Active dry yeast and instant yeast

Nearly all breads and pastries will perform equally well with any of the available yeast products (fresh, active dry, quick rise, or instant). Active dry yeast, developed about 150 years ago, is sold in sealed, foil-lined packets. But in the packaging process, about 25% of the yeast cells die off, releasing a small amount of glutathione, which causes relaxation of gluten (this makes it a good yeast for pizza dough, but it’s not ideal for all dough products).

Instant yeast, also called quick rise or rapid rise, came along about 30 years ago and has become more popular as its availability has increased. Because none of the yeast cells die during packaging, it requires 25% less instant yeast than active dry yeast to leaven a loaf. The biggest advantage of instant yeast is that it dissolves directly in dough without having to be hydrated in warm water the way active dry yeast often does. (The mini baguette recipe uses active dry yeast without first hydrating it, but it works in this case because the dough is exceptionally wet.)

Fresh yeast, also called compressed or cake yeast, is sold refrigerated in foil-wrapped blocks and cubes. It’s a moist product and has a limited shelf life of about three weeks, even if refrigerated. It is also harder to find for home baking. Professional bakers have traditionally liked this type of yeast because it’s what they learned to bake with, but many of them are now switching to instant yeast because of its extended shelf life and ease of use.

What is the difference between active dry yeast and instant yeast (also known as bread machine yeast)? Instant yeast is a little more potent than active dry yeast and can be mixed in with your dry ingredients directly. I generally find it easier to work with. Active dry yeast works just as well as instant yeast, but requires being activated in a little bit of warm water before being added to the rest of the ingredients. Failure to properly activate it will result in your loaf not rising adequately.

Can I substitute active dry yeast for instant yeast in my recipe (or vice versa)? Yes. If you are substituting active dry yeast for instant yeast in a recipe, read the instructions on the package to figure out how to activate the yeast before adding it to the recipe and reduce the amount of water you add later in the recipe by the amount of water you proof the yeast in (i.e., if you activate the yeast in a half a cup of water, add a half a cup of water or milk less later so that you end up with the same total amount of liquid in the recipe).

You may also want to add about 20 percent more yeast to the recipe than what is called for, although using less yeast and letting it rise more slowly will result in a more flavorful loaf. If you are substituting instant yeast for active dry yeast, you can reduce the amount of yeast you use in your recipe by approximately 20 percent. Be sure not to forget to increase the amount of water you add to the dry ingredients by the amount that you would proof the active dry yeast in, so that you end up with the same total amount of liquid in the recipe.

What about fresh yeast?Professional bakers often use fresh yeast. If you encounter a recipe that uses fresh yeast, divide the weight by 3 to calculate the proper amount of instant yeast to use.

Sometimes when I make bread (especially brioche) I notice a very strong, unpleasant alcohol taste in the finished loaf. What causes this and how can I avoid it?

What you are smelling is yeast fermentation—the conversion of sugars into alcohol and carbon dioxide. When dough overferments, it gives off a stale beer smell. Some of this alcohol will bake off, but some of it may remain in the finished bread. Dough made with a high percentage of yeast and sugar, such as brioche and other soft, rich bread products, are more vulnerable to overfermentation than crusty breads such as French or Italian bread, which use small percentages of yeast.

If your bread is overfermenting it may be because the dough is too warm or, if kept overnight in the refrigerator, it did not cool down quickly enough to stop the fermentation. Try making the dough with colder water or reduce the yeast by about 10%. Brioche, especially, should be chilled immediately after mixing to control the fermentation.

Quick Instant Yeast Conversion Table

• 1 g = ¼ tsp
• 2 g = ½ tsp
• 3 g = ¼ tsp＋½ tsp
• 4 g = 1 tsp
• 5 g = 1 ¼ tsp

Summary 

• Cake (moist) - the traditional live yeast; needs to be dissolved in water
• Active dry - the traditional dry yeast; needs to be dissolved usually with a bit of sugar
• Instant - contains a bit of yeast enhancer (citric acid, maybe some other stuff?) and is possibly more concentrated than active dry; does not need to be dissolved
• Bread Machine - exactly the same as instant in a different package
• Rapid Rise - larger amount of yeast enhancers and other packaging changes to the granules. Does not have to be dissolved. Works very fast and is intended for straight doughs that you want to complete within an hour or so. Generally not used by artisan bakers who seek slower, not faster, rise.