Rolling boil or vigorous boil?

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
RfN.gif
 
As @hoppyscotty says the difference is latent heat. Basically you are spending energy to achieve a higher boil off.
Your recipe will need to be adjusted for the chosen vigour of your boil, so make notes regarding the boil off volume for next time!
Not to be controversial or a bluff old traditionalist or nuffink, but what happened to the 90 minute boil?
The cost of living crisis, that and having better things to do.
 
I'm a half hour lid ajar kind of person but there must have been a reason why historically people boilled the hell out of beer. Does modern malt need less boiling or what's going on ... coal doesn't grow on trees...
 
Does modern malt need less boiling or what's going on ... coal doesn't grow on trees...
Precisely this (though I've never been able to find out what (ie,  when) "modern" malt is)

Malt contains a chemical called SMM. When the wort is heated, this is converted DMS, which has the flavour of boiled cabbage. Boiling the wort boils/evaporates off this DMS. Modern malt has less SMM than historically produced malt, so needs less boiling to remove the DMS.

There are probably other reasons too.
 
But seriously, Charlie Bamforth is the authority on exactly this question, and is a massive advocate of the vigorous boil. So a long vigorous boil is the technically correct thing to do, but since DMS is seldom a modern problem one can choose to make shortcuts with relative safety.

No boil is a different question though. SMM to DMS conversion starts being a problem from 80°C plus, which is kind of where you need to get to to kill off microbes, so pick your poison.
 
Precisely this (though I've never been able to find out what (ie,  when) "modern" malt is)

Malt contains a chemical called SMM. When the wort is heated, this is converted DMS, which has the flavour of boiled cabbage. Boiling the wort boils/evaporates off this DMS. Modern malt has less SMM than historically produced malt, so needs less boiling to remove the DMS.

There are probably other reasons too.
How can you make those assertions, if you can't even define what modern malt is? 🤔

It's this cut and paste, unverified nonsense that causes most arguments.
 
Interestingly, the "London and country brewer" 1736 discusses this and goes for 60 minutes for pale ales and 90 minutes for strong dark ales. He condemns long boils of several hours.
 
Back
Top