Split Batch
By Jeff Lyons
Brewing split batches is a great way to increase your brewing ingredient knowledge in a reduced period of time. By conducting controlled experiments, you can learn about yeast, hops, or even grains at an accelerated rate and allow you to put that knowledge to use in your recipe and process decisions.
While there are many ways to split a batch into two or more variances, the method that I have learned the most from is splitting a batch into two fermentors and pitching two different yeast strains.
I’ve used this method to brew a variety of styles. Sometimes I use two different strains of Saccharomyces, comparing how two Belgian yeasts affect Dark Strongs, Dubbels, Tripels, or Belgian Pales, or how English strains differ with ESBs, Milds, or Browns.
Don’t feel limited to comparing similar strains. Lately, I’ve been using split batches to use one Saccharomyces strain and one 100% Brettanomyces fermentation. I have enjoyed the results of this method applied to an English Brown, a Rye Saison, and I just split a Bier de Garde using Kolsch yeast in one fermentor and Brett Saison yeast in another. By employing a sour mash or kettle sour prior to splitting for fermentation, this method can be taken to another level. The only real limit is your imagination.
I would be remiss if I didn’t touch on a few other ways to split a batch for variety and learning’s sake. One quick and easy way to end up with two different beers from one batch is to mash, boil, and ferment a single batch, then split the batch into two smaller fermentors with different dry hops. This will change the aroma and flavor of the original beer into two distinct beers.
More involved experiments include separate boils to try different hops in the same wort. I recently utilized this method to try out the Hallertau Blanc hop. I wanted to compare the relatively new hop with traditional Hallertau, so I used one mash, split the wort into two kettles, and ran simultaneous boils. Being able to taste the results in the same sitting really helped me to focus on the similarities and the differences that the different hops created.
Fermenting with the same yeast strain but at different temperatures can be a great way to learn how a particular yeast will react to different environments. This can be done at temperatures that are very close to one another to hone in on a recipe and slight variation of yeast character. Alternatively, this can be done at the extreme ends of the temperature range for a given yeast to contrast a very clean fermentation with a more estery flavor profile.
Parti-gyle is another method of achieving two different beers from the same wort, typically one larger beer and one smaller beer. While this will require a second boil, it will produce two very different beers using only one mash. Examples include a Scottish Wee Heavy and a 60 Schilling or a Belgian Tripel and a Patersbier. Another way to conduct a parti-gyle is to make a stronger beer with the first runnings, then add some specialty grains to change the color and flavor to make a vastly different beer with the second runnings. I’ve done this making a Wheatwine or Pale Barleywine with the first runnings and a Red Saison with the second runnings.
Have you tried any of these methods? What did you learn? Do you have a split batch method of your own? What were your most successful trials? Keep experimenting, keep learning, and keep passing what you learn on to your fellow brewers!