Since I started brewing, I’ve always been ready to use one of the best tools in a brewer’s toolbox, brewing a large enough batch to split and get two or more different beers. Not only do I learn something about the recipe, I get double the amount of beer for the effort of brewing a single batch. You just have to keep one thing in mind: focus on making a recipe that captures what you want in the first beer first.
The Primary Beer
Basically, you want to determine what you want most from the batch and build the recipe around that. If you are staying true to style, be sure the recipe hits up all the characteristics of a classic BJCP style as far as malt and hops go, then choose the best yeast. There are now more manufacturers of both liquid and dry yeast than homebrewers have ever had access to, so your options are vastly improved compared to even a decade ago. You can easily do a little research on that bitter or ESB and get an actual Fuller’s strain or that NEIPA and get a Conan-derived strain. Just do everything you can with the recipe and process to get exactly what you want out of half the batch. Why? Because if something doesn't go well in the second half, you still win.
Once you have the first half of the recipe set, get into the fun stuff and start tweaking it. This is where you can do a variety of different yeasts, dry hopping, or secondary additions to make a totally different beer from the same exact recipe.
The Full Variety
I’ve learned and helped other learn the variety of differences yeast alone can make on a beer by taking a 5 gallon batch and splitting it into five 1 gallon batches to try numerous options of both liquid, dry, ale, and lager yeasts. You’d be surprised how much a standard pale ale can change when you branch out from a regular Cal Ale and use an off-shoot like American Ale II or any English ale yeast. And then there’s Belgian, which takes it into a whole other territory of flavor. All while helping you learn more about the ingredients in your recipe. Your packaged quantity will be more limited here, but if you kept with best practices for fermentation you should get good results. And for packaging, you’ll most likely need to go with bottle conditioning. More of us have multiple 5 gallon kegs than we do smaller kegs.
The Two Way
The easier and less involved version of making a split batch is to aim that batch at being split a certain way. I’ve done this most often with IPAs. First choice to change is usually yeast and I’ve done multiple versions of West Coast style IPAs using a Belgian Ale yeast or Cal Ale/Belgian Saison blend on the second half to get a Belgian IPA with varying Belgian ester character. It’s amazing how different the flavors can be in the same recipe with this approach. But you don’t have to go that far out of bounds because you could simply change the type or amount of dry hops and see a large difference between your two beers. Or even the temperature of fermentation. And if you started off by aiming for lower bitterness in a West Coast, you could easily choose a yeast like Omega DIPA and then vary the dry hopping amount and timing to end up with a clear and crisp West Coast IPA and hazy NEIPA. Using this same logic, an American Pale Ale can gain a large ester profile from English yeast or a lighter RIS could become a Tropical Stout with a larger ester profile and more smoothness.
The Secondary Additions
The simplest approach to getting two different beers from the same recipe is to make additions in a secondary. This is where you can find out what wood aging and liquor flavors can do to almost any style or how much coffee or cacao nibs and roasted coconut and almonds might change a sweet stout. Better yet, it’s where you can find out how much fruit additions modify a beer’s flavor and body due to secondary fermentation. And of course, i won’t leave out simple sugar additions and natural or artificial flavorings. The latter I’d say leave for the kegged beer so you can dial it in per pint, but the former can give you a lot of flavor variation depending on what sugar you choose. Rum soaked oak aged imperial brown ale with multiple demerara sugar additions? “Yes, more please!” said most everyone who tasted it.
Experiment. Enhance. Improve.
What I hope you can take away from this is that the key thing is to work a little harder for a larger reward. Be willing to make that extra wort to experiment with or to make 10 gallons of the exact same beer, but enhance it in some way to create something new. Because either way, no matter how you do it, if you are trying new things you are learning something about the process that’s making you a better brewer. You will have improved your brewing knowledge.
Semi-Media Director/Special Event Coordinator TBI, Producer, Writer, Host, and Host Wrangler Come and Brew It Radio, Homebrew Consultant, Lover of Experiments