Doing a split batch of beer is a great way to experiment with different ingredients or methods to obtain different flavor profiles or even completely different beers. You can experiment with different yeasts, fermentation temperatures, dry hopping, or other secondary additions. So, don’t be afraid to split a batch because there really aren’t any limits as to what you can do. It can be done with as little as 5 gallons of wort and is as easy as using two or more separate 2 gallon carboys or larger.

If you have listened to any of the recent Come and Brew It Radio podcast episodes there is a good chance that you heard myself or some of the other guys discuss our experiments and brew days, the experiments we tried, our results, and what we learned from those results. This is the information that helps brewers get better.

As an example, when Greg and I brew together, we normally brew two 12 gallons batches. One on his system and one on mine. We split the batch and each take 6 gallons of each wort. Sometimes we will follow the same fermentation processes, but normally there is some difference in how we treat the wort. Once the beers are finished we will reconvene and note the differences between the beers, then bring them to the podcast for discussion with the guys to see what we should or shouldn't improve upon.

You may recall Episode 113 British Golden Ale Experiment #1 and Episode 121 Homebrewcon 2018 Recap And British Golden Ales #2 in which we completed the British Golden Ale experiments. Each time we brewed 24 gallons of wort and used 4 different yeasts. The beers were all fermented for the same time and temperatures, but we ended up with four totally different beers on each of the two batches. By completing these experiments we were able to pinpoint which yeast versions suited the recipe the best for our British Golden Ale kit (not yet on website as of this writing, but hopefully soon!)

Our most common split batch differences are with yeast and fermentation temperatures, such as the recent experiments with Omega Kveik yeasts. We have also used different fruit additions and flavor extracts in certain beer styles. But I also split smaller batches when brewing alone. I have a TBI 15 gallon kettle and brew 9 gallon batches for 8 gallon yields. I brew a 5 gallon control batch and use my 3 gallon keg to do the experimental batch. Another option is splitting the batch at packaging too. Bottle conditioning can result in very different beers when compared to the kegged versions.

Basically, if you are starting a new recipe then it makes sense to split the batch and modify it in different ways to see what you like the best. This can then be the control batch for the next set of experiments as you close in on finalizing the recipe. As with all other experiments, it is best to only change one thing each time so that you will then really notice, appreciate and learn from the differences that the changes in your experiments have made to the beer. And in the end, you have a better recipe

But the most important thing to know about split batches is that it gives you opportunities to learn more about your ingredients, your equipment, your brewing methods, and of course your final product. Enjoy experimenting!!

--Nigel Curtis

Homebrew Consultant, Come and Brew It Radio Host, Cask Beer Lover, Regularly Taunted British Ex-Pat, Thrower of Shoes