100C v. 75C controversy
- Since at least Medieval times beer wort has been boiled. So has a mead
wort. Here are the arguments for this -
2) stops enzyme action (to retain some unfermentable dextrins)
3) drives off unwanted flavor compounds
4) caramelises sugars
5) coagulates proteins
6) concentrates wort(by evaporation)
Recipes mention boiling for at least 1 hour. It appears to me that for
the home brewer, 100C is too high and 1 hour too long, leading to
flavor loss, and using water at 75C (170F)is sufficient. This
2) retain enzymes - malt additive (adjunct)will produce necessary
dextrins for head and flavor.
3) primary fermentation drives off many flavor compounds.
4) color comes from the roasted malt already.
5) 43C is sufficient to coagulate milk curd in cheese making, 75C
should be more than adequate for a beer wort.
6) water quantity is easily managed.
Long boiling of hops is not desirable. Hops can be boiled for 5
minutes in a pressure cooker to retain volatile oils.
Many home brewers use malt extracts for convenience, their quality is
sometimes lacking and lengthy boiling will only make it worse. See:
"Malt Extracts: Quality Not Always Up to Par"
(you might need to click on 'InFerment' after entering site)
Commercial breweries do boil the wort, the boiling time depending on
the beer type. But they also contol the temperature, filter and
pasteurize the beer. Chemists monitor the process for correct levels
of sugars, hops and proteins.
Just as an overcooked vegetable has no flavor, in my opinion an
overcooked or overboiled beer wort suffers from the same condition.