A while back, one of our members, jeancarlo, who recently opened a pizzeria in El Grullo, Mexico, asked for advice on par-baking of crusts. I provided him with the following excerpts (in italics) from materials written by Tom Lehmann:
Potato flour has been used successfully in pizza crust production, especially par-baked thick crusts to help improve the overall quality of the par-baked crust. It also imparts some crust color so you will most likely need to reduce the sugar level a little when using potato flour. As to the amount of potato flour to use, I'd go with 5% of the flour weight and also increase the dough absorption by about 4% at the same time. (Pete-zza's note: I assume increasing the dough absorption means increasing the hydration by 4%.)
I think one of the best deep-dish crusts that I've ever had is a par-baked crust…..I made my dough with 10% potato flour in it. I had to increase the dough absorption by almost 8% to compensate for the drying effect of the potato flour. I then pan proofed the dough for 45 to 60 minutes at room temperature. I then par-baked the dough/crust at 400 F in a deck type oven. The baking time was approximately 5 minutes. Just bake the crusts until they're set, but not browned. On the following day, I dressed the crusts and baked them at 450 F for about 18 minutes. The finished crusts were extremely tender eating, some here at the AIB say they eat like cotton candy. That's my take on it, you may or may not like that kind of crust. A little experimenting should give you the crust characteristics that you are looking for.
Jeancarlo subsequently asked whether it was possible to use potato flakes (the type sold in supermarkets) rather than potato flour. The answer I gave him after researched the matter was as follows (also in italics):
If you can get potato flour that would be better. You might be able to use the dehydrated potato flakes that are sold in supermarkets and used to make mashed potatoes, but one of the problems with those products is that they usually include sodium bisulfite. The sodium bisulfite is used to prevent browning. However, in a dough it slows down the yeast activity. If you decide to use the dehydrated flakes anyway, you might try adding a bit more yeast to compensate for the slower yeast activity. If you find you need a bit more color in the crust, which the potato flour would do, you might add a bit of sugar to your recipe or increase it a bit if your recipe already has it. You might also give some thought to pulverizing the potato flakes if you use them, to get them in a finer, maybe more usable form. I would use a food processor. I don't know if that will help or hurt, but it might be worth trying as a simple experiment. Maybe you can try it both ways.