Parti-gyle Math or Diluting Big Wort to Brew Smaller Beers

[Jason Garland]

As an interesting topic for the club educator: how about walking us through parti-gyle math?

Here is the scenario:

Rob Eger, John Krupka, and me are contemplating a big mash of Vienna lager on my 15 gallon keggle mash tun. I have not tried brewing that much wort on this system and Rob suggested we make a strong wort, then dilute it to get three shares' worth of wort out of it. I remember reading about parti-gyle brewing a while back and the article explained how the brewers mathematically calculate how to blend runnings in order to end up with X volume of wort at a specific gravity. That sounds applicable to this application but since I never could get my mind around the math involved, it was suggested this might be a good education topic.

So...care to take a stab at it? (Or anyone else for that matter?)

[James Smith]

Try this at your own risk: https://www.astrocaver.com/java/Parti-Gyle.html. However, it was recommended on some forums.

Here's the logic of the method explained: https://beersmith.com/blog/2011/10/07/p ... -one-mash/