The boil

[rpt]

I thought the boil was supposed to be 90 minutes of a rolling boil but I've seen some owners of Buffalo boilers say they only do a vigorous boil for the first and last 15 minutes, and just simmer with the lid on for the middle 60 minutes. I think this was to prevent excessive evaporation. Why would this be any different for the Buffalo and is it a good idea?

 

[Dave1970]

I use a Buffalo and boil on full power for the whole 90 mins.My understanding is that it's not only temperature that's important, the physical movement of a full rolling boil is needed to get the proteins to clump so they don't end up in your finished beer- no doubt someone will be along in a bit who can explain better than me

 

[PD]

a 60 min boil is sufficient....and it saves on electricity and evaporation rates.

 

[jonnymorris]

...and just simmer with the lid on for the middle 60 minutes.

Rather than type out my own recollection of why this isn't a good idea I thought I'd just lift it from his web site...

Once you achieve a boil, only partially cover the pot, if at all. Why? Because in wort there are sulfur compounds that evolve and boil off. If they aren't removed during the boil, the can form dimethyl sulfide which contributes a cooked cabbage or corn-like flavor to the beer. If the cover is left on the pot, or left on such that the condensate from the lid can drip back in, then these flavors will have a much greater chance of showing up in the finished beer.

 

[rpt]

OK, you've confirmed what I thought. Thank you.

If only boiling for 60 minutes do you need to increase the hops?

 

[PD]

I do.
I alter the recipe in brew mate to a 60 min boil, and increase the hops slightly to keep the end bittering value roughly the same.

 

[theboytony]

There is some good info in this thread about boil times

http://www.thehomebrewforum.co.uk/viewtopic.php?f=36&t=29154