In baking, it is important to measure yeast accurately as too much yeast can actually ruin bread. Using the proper amount of yeast and letting the dough slowly ferment, will result in a loaf of bread with more flavor.

When substituting one type of yeast for the other, remember that active-dry and instant yeast are at least twice as potent as fresh yeast.

For the beginner baker, when measuring by volume:

1 teaspoon of active dry or instant yeast = 2 teaspoons fresh yeast will suffice

For the advanced baker, especially when scaling large recipes, it is best to make yeast substitutions by weight, not volume.

Multiply the Amount of Fresh Yeast by 0.5 = Amount of Active Dry Yeast Required
Multiply the Amount of Fresh Yeast by 0.33 = Amount of Instant Yeast Required
Multiply the Amount of Active Dry Yeast by 2 = Amount of Fresh Yeast Required
Multiply the Amount of Active Dry Yeast by 0.75 = Amount of Instant Yeast Required
Multiply the Amount of Instant Yeast by 3 = Amount of Fresh Yeast Required
Multiply the Amount of Instant Yeast by 1.33 = Amount of Active Dry Yeast Required