Thanks Kirem,
I really have to keep a more regular eye on Kai's site. It's just a great way to kickstart studying a particular aspect of brewing science.
One thing we do at CUB that ties in with Kai's research, involves the tie between pH, alpha acid isomerisation and protien coagulation. We do something really basic, which I emulate at home to try and optimise both.
Calcium levels in the boil contribute to pH drop when the calcium complexes with phosphates and drops out of solution... higher levels of Calcium lead to rapid reduction in boil pH. But that interferes with hop utilization. Solution - reserve some of your calcium addition for half way through the boil. By about 30mins in.. the majority of your isomerisation has already happened, and its done so at a relatively high and therefore effective pH - chuck in some calcium salts, the pH drops and then for the remainder of the boil, protein coagulation and flocculation happens at a more optimal low pH. This also increases the amount of calcium actually carried over to the fermenter (yeast health and pH reduction of beer during fermentation) as an addition to strike water is largely lost during the mashing and boiling stages.
The BrewKaiser site is really top stuff and I recommend all homebrewers reserve a quiet afternoon for a good read.
TB
