Montana Public Radio

Baking Yeast: Which Kind Do You Knead?

Jan 26, 2020

The Food Guys react to a March 2018 post published at the Serious Eats blog by cookbook writer Stella Parks (BraveTart: Iconic American Desserts) titled "All Abouty Dry Yeast: Instant, Active Dry, Fast-Acting and More." 

On the topic of sourdough starter - a propagated version of wild yeast that seems to develop by magic, from thin air - Greg Patent points out: "There is yeast all around us. It's also on the surface of fruits. We're breathing it right now, John."

Wonders of the microscopic, ubiquitous fungus Saccharomyces cerevisiae aside, sooner or later, a baker's gonna need some store-bought yeast. From Parks's blog post, here's the rundown of types of baking yeast available to home bakers in 2020.
 

1. Active Dry Yeast:

"As the name suggests, active dry yeast must be "activated" by dissolving the granules in warm water, according to the package directions. (The specifics can vary from brand to brand; some may call for sugar to be added as a fuel for the yeast.)

If the yeast is still alive, it will begin to foam and grow within a few minutes.

Active dry yeast is so unstable that any given packet may well be dead, so it's important to verify whether or not it's alive before proceeding with the recipe—even if the yeast hasn't yet reached the expiration date printed on the package. Active dry yeast also has a comparatively large grain size, further necessitating direct contact with warm water to dissolve. Due to this time-consuming step, as well as the high risk and cost of failure, active dry yeast is rarely used in a professional setting.

The Basics

  • Active dry yeast is highly perishable; always check the expiration date before use.
  • Potency can vary over time, producing inconsistent results
  • Must be rehydrated before use
  • Easily damaged by liquids above 115°F (46°C)
  • Suitable for recipes that require more than one rise
  • Suitable for cold-proofed doughs
  • To use in place of instant yeast, activate according to package directions, using a portion of milk or water from the recipe rather than additional liquids.

2. Instant Dry Yeast:

Thanks to its unique manufacturing process, instant yeast is guaranteed to be 100% active, so it's ready for use straight from the package, and its behavior is consistent over time. Due to its small grain size, instant yeast will readily dissolve in the ambient moisture of a dough, eliminating the need for rehydration. Given its stability and shelf life, instant yeast is safe to buy in bulk, dramatically lowering its cost compared with the tiny packets of active dry yeast sold in stores.

The Basics

  • Extremely stable; can be frozen for several years
  • Consistent behavior over time
  • Tolerant of temperatures up to 130°F (54°C)
  • Suitable for recipes that require more than one rise
  • Suitable for cold-proofed doughs
  • My favorite brands: SAF Red Label, Dr. Oetker
  • To use in place of active dry, incorporate directly into the dry ingredients. Add any ingredients used for proofing (warm water, sugar) to the dough along with other liquid ingredients.

3. Fast-Acting Instant Yeast:

As a subcategory of instant yeast, fast-acting yeasts are likewise stable and easy to use, but formulated to operate on an accelerated timetable, making them unsuitable for recipes that require a long rise. Whether you're using RapidRise (from the Fleischmann's brand) or Quick-Rise (from Red Star), it's important to remember that these yeasts are defined by their trademark rather than by some objective measure, so their behaviors can vary wildly.

The Basics

  • Highly stable; can be refrigerated up to one year
  • Consistent behavior over time
  • Tolerant of temperatures up to 130°F (54°C)
  • Designed to work with only one rise
  • Not suitable for refrigerated doughs
  • Not suitable for doughs with a long, slow rise
  • To use in place of instant dry yeast, proof at cool room temperature, and follow the recipe's visual cues (such as letting the dough double in bulk) rather than a specific timetable. To use in place of active dry yeast, incorporate directly into the dry ingredients. Add any ingredients used for proofing (warm water, sugar) to the dough along with other liquid ingredients.

4. Bread Machine Yeast:

Like other types of instant yeast, bread machine yeast doesn't need to be dissolved before use and keeps well in the fridge or freezer. As its name implies, this style is designed for use with a bread machine and works best under those specific conditions. It can be used with reasonable success in recipes that call for instant yeast, though it will not produce as vigorous a rise in refrigerated doughs.

The Basics

  • Highly stable; can be refrigerated up to one year
  • Consistent behavior over time
  • Tolerant of temperatures up to 130°F (54°C)
  • Designed for use in recipes formulated for bread machines
  • Not as energetic in refrigerated doughs

Experienced bakers can successfully substitute one type of yeast for another with a few tweaks, hydrating active dry for use in a recipe that calls for instant, or using RapidRise to shorten the proofing period of a slow-fermented dough. But for beginners, the best course of action is to find the right yeast for the job, knowing that not all types of dry yeast can be used interchangeably or produce equally good results on a 1:1 basis."

(Broadcast: "The Food Guys," 1/26/20. Listen weekly on the radio at 9:53 a.m. Sundays, or via podcast.)