ADY should be mixed with four to five times its weight of water (100 to 105F) and allowed to hydrate for about 10-minutes, stir again, and add to the mixing bowl. I like to add the hydrated yeast to the dough water to further disperse it when making pizza dough at home, you can also rinse out the container that you hydrated the ADY in with the dough water. With IDY you have the option of adding it directly to the flour if you will be mixing the dough by machine for 5-minutes or more. If you will be mixing by hand, or mixing for a very short time, you should hydrate the IDY in four to five times its weight of water (95F) and allow to hydrate for about 10-minutes, then stir once again and add to the dough. Again, I like to add the hydrated IDY to the dough water just as I do the ADY.
Tom Lehmann/The Dough Doctor