I was listening to an episode of @StillTalkingPodcast . They were talking to a guy from Lallemand yeast. He mentioned that Osmotic stress on the yeast is less when the grain is not yet fully converted, or that the long dextrin chains create less stress than short chain converted glucose, and is less prone to infection.
That being said, do you think it is better to do a shorter rest on your dextrin conversion, and let more of conversion happen in the fermenter than in the mash tun? I do a half hour rest at 130-140F with giuco-amylase. I've heard others doing everything from basically no rest to over an hour.
I've tried that and the results were disappointing. I've found the most success at a one hour rest period.
Agree with Glenlyon. We are pretty much using the protocol recommended by our enzyme sales guy. My recommendation is for you to do the same. Explain your grain bill, your batch size and your final product you are making, and they should have lots of information to optimize your results. Sales of their enzymes require their customers are happy with their results so they generally are very on point. We are running a 26 gallon mash of 70% corn and getting 19-20 brix at pitch, and 4 days later we are sitting at 2 brix. So 10% mash. Just what we want.
I'm finishing out at .5 Plato with the half hour rest, and with the grain bill I'm using it may not be possible to finish out to zero. I tried an hour rest and it finished the same, but there were some other variables at play as well. I'll continue to play with it, but I was asking more for the sake of theory. Thanks for the input.