Yeast, a microorganism that consumes sugar to produce carbon dioxide and alcohol, is a very important part of many baked and brewed products. "Development" is a simple process to test if the yeast is on or off, as well as to make the yeast work faster. Modern techniques for packaging yeast have made this process less necessary, but development is still a good idea for yeast that has been sitting on the shelf for a long time.
Step
Method 1 of 2: Developing Active Dry Yeast
Step 1. Skip this whole process if you are using instant yeast
Instant yeast, or "fast-spreading" yeast types with smaller grains, do not need to be expanded and can be added directly to dry ingredients. Instant yeast is always active and can be stored for a very long time. Some professional bakers think that instant yeast and active dry yeast produce a worse taste than fresh yeast, but others don't notice any difference in the final result.
never ever use brewer's yeast, champagne yeast, or wine yeast for baking.
Step 2. Measure out a small amount of water or milk
Pour a small amount of water or milk into a heat-protected container, writing down the amount you are using. The exact amount doesn't matter, but you'll need to subtract this amount from the amount of liquid in your recipe. 1/2 cup (120 ml) should be more than enough for a regular bread recipe.
For example, if you used 1/2 cup (120 ml) of water to develop the yeast, and the recipe calls for a total of 1 cup (240 ml) of water, then only use 1/2 cup (120 ml) of water because you will be mixing the remaining 1/2 the glass (120 ml) with yeast
Step 3. Warm the liquid
Warm the liquid to 105-110ºF (40–43ºC), a warm temperature but not hot or steamy. While yeast works best at slightly lower temperatures, active dry yeast requires a little extra heat to start working.
If you don't have a food thermometer, warm the liquid until it's moderately warm (lukewarm), leading to a low temperature. A slightly cooler liquid will take longer to activate the yeast, but if it is too hot, the yeast will die and will not activate at all
Step 4. Mix in one teaspoon (5 ml) of sugar
Only warm water is needed to activate the yeast, but the sugar allows you to test if the yeast is ready or not. The ready yeast will eat the sugar and produce carbon dioxide and other substances, which is the process that makes bread dough rise and gives it its unique taste. Stir the sugar quickly until it dissolves.
If you forgot to add sugar, you can add sugar after the yeast is in the water. This method is equally effective, but you'll need to stir more gently to avoid spilling the yeast or damaging the yeast
Step 5. Sprinkle yeast over the liquid
Measure out the amount of yeast the recipe calls for and sprinkle the yeast over the liquid. If the recipe calls for fresh yeast, use 1/2 times the amount of active dry yeast as dry yeast is more concentrated. If the recipe calls for instant yeast, use 1.25 times the amount of active dry yeast.
Note that some types of yeast expand when added to water. Transfer to a larger container, if necessary, to avoid spilling during this process
Step 6. Stir in the yeast after 30–90 seconds
As the yeast sits on the surface of the water or slowly sinks in, the water will dissolve the inactive yeast layer and free the active yeast in the center. After letting this happen for a while, gently stir the yeast in the water.
There is no need to calculate the time required for this step precisely. The chances for the yeast to be affected by stirring are very low, even if you stir it immediately
Step 7. Wait ten minutes, watching for bubbles or froth
If the yeast is alive and active, it will start consuming sugar and releasing carbon dioxide, the gas that causes bread to rise. If the surface of the mixture becomes foamy or bubbly, the yeast is active and can be added to other ingredients according to your recipe.
- You may have to pay close attention to the bubbles around the rim of the bowl.
- Other signs of this activity include a readily recognizable "yeast" odor or an expanding volume, but this volume is not always easily recognizable.
- Unfortunately, if the mixture doesn't foam, it's very likely that the yeast is dead and can't be used in the recipe. You can probably add a little warm water, no hotter than 115ºF (43ºC), and let it sit for 10 minutes. If the yeast hasn't foamed after 10 minutes, throw it away.
Step 8. Add the liquid yeast mixture when the recipe calls for yeast
Add the yeast-containing liquid mixture when the recipe instructs you to add yeast. Don't strain the yeast.
Method 2 of 2: Developing Fresh Yeast
Step 1. Check for problems with fresh yeast
Fresh yeast refers to yeast that is stored in a slightly wet form and packaged together, thus keeping it active but not as durable as yeast packaged in modern dry yeast packaging methods. Note that fresh yeast is unlikely to survive freezing air, and will only last a week or two at room temperature, or one to three months in the refrigerator at most. If the yeast becomes hard or turns dark brown in color, it's most likely unusable. You can still test it by expanding it to be sure, but it would be wise to purchase additional spare yeast beforehand so you don't have to stop your baking process.
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Notes:
Fresh yeast is also known as baking yeast or wet yeast.
- never ever confused between liquid brewer's yeast and fresh baker's yeast. Only use fresh baker's yeast (in any form) for baking.
Step 2. Measure a small amount of water or milk into a heat protected container
Measure out 1/4 cup (60 mL) of the liquid instructed in the recipe you want to follow. You can use more liquid if you need a lot of yeast, but be sure to note how much yeast you use so you can subtract this amount of liquid from the recipe.
For example, if a recipe calls for 1 cup (240 mL) of milk, and you use 1/4 cup (60 mL) of milk to develop the yeast, then add only 3/4 cup (180 mL) of milk to the yeast mixture later
Step 3. Warm the liquid
Warm the liquid slightly, to 80-90ºF (27 – 32ºC), which is the temperature that promotes maximum yeast activity. Fresh yeast is already active, doesn't sleep like dry yeast, so you don't have to warm the liquid again to "wake up the yeast."
- This temperature is only slightly warm. Steam or the formation of a film on top of the milk indicates that the liquid is too hot and could kill the yeast.
- Since fresh yeast already contains moisture, you don't technically need any additional water. Water is recommended in most cases because the room temperature may not be warm enough for the yeast to expand. However, if the room is warm, you can mix the sugar and yeast right away.
Step 4. Mix in one teaspoon (5 ml) of sugar
Yeast absorbs almost any kind of sugar, so mix in a little white sugar, brown sugar, or any sugar that's natural and sweet. Artificial sweeteners cannot be used to develop yeast of any kind.
Step 5. Add yeast to the liquid
Gently stir in the amount of fresh yeast the recipe calls for. Since fresh yeast contains some liquid ingredients as well as yeast, you'll need to adjust the amount used if your recipe uses a different type of yeast:
- If the recipe uses active dry yeast, use twice the stated amount of fresh yeast.
- If the recipe uses instant yeast, use fresh yeast 2.5 times.
Step 6. Wait a few minutes and watch for bubbles
If foam or bubbles form within 5 or 10 minutes, then the yeast is alive and active, and the mixture can be added when the recipe instructs the use of yeast. On the other hand, if no foam or bubbles form (assuming the liquid isn't too hot or cold), then the yeast is most likely dead and should be discarded.
Because fresh yeast is always active, fresh yeast doesn't take as long to rise as dry yeast does
Tips
- If you're making dough, you can expand the yeast in the same container you used to prepare your dry ingredients. Just make a hollow in the flour or food, and use it as if it were a regular bowl.
- As for sugar, almost anything that contains chemical sugars (sucrose, fructose, etc.) and contains little or no acid, can be used: brown sugar, white sugar, sugar syrup, or fruit juice can be used. Artificial sweeteners cannot be used.
- As the yeast expands, it may give off an odor like ale or bread. This is normal.
- If you're on a tight baking schedule and your yeast has been around for a long time, you might want to develop a test cup of yeast before you start baking. So, if the yeast fails to rise, you'll have time to go to the store and buy another pack of yeast.
- Light can destroy yeast. This is why many bread recipes recommend keeping the dough in a covered bowl.
Warning
- Don't add yeast to water that feels cold like ice or hot to the touch. The water can kill the yeast, or at least make the yeast fail to activate.
- Salt can slow down yeast activity, or even kill it in high concentrations. Add any salt in the recipe to the other dry ingredients, not the bowl containing the yeast mixture, even if the recipe instructs you to add salt to the yeast mixture.
- Temperatures below 50 degrees Fahrenheit (10ºC) will inactivate the yeast, and temperatures above 140 degrees Fahrenheit (50ºC) will kill the yeast.
