activity. It cuts the dough’s rising time in half. This yeast works best when added directly to the dry ingredients without prior rehydration, and with the liquid temperature about 120°F-125°F. There is a small loss of flavor and storage quality in the finished products because of the yeast’s fast fermentation. It is interchangeable with other dry yeasts if necessary. It is available in 0.25-ounce packets and 4-ounce jars.
Instant yeast: A European strain dried yeast that contains three times more “live” yeast cells than active dry yeast. Instant yeast doesn’t need to proof in liquid; it can be added directly to the recipe with the dry ingredients (although soaking wouldn’t hurt it). It is coated with ascorbic acid and a form of sugar that enables the yeast to activate immediately on contact with warm liquid. It also has a greater resistance to temperatures and can be activated in temperatures ranging from tepid to hot (80°F-120°F). Instant yeast enables dough to be baked without any initial rising time. Store it in an air tight container in the freezer.

Baking Soda

An alkaline, when baking soda is combined with an acidic ingredient (buttermilk, yogurt or molasses) it produces carbon dioxide gas bubbles that cause a dough or batter to rise.

Baking Powder

A leavener than contains a combination of baking soda, an acid (cream of tartar) and a moisture absorber (cornstarch). When mixed with a liquid it releases carbon dioxide gas bubbles that cause a bread or cake to rise.

 

Types of Baking Powder
Double-acting: The most common form of baking powder which releases some gas when it becomes wet and the rest when exposed to oven heat.
Single-acting: A baking soda that releases carbon dioxide gas bubbles as soon as it is moistened.

 

Baking Powder Substitution
Instead of 1 teaspoon double-acting baking powder, you can use 1/4 teaspoon baking soda plus 5/8 teaspoon cream of tartar OR 1/4 teaspoon baking soda plus 1/2 cup buttermilk or sour milk (reduce liquid in recipe by 1/2 cup) OR 1/4 teaspoon baking soda plus 3/8 cup molasses (reduce liquid in recipe by 1/4 cup, adjust sweetener) OR 1 1/2 teaspoon phosphate or tartrate baking powder