After 5 or 10 minutes, the yeast should begin to form a creamy foam on the surface of the water. That foam means the yeast is alive. You can now proceed to combine the yeast mixture with the flour and other dry ingredients in your recipe.
A healthy activated yeast will start to pop to the top and bubble. After about 10 minutes, the top of the water should be foamy, frothy, and smell slightly of wheat or beer.
If the mixture isn't bubbly, the yeast is no longer good. Dump out your mix, and start with fresh yeast. Unfortunately, there's no way to revive old yeast.
After 10 minutes, the mixture should be bubbly. Once you've proved the yeast is alive, go ahead and add it to your recipe – reducing the water in the recipe by 1/4 cup.
To proof yeast, mix ¼ cup of the liquid stated in the recipe with the amount of yeast on the ingredient list in a small bowl. Let it stand at room temperature for 10 – 15 minutes or a little longer on cold days. You should see a foam growing on the surface of the liquid.
What is this? Dead yeast will look yellowish or brownish in water. When yeast is first added to water, it will sink to the bottom of the container. After a few minutes, you may see bubbles rising to the surface as the yeast consumes the sugar in the water.
In three to four minutes, the yeast will have absorbed enough liquid to activate and start to foam. After ten minutes, the foamy yeast mixture should have risen to the 1-cup mark and have a rounded top. If this is true, your yeast is very active and should be used in your recipe immediately.
To proof yeast, you dissolve the yeast in warm water with sugar and wait until it's creamy-looking with many small bubbles, which indicate the yeast cells are doing their thing.
Regardless of the type of yeast you use, if your water reaches temperatures of 120°F or more, the yeast will begin to die off. Once water temps reach 140°F or higher, that is the point where the yeast will be completely killed off.
Without being “active,” the yeast cannot eat the sugars, and therefore you will not get those gasses that are the key to the entire bread-making process. Thus, we have to make sure our yeast is still alive before we start making our dough, so that we get the maximum rise out of it.
Within 24-36 hours, carbon dioxide normally starts bubbling through the airlock, as long as everything is working correctly and if the fermenter is sealed properly. Fermentation can take as little as 3 days if you are using a fast-acting yeast and the temperature is ideal.
For the first 12 to 24 hours, you won't see much (if any) activity in the airlock. The yeast is taking this time to gather its strength and multiply its numbers. For the next 1 to 3 days, you'll start to see bubbles popping rapidly up through the airlock.
Yeast: Active dry yeast lies dormant and needs a warm liquid to become “activated.” Instant yeast, also known as quick-rise or rapid-rise yeast, does not need to be activated or “bloomed” before using. It's ready to go as-is and simply gets incorporated right into your dry ingredients.
A small amount of room-temperature or slightly warm water works best. Once foamy, stir it with a spoon or a fork until the yeast is completely dissolved. It should be smooth and silky and you can carry on with the rest of the recipe. You do not need sugar to activate the yeast.
If the water is cold, the yeast still produces carbon dioxide gas, but at a much slower pace. Bakers sometimes let dough rise in the refrigerator for one to three days. Because the yeast works slowly at cold temperatures, it has more time to create lots of special molecules that add flavor to the dough.
While there's some downside to using water that's a little too cool for the yeast, water that's too warm—between 130 and 140°F—is fatal to yeast.
The warm water dissolves some of the food in the granules and warms the yeast up to a temperature which is favourable to fermentation.
Step 1: Perform the fingertip test to make sure your dough is overproofed. The test involves gently pressing your finger into the surface of the dough for 2 seconds and then seeing how quickly it springs back. The dent you make will be permanent if the dough is overproofed.
“If the dough has risen too long, it's going to feel fragile and might even collapse as you poke it,” says Maggie.
If the yeast doesn't foam or it only makes a few bubbles, then it means that it won't be capable of making the dough rise, which makes it useless. The foam is the indicator that the yeast is alive and ready to make some dough magically rise and take the needed shape for baking.
Active Dry Yeast
If the yeast is still alive, it will begin to foam and grow within a few minutes.
If you accidentally add too much yeast to your dough, the yeast will make the dough rise too quickly. This will cause the glutens of your flour not to develop entirely, causing your dough to become overly sticky. For yeast to develop and release CO2, it makes your dough rise and gives it bubbles and structure.
If the yeast doesn't get foamy or bubbly, either the water is too hot and killed the yeast or the yeast is no longer active. Toss old yeast that doesn't activate and use new yeast for your recipe. The shelf life for unopened dry active yeast is usually about twelve months.