Originally Posted by AnOldUR
Is this speculation or proven fact? Can’t the enzymes survive when exposed to heat for a short amount of time? And even if “some” of the enzymes are denatured will their absence have any effect on the mash? By personal experience and from the number of brewers who go with grain to water this statement can probably be stamped as “myth.”
Pure speculation. I don't expect it to be much though and in many (maybe even most) cases to be negligible. When I said 'enzymes' I should have said 'beta-amylase enzyme' since it's the enzyme that affects fermentability most.
As far as 'stamped as myth' I guess I thought just the opposite; i.e. that it should be very apparent that this would be the case. Maybe not to a large degree in most cases but still seems extremely apparent.
Think about why a mash @ 152* F will yield a more fermentable wort than 154* F. Both temps are above the 'range' for beta-amylase and beta will become denatured at either temp over a certain period of time
. But it denatures more slowly at 152* F so the beta has more time to act and you get a more fermentable wort. It seems that doughing-in high and letting the temp decrease (i.e. grain-to-water) vs. doughing-in low and letting the temp increase (i.e. water-to-grain) should be enough of a difference to have an effect on the beta and thus the fermentability.
But again it's not like it matters, we all adjust our process to achieve our goals and hitting your target FG should be no problem either way.