For me, one of the most frustrating aspects to brewing sour beers is the wait time before you get to drink the beer. Even the quickest turn around sours will still take around 3 months to finish (with the exception of sour mashing, but that’s a different story). More often than not, I’m willing to take on a long wait for a big payout. However, there are occasions where my brewing schedule wont allow me to use a brew day making something I wont be able to enjoy for a year or more. On these rare but regretful occasions, I take the middle path and do a split batch.
The concept of split batch brewing is incredibly simple. Take one wort, put it in two different fermenters then BOOM you have a split batch. With this grossly simple overview covered, there are a number of options for you to choose from. The first thing to decide is what sour you want to start out with. From there you can determine what your non-sour beer will become. I’ve outlined a few options for transforming a sour base beer into something unique and exciting.
One idea is to match your sour style with a complementary non-sour style. Many beers in the sour category line up very well with the “standard” beers set forth by the BJCP guidelines. If your making a Lambic or Geuze, you can make the other half of your batch a wiezen. Considering that a large portion of a lambic’s grain bill is wheat malt, and the hopping rate is low, transforming the recipe into wheat beer is an easy shift. I would stick with a classic German krystal or hefeweizen, rather than an American wheat, as these styles most closely match the lambic malt and hop bill. Oud bruin’s vital statistics are almost in lock step with those of a Northern English Brown ale. By using a nice hearty English yeast strain you could easily make this beer into a complex malty version of the classic English staple. Unfortunately, Flemish Red ales do not have a perfect correlate, but they can become the base of a number of excellent beers. You could turn your Flemish Red into a rustic Saison, a Belgian Specialty ale, or even a fruit beer. Other than matching style you can add a number of adjuncts to transform part of your wort into something completely unique.
Apart from matching style, you could also doctor your wort to make something completely new. In an episode of Brewing TV, the guys used Dark Belgian Candy Sugar as one of the sole darkening agents with a very light beer base. Since Belgian candy sugar can be used after the boil, it provides an excellent adjunct in the carboy. Along this line, you can use another sugar to boost up the alcohol of your non sour beer without changing any color. You could use light Belgian candy sugar to transform a lambic into a Belgian golden ale or ample honey to create a braggot. Finally, you can use cold steeping of dark grains to transform a Flanders red or oud bruin into a Belgian stout.
There are a number of other ways to doctor your non-sour beer in order to make it something unique. One excellent way of doing this is by adding Fruit. The choice of what you add is up to your personal preferences and possibly what is growing at the time. I think that exotic fruits and fruit blends are a lot of fun and can give you something rare. If you want to stick with tradition, cherries (for a kriek like beer) or raspberries (for frambois type style) would be the way to go. Very interesting beers can be created by the addition of oak. It can turn a boring and bland beer into a rich blend of vanilla, smoke, and coconut. Finally, if you find that your base beer lacks a any interesting character, you can try dosing it with some tinctures.
One final thing to keep in mind is the how much of an effect temperature has on the fermentation. If you are lucky enough to have multiple areas to ferment, you can pick a specific area for your sour and another for your non-sour beer. If you limited to one area to ferment, you have to decide what temperature to keep your beers at. Most sours ferment best and fastest in a slightly warmer environment. That being said, they will ferment at lower temperatures but it may be sluggish. Now, it is possible to ferment your non-sour beer at higher temperatures and have the best of both worlds. Strains that work very well at higher temperatures include wheat beers, Belgian strains, and saisons.
Recipe: Funk and Fruit Split Batch
Doing a split batch gives you one beer that you can drink in a short amount of time and another that you can savor in a year or two. The fruit beer provides an intense bouquet of tropical fruit and a slightly sour undertone. The flavors of the fruit evolve over time, giving you a new beer every few months. The sour beer is a basic Flanders Red, with a nice solid amount of funkiness and a pleasantly subtle sourness that makes this an incredibly easy drinker.
Malt and Hops: 8 Gallons
- 7 lb Pilsner Malt
- 7 lb Vienna Malt
- 10.5 oz Aromatic
- 10.5 oz Cara Munich
- 10.5 oz Special B
- 10.5 oz Wheat Malt
- 1.33 Lb Munich Malt
- 1 oz Hallertau – 90 min
Notes: The fruit beer component was racked onto 6 lb of Mango/Strawberry/Pineapple/Peach Mix from Costco after the primary fermentation was complete. The Fruit beer was then racked to tertiary to age. The sour beer was fermented in primary for two months then aged in a 6 gallon carboy for another ten months. After a year the beer was kegged and put on the infamous golden sour tap.