A while back, I got into a discussion on the shelf life of yeast which runs from one to two years if it is properly stored. One of the men said that he had Fleischmann’s Yeast that had been in his storage for many years and because it was in a sealed can it would work just fine.
All of my friends who are into food storage know that if they find something that is very old I want to see it. The other day a friend brought me a 2lb can of Fleischmann’s active dry yeast. Now I couldn’t find a date on the can, but I can remember having owned cans like this in the 1970 and have not seen them for many years.
So I decided this would be a good time to test my friend’s idea. We opened the can and attempted to proof it according to the instructions on the Fleischmann’s Yeast website.
Their instructions. To proof yeast, add 1 teaspoon sugar to 1/4 cup warm water (100° to 110°F). Stir in 1 envelope yeast (2 1/4 teaspoons); let stand 10 minutes. If the yeast foams to the 1/2 cup mark, it is active and you may use it in your recipe.
After waiting ½ hour, the yeast was a complete failure, which was what I expected. But during the research I found a few interesting facts about yeast. First there are three types of yeast commonly sold on today’s market.
Active Dry Yeast. It’s dry, granular and about the consistency of cornmeal. To use it, you have to dissolve a few teaspoons in warm water (110-degrees or cooler) and then add it to the rest of the ingredients. This yeast will give your dough two rises.
Instant Active Dry Yeast. This is also known as bread machine yeast. This yeast is ground into finer particles and does not need to be dissolved in water like active dry yeast. You can add it directly to the dry ingredients.
This yeast will give you two separate rises and it can be used interchangeably with active dry yeast if you skip the water activation step. It is my understanding that because of the way this yeast is dried it will have a longer shelf Life than active dry yeast.
Rapid-Rise Yeast. This yeast has also been ground into smaller particles so that it doesn’t need to be dissolved into water. Enzymes and other additives are added to make the dough rise faster. With this yeast, you only require one rise of the dough.
This yeast makes bread that is bland and commercial tasting. This yeast cannot be substituted for either active dry or instant active dry yeasts.
I would recommend that if your yeast has been stored for any time you proof it prior to adding it to your ingredients. There is no sense in wasting food if the bread fails to rise.
If you are stuck with out yeast try some of the methods shown in the following links. Leavening Bread with Homemade Baking Powder., Leavening Agents for baking after TEOTWAWKI, Salt Rising Bread .Old Ways to Leaven Bread.
Hope this helps you understand more about the shelf life of yeast.