We’d been playing with the idea of a parti-gyle brew for a while. This is where you take the first lot of sugary liquid from the mashed grain to make a strong beer. You then run more water over it to flush out any remaining sugar and that second, less-sugary liquid is used to make a weaker beer. Here’s an old article by Randy Mosher on how to do it.
When I hit upon the idea of brewing Bailey a surprise birthday beer, I knew I couldn’t brew an entire batch in secret, but I could hide a small carboy of beer. So, part-gyling seemed the natural way forward.
I was definitely impressed by the results, and I think Bailey was too (well, he can’t say he doesn’t like his birthday present, can he?). More excitingly though, it showed us that parti-gyling is pretty straightforward and allows you to experiment a lot more on brew day and make two very different beers with only a little extra effort.
Full details on how I made the beers can be found after the jump.