Working with Yeast
Yeast is a crucial ingredient in breads like baguette and brioche, but it can seem a bit mysterious. Read on to learn about the science of yeast, the different kinds of yeast out there, which we like to use in the test kitchen, and our favorite tips for success.
Tips for Working with Yeast:
Salt kills yeast, so when you're adding bread ingredients to a bowl, it's always best not to pour the salt directly on top of the yeast, or vice versa.
Yeast begins to die at about 130 degrees, so make sure that the water used to make bread dough is not too hot. We find that 100 to 110 degrees works best—it's warm enough to give the yeast a jumpstart, but not so hot that it damages the cells.
Most types of yeasted dough rise best at room temperature (about 70 degrees). While it's possible to hasten rising times by setting the dough in a very warm spot like a gas oven heated by the pilot light, the flavors generated by an expedited fermentation are not fully developed. But in the winter, this may be a more attractive option than a cold, drafty kitchen countertop.
Cake Yeast
Cake yeast, aka fresh yeast or compressed yeast, is stocked in the refrigerator section of the store. This type of yeast, sold as little cubes, is reliably active, but very perishable, which is why cake yeast is used more often in commercial bakeries than in recipes for the home kitchen.
Active Dry Yeast
Active dry yeast sold in packets or jars is probably the most commonly called-for type of yeast in bread recipes. To produce active dry yeast, yeast is given heat treatment that kills the outermost cells. Therefore, in order to use active dry yeast, the granules must first be proofed, or dissolved in liquid, with some sugar to speed up the process. Proofing sloughs off the dead cells and renders the yeast active.
Instant or Rapid-Rise Yeast
Instant or rapid-rise yeast is much like active dry yeast, but has undergone a gentler drying process that has not destroyed the outer cells. Instant yeast does not require proofing and can be added directly to the dry ingredients when making bread—hence the name "instant."
In the test kitchen, we prefer instant yeast for its convenience factor. We’ve also found when making basic breads such as baguettes that instant yeast yields a cleaner, purer flavor than active dry yeast because it doesn't contain any dead yeast cells. However, in breads that contain butter, sugar, and other flavorings, we find it difficult to detect a difference in flavor between instant and active dry yeasts. It's best not to substitute one type of yeast for another, but if you must, here are the guidelines.
To substitute active dry for instant (or rapid rise) yeast: Use 25 percent more active dry. For example, if the recipe calls for 1 teaspoon of instant yeast, use 1 1/4 teaspoons of active dry. And don't forget to proof the yeast, i.e. dissolving it in a portion of the water from the recipe, heated to 105 degrees.
To substitute instant (or rapid rise) yeast for active dry: Use about 25 percent less. For example if the recipe calls for 1 packet or 2 1/4 teaspoons of active dry yeast, use 1 3/4 teaspoons of instant yeast. And you do not need to proof the yeast; just add it to the dry ingredients.
