Active Dry Yeast
Active dried yeast (ADY) is yeast in powder form consisting of millions of dehydrated single-celled organisms. When brought into contact with water, these micro-organisms begin to feed on the sugar and starch in the dough, producing carbon dioxide and alcohol. This is what makes your dough rise.
When you take the yeast out of the package, it is not active. To activate the yeast, you need to dissolve it in water and allow it to activate before adding it to the flour. Simply dissolve the yeast in a small amount of warm water. Once dissolved, the yeast will need a few minutes to become active.
If you do not want to wait to activate yeast, use its brother instant dry yeast (IDY). This type of yeast can be added directly to flour. When substituting ADY with IDY, a good rule is to use 25% less IDY than the amount of ADY you are replacing.
Active dry yeast should be stored in a cool, dry place.
Yeast is not a big fan of salt, so when you make your dough keep the two of them separated. Start making your dough by dissolving salt in water, then stir in 10% of your flour before adding the yeast. This small amount of flour will act as a buffer between the salt and the yeast. At this point, you are ready to add the rest of the flour and knead your dough.
ADY loses its potency when stored incorrectly or when stored after the expiration date. It is not recommended to store ADY in the fridge as this will lead to condensation over time, which ultimately has an adverse effect on the performance of the yeast.
Since temperature is the #1 driver of fermentation, it is very important to use the right temperature for yeast fermentation. For ADY the optimum water temperature ranges between 32˚C-35˚C (90˚F-95˚F).
Temperatures hotter than 46˚C (115˚F) can seriously damage the yeast, so use with caution.