Decoction schedules are adjusted to the degree of modification of the malt and towards the desired beer style.
There is a pH drop, but it won't be as drastic as from 5.5 to 5.2. I observed a drop of 0.1 usually.
Decoctions speed up the sparge process since a clear run is obtained earlier. It already boiled off some proteins and a large portion of that protein break remains in the sparge tun.
Despite what the amateur press says, tannin extraction during decoctions are a real concern. Usually this is handled by discsrding 30% of the husk or an all out Spelzenmaischverfahren.
For wheat beers the decoction boils assist in further breaking down the stubborn wheat - another alternative is to double mill at increasingly smaller grind settings.
Of course, the decoction must be returned into a mash with enough enzymes to convert the extra starches. Starches are not freed endlessly. On a triple decoction schedule the third decoction achieves very little in this respect and is thus either thin or normal, but rarely ever thick (1:2 ratio)Statistics: Posted by Weizenberg — Sat Feb 13, 2016 1:39 pm
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