Multiple Beers, One Mash: Parti-gyle Brewing
I've been wanting find as many ways of reusing my spent grain as possible and have been making cookies, bread and even dog treats but I still wanted to get more out my grain. One thing I noticed with the grain is that even after a good sparging there was still some remaining good sugars in mash so I did some research and found parti-gyle brewing. Parti-gyle brewing is the process by which multiple beers are created from one base amount of grains. Often people will make a barleywine then a brown or something similar, going high to average gravity. I decided to give it a try but without following any sort of real formula, just trying to see what kind of beer I could get from a second running. This technique promised a new way to reuse grains and even get more beer out of it! Here's what I did and how it went:
Beer #1: American Brown - OG 1.060 FG 1.009
Beer #2: Small Brown - OG 1.036 FG 1.009
I used an American Brown recipe and drained ~6.25 gal for my first beer, and started that boiling outside in my 7.5 gal keggle. Then I added another 3 gal of water at 155º F and let that sit for about 10 min. I figured the enzymatic activity is pretty much complete, all I wanted was to get any remaining sugars out of there. Those 3 gallons went into my old 16qt brew kettle and we started that on the boil. I had some hops left over from a previous batch and the current one from splitting the 1oz packages so I decided to blend those into the beer. The Brewing Network did an episode on brewing small beers and recommended using a slightly higher hop profile to fill out a small beer and make it taste... bigger. So that's what we're doing here.
I wanted to try reusing yeast that I took from the yeast bed of the last batch of the last Amber I brewed so I decided I might as well try it on this batch. I figure any beer I get from the second runnings is gravy and if my yeast didn't work or was contaminated it wasn't a total loss. The day before brew day I took the collected yeast from the fridge and made a starter with it. I went with 1 quart of water and 3 oz of DME with a 1/4 tsp of yeast nutrient. It didn't take off as quickly as the starter for the main batch which used a fresh smack pack of WYeast 1056 American Ale I, but I did notice slight activity after a few hours which gave me some hope.
At boil the small beer was running a bit low at 1.020 so I added 1 cup DME to bump up the OG a little. I wanted it to be "small" but not too small. Looking back I could add another pound or two of grain to the mash to bump up the second beer a bit. I might add the entire 3 gallons to the sparge, drain into main batch until at appropriate level and then drain the remainder into the second batch. Should be a bit higher that way. The main thing is I don't want to affect the main beer.
Tasting
In the end both beers turned out pretty good but you'd never guess they used the same mash. The main beer is a nice nutty, caramelly brown while the small beer is more of a pale ale or light IPA. I had to wait a while while cooling the main batch, pitching the yeast and cleaning the cooling area before getting to cooling the small batch and this caused the small to boil, with the hops, for an extra 20-30 min or so.
It was only an extra 18 beers or so, but it was a good experiment and proved to me I was able to re-pitch my yeast effectively with no noticeable contamination. I've done this on many other beers since and always gotten good results. A nice benefit is that the small batches give me an outlet for trying new yeast harvesting techniques without being afraid of ruining a full 5 gallon batch. Anyone else tried doing multiple batches with one mash? What was your experience like?
