Yeast is a critical ingredient in baking that allows dough to rise. Active dry yeast is the most common form of yeast used in home baking. It comes in small packets or jars and needs to be activated in warm liquid before being mixed into dough. Understanding yeast equivalents helps bakers substitute amounts in recipes.
The Different Forms of Yeast
There are several different forms of yeast available:
- Active dry yeast – Granules of live yeast that need to be dissolved in warm liquid to activate before mixing into dough. Sold in packets or jars.
- Instant yeast – Finer granules that don’t require proofing in liquid first. Can be added directly to dry ingredients. Also called bread machine yeast or rapid rise yeast.
- Fresh yeast – Sold in cakes or blocks and needs to be used quickly. Harder to find than dry yeast.
- Quick rise yeast – Leavening agent combined with dough enhancers. Produces faster rise.
Active dry yeast is the most widely available and commonly used for baking bread. It lasts longer than fresh yeast so it’s handy to keep on hand. The packets conveniently contain a measured amount of yeast suited for most standard bread recipes.
Active Dry Yeast Packets
In the United States, a standard packet of active dry yeast contains 2 1/4 teaspoons of yeast. This quantity is enough yeast to leaven approximately 4 cups of flour.
One packet equals:
- 2 1/4 teaspoons
- 1/4 ounce
- 7 grams
Some common US brands including Red Star and Fleischmann’s sell their yeast in packets that contain this amount. Be sure to check the packet instructions though, as some specialty yeast packets may contain slightly different quantities.
Converting Packet Yeast to Other Units
It’s easy to convert the amount of yeast from a standard packet to other units for measuring:
- 1 packet (2 1/4 teaspoons) = 3/4 of a tablespoon
- 1 packet (2 1/4 teaspoons) = 1/2 of a 1/4 ounce package
- 1 packet (2 1/4 tsp) = about 22 grams
Knowing these conversions allows you to substitute other units of yeast for the amount in a packet when necessary. It’s preferable to use measurements by weight rather than volume for the most consistent results.
How Much Yeast to Use
The appropriate amount of yeast to use depends on the type of dough and desired rise time. Lean doughs with only flour, water, yeast and salt require more yeast than enriched doughs containing eggs, oil or sugar. The other ingredients and kneading method impact how quickly the yeast can produce gas and raise the dough.
For a standard loaf of bread, most recipes call for:
- 2 1/4 teaspoons (1 packet) yeast for 2-3 cups flour
- 1 tablespoon yeast for 6-8 cups flour
- 1 tablespoon + 1 teaspoon yeast for 10-12 cups flour
However, amounts can vary depending on the recipe. Quick breads like soda bread with chemical leaveners instead of yeast require less, usually 1 teaspoon yeast per 4 cups flour.
Instant Yeast Substitution
Instant yeast contains smaller yeast granules so more can fit in a given volume. It’s more concentrated than active dry yeast. Use 25% less instant yeast when substituting it in a recipe.
Convert active dry yeast as follows:
- 2 1/4 teaspoons active dry yeast = 1 3/4 teaspoons instant yeast
- 1 tablespoon active dry yeast = 3/4 tablespoon instant yeast
Fresh Yeast Substitution
Fresh yeast is sold in compressed cakes or blocks so it equals a greater volume than dry yeast. Use 40% less fresh yeast when substituting it in a recipe.
Convert active dry yeast as follows:
- 2 1/4 teaspoons active dry yeast = 1 1/3 teaspoons fresh yeast
- 1 tablespoon active dry yeast = 2 teaspoons fresh yeast
Quick Rise Yeast Substitution
Quick rise yeast is designed for speedier rising. Use 25% less quick rise yeast when substituting it in a recipe.
Convert active dry yeast as follows:
- 2 1/4 teaspoons active dry yeast = 1 2/3 teaspoons quick rise yeast
- 1 tablespoon active dry yeast = 3 teaspoons quick rise yeast
Activating Yeast
Active dry yeast needs to be dissolved and activated in warm liquid before mixing into dough. This activates the live cultures and ensures the yeast is evenly distributed.
Follow these steps:
- Heat liquid ingredient called for in recipe (typically water or milk) to 110-115°F. Do not exceed 120°F or the yeast will be killed. Sugar can also be added to the warm liquid.
- Stir in yeast until fully dissolved, no more than 10 minutes.
- Let stand for 5-10 minutes until foamy, indicating the yeast is activated and alive.
- Add yeast mixture to dry ingredients and proceed with recipe.
The foaming action verifies the yeast is active and ready to start multiplying and creating carbon dioxide bubbles to leaven the dough.
Proofing Yeast
Proofing tests yeast activity. Sprinkle a pinch of yeast over warm water with a teaspoon of sugar. It should become creamy and foamy after 5-10 minutes if the yeast is fresh and viable.
If using active dry yeast in a bread machine, proofing isn’t necessary. The machine’s kneading action evenly distributes the yeast once activated by the warm liquid mixing in.
Storing Yeast
Proper storage extends the shelf life of yeast. Keep yeast in an airtight container in the refrigerator. At room temperature, yeast will start to lose potency after a couple months. Refrigerated, it can last 6 months to a year before the lively activity declines. Active dry yeast can also be frozen for even longer storage of up to 2 years.
Check expiration dates and be aware a longer storage time means the yeast may need a little more time to proof and foam up. Old yeast may require slightly warmer water or an extra teaspoon when activating it to ensure the yeast is lively enough.
Signs of Bad Yeast
Yeast naturally has a short shelf life. Signs that yeast may be expired or bad include:
- Does not dissolve or foam up properly when activated
- Dough does not rise
- Alcohol or solvent odor instead of yeasty, malty smell
- Change to grayish or dark color instead of beige or light brown
Outdated or inactive yeast can prevent bread dough from rising properly. It’s best to discard old yeast that shows any of these signs and use fresh yeast instead.
Killing Yeast with Heat
Excessive heat can kill yeast, preventing it from leavening dough. Yeast is temperature sensitive and optimal activity occurs between 70-110°F. Higher temperatures outside this zone hinder the live cultures:
- 120°F – yeast growth declines
- 130°F – yeast is inactivated
- 140°F – yeast is killed
When proofing or activating yeast, use properly heated liquid between 110-115°F. Be aware that excessive mixer speeds can make dough too warm and kill yeast action. Make sure all ingredients for dough are at room temperature, not warmed above 80°F.
Temperature Effects on Yeast
The growth rate of yeast increases along with temperature up to its peak around 86°F. Warmer temperatures cause the yeast to be more active and generate carbon dioxide faster.
Cooler temperatures below 60°F slow down the activity. The yeast will still leaven the bread but at a slower pace. Adjustments may be needed in ingredients, rising time or baking temperature to account for slower proofing.
Freezing temperatures stop yeast growth entirely. Dough can be refrigerated to slow down proofing for up to 24 hours but the yeast won’t create any rise when frozen.
Altitude Effects on Yeast
Higher altitudes affect yeast performance. The lower air pressure causes dough to rise faster and over-proof. To compensate, use less yeast at higher altitudes – about 3/4 of the amount called for in a recipe at sea level.
Here are some general yeast adjustments for high altitude baking:
| Altitude | Active Dry Yeast Adjustment |
|---|---|
| 3,000 feet | No adjustment needed |
| 3,000 – 6,000 feet | Use scant 2 1/4 teaspoons (just under 1 packet) per 4 cups flour |
| 6,000 – 8,000 feet | Use 2 teaspoons per 4 cups flour |
| 8,000+ feet | Use 1 3/4 teaspoons per 4 cups flour |
The less dense air and lower atmospheric pressure causes faster rising. Using less yeast prevents over-proofing at high altitudes.
Fixing Bad Bread with Yeast Issues
Sometimes bread comes out with too many holes or tunnels, a dense texture, or flat shape when it doesn’t rise sufficiently. The problem is likely due to the yeast. Here are some common causes and solutions:
- Too much yeast – Use less yeast, allow for shorter rise time
- Too little yeast – Use more yeast, allow for longer rise time
- Old yeast – Use fresh yeast and properly proof/activate it
- Water too hot – Don’t exceed 115°F when activating or proofing yeast
- Didn’t proof yeast – Always check for foam to ensure yeast is active
- Rising area too cold – Raise temperature to 70-80°F range
Controlling the yeast activity makes a big difference in achieving a nice even rise and light texture in breads.
Conclusion
When baking bread, the type and amount of yeast has a major impact on rise time and texture. Understanding how much a standard packet of dry yeast contains and how to convert it for recipes allows bakers to easily substitute amounts.
One packet of active dry yeast equals 2 1/4 teaspoons. Use about 1 packet (or 2 1/4 tsp) of yeast per 4 cups of flour. Check equivalents when substituting other forms like instant, fresh or quick rise yeast.
Activating yeast properly in warm liquid ensures it is bubbly and active for leavening bread dough. Controlling temperature and allowing for altitude adjustments also affects yeast performance for an ideal rise.
