Paul;
When using a VCM all types of dry yeast must be pre-hydrated before adding it to the mixer. The very short (60 to 90-second) mixing time is not sufficient to get the yeast well dispursed throughout the dough mass. Even compressed yeast should be pre-suspended for use with a VCM. As for adding ADY without prehydrating it, sure, it will work, but it won’t work as well as it would if you had prehydrated it, in my shop I would want the most out of my ingredients as possible, and I would want the most dough consistency I could get. These can only be had by using ADY or IDY, for that matter, according to the manufacturers directions. Yes, it does make a difference if you don’t get back to it right away. The yeast cells will actually begon feeding upon themselves, in the process releasing glutathione, which can result in unwanted dough softening, or less than optimum yeast/dough performance. It sounds like you might be better served with IDY. With the IDY you will need to pre-hydrate the yeast in 95F water (use a thermometer), but the prehydration time is only 5-minutes, so you can begin hydrating the yeast first, before you begin weighing out the other ingredients, then, by the time you’re finished weighi8ng the ingredients, the IDY should be ready to go. Keep in mind that IDY, just like ADY, or even compressed yeast, once put into warm water, must be added pretty close to the specified time for optimum performance.
Tom Lehmann/The Dough Doctor