I'm here typing this in my 91F office, spent the night at a local motel and just stopped to check e-mail. For its impact upon Aw it doesn't matter if a granulated sugar or liquid sugar is used, in that respect they all perform equally, the only reason why the commercial manufacturers use HFCS is because of price and convenience (it's easier to convey and meter a liquid sugar than a granulated sugar). You're right about the "dead yeast" since all yeast ends up being dead as a result of baking the dead yeast can be added to the dough and just lumped under "yeast" on the label. This helps them with the appearance of a cleaner label.....who wants to see something as chemical sounding as L-cysteine/L-cysteine hydrochloride? As for adding IDY later in the dough mixing procedure for home bakers, it can be done only if they have a mechanical mixer and it is interacting with the dough in the correct manner (I have found that this is seldom the case with home bakers) because of this I have always recommended to home bakers/pizza makers/frozen dough makers, that the IDY be added right on top of the flour, it just circumvents so many of the variables that can exist with the home mixers. To put it another way, I've never seen a machine mixed dough fail because the yeast was added on top of the flour, but I've seen any number of cases where the dough showed less than spectacular performance because the yeast was added late in the mixing stage, reasons being, it was added too late, it was not thoroughly incorporated into the dough due to poor mixing action, oops...forgot to add the yeast. I recently saw a case where the dough was mixed with a "J" hook and the IDY was added late in the mixing stage. The incorporation of the IDY was so poor that I think I could have picked out all of the particles of IDY from the dough if I had time to do so. So why not just add the yeast sooner? The truth of the matter is if the IDY was added any sooner it would be more convenient to just add it to the dry flour and we have found that when poor mixing action is the cause for poor yeast incorporation longer mixing times are not the answer.
As for ascorbic acid, there might be some benefit but the ROI wouldn't be worth it, not with a dough that will be used within 15-days of preparation. Some of our readers might remember Pizza Magia (Cincinnati, OH) pizza chain, I developed their frozen dough formulation and dough management procedure that was used by their commissary to provide frozen dough balls to all of their stores, we used static freezing but we also included ascorbic acid to provide a supplemental level of insurance against dough failure should a store fail to use the dough within the 15-day prescribed window of use time. In such a setting where we made A LOT of dough balls, and used them under different conditions (every store interpreted the ops manual differently) and there were about 100 stores, I can't ever recall having a massive dough failure, a few complaints from some of the stores yes, but never a failure of the dough itself where many dough balls were affected. Most of the complaints we received were due to poor management of the dough at the store, such as slacking out too many dough balls and putting the unused ones back into the freezer or putting the slacked out and warmed (50F) unused dough balls back into the cooler for use on the following day......don't know why, but all of a sudden the dough balls are blowing! Right! Refer to ops manual, page 13, that should resolve the problem. I call it a self inflicted problem.
BTW: We also have an older, less energy efficient chest freezer that doesn't have an automatic defrost cycle and I agree with Norma that it's the best thing since sliced pizza when it comes to holding my frozen pizza dough. For home use I can often get three, sometimes four weeks of decent performance from my dough when held in this freezer but do not try this if you are in a commercial setting of any kind, failure is simply not an option, when dough fails due to a freezer temperature/defrost (we like to call it temperature abuse) problems everything in the freezer goes south all at once, and don't forget that temperature abuse in a commercial setting doesn't end at the freezer, it still happens throughout the entire distribution chain (that's why we used ascorbic acid in the P.M. frozen dough) but you won't know it until the store begins to report back to you that all of the dough is failing.....not a pretty picture.
Tom Lehmann/The Dough Doctor