Boil length impact xbmt

[Rick_UK]

Good discussion guys. Just for the record I'm not saying this one 'experiment' disproves conventional brewing wisdom but it does reinforce the value of experimentation and creative thinking. I'm not convinced commercial brewing processes should be replicated by the home brewer verbatim as they are based on the lowest commercial risk and a need for absolute consistency. As Nick hypothesises the chemical reactions achieved in the boil may not follow the same patterns when scaled down to a typical home brewing set up, and then there is the limits/subjectivity of human taste perception which may well be unable to perceive what, at a microbiological level, are significant differences. Being able to measure scientifically all the ins and outs of brewing is great but if the beer doesn't taste any better then is it really necessary...

[simon12]

I am sure you guys know alot more than be about this but even if a 30 min boil is as good as a 60 or 90min boil (I am not saying it is or isn't) would it not still make more sense commercially to do 60+ mins as the extra bittering hops would cost more than the extra energy.

[Cheesey]

Interesting stuff for a newbie trying to hone my process.

One thing I've been doing. I use Brewsmith software which has built in evaporation rates. It defaults to a 90 min boil and has target post boil volume.

However the software doesn't know that I have two elements, an insulated boiler nor the atmospheric conditions. What I aim for is the pre boil volume and target post boil volume (ca. 10.6% reduction). This in my set up tends to be around 75 minutes.
This is more of a measure of the intensity and local conditions, the chemical reactions will not just be time dependent, but as thermodynamics are involved must also take in to account the amount of energy, efficiency, and evapouration loss.

Just a thought.

C

[Rick_UK]

Absolutely. Brewing software is a useful tool which provides a good estimate of your efficiency, hop utilisation, evaporation rates etc but you need to know your own equipment to set the parameters for accurate results. Even then, as you say there there is variation in grain/hop properties, atmospheric conditions, water chemistry etc. It's easy to be fooled into thinking that something that involves numbers and calculations produces a definitive factual result, when (quantum physics aside) it does not. Brewing is equal parts art and science - which for me makes it far more fun!