Goses are essentially wild ales — they get their most important quality from Lactobacillus — so the decision about how to sour the mash is the first and most important consideration. To make Bahnhof’s gose, Richter begins by cultivating lactic acid in his cellar from the naturally occurring bacteria found on the wheat. (According to Reinheitsgebot, brewers may not add chemical lactic acid. They must create it naturally.) He then blends an acidified wort with a standard wort to achieve a consistent pH level. There are other methods, and we’ll address those in Next Steps.
Oddly enough, Richter ferments his gose with a weizen yeast, but ferments in a cylindro-conical tank to restrain ester and phenol production. He also skips the ferulic acid rest, further limiting the phenolic potential. Richter advises, “If you like to have a noticeable wheat taste, you should use wheat yeast you would normally use for a wheat beer. Otherwise, you can use any neutral top-fermenting yeast; for example, a yeast for a kölsch.”
Seasoning the gose is, far more than spicing a wit, a matter of brewer preference. Richter says with salt, “you’ll have to try for yourself through trial and error” what amount works best. In Brewing with Wheat, Stan Hieronymus quotes Richter as saying he adds 500 grams of table salt to a 15-hectoliter batch — or about 1.25 teaspoons per gallon. Trust Richter on this one, though; salt is such an assertive ingredient that overdoing it could easily ruin a batch of beer.
- 4.25 pounds German pilsner malt (50%)
- 4.25 pounds wheat malt (50%)
See Fermentation and Conditioning below. For an alternate method, see Next Steps.
- 144 to 147°F (64–67°C) for 15 minutes
- 162°F (72°C) for 30 minutes
- 0.5 ounce German Northern Brewer, 60 minutes (8.0% AA, contribution of 14 IBU)
- 0.5 ounce cracked coriander seed, 15 minutes
- 1–1.5 teaspoons table salt at knockout
Fermentation and Conditioning
Ferment at 68°F (20°C) with a 1:1 ratio of Lactobacillus to regular ale yeast. Wyeast 5335/White Labs WLP677 (lacto) with 3056/WLP300 (wheat) or 2565/WLP029 (kölsch).
Bottle-condition or keg.
Expected OG: 10.5° P/1.042
Expected TG: 2° P/1.008
Expected ABV: 4.5%
Expected bitterness: 10–15 IBU
Notes: Matthias Richter has the spirit of a homebrewer, and he encourages everyone to experiment as they go along. Nearly everything can be adjusted to your preferences, from the boil time (up to 90 minutes), hop variety and amount (though hops should be at most a subtle note), and the salt and coriander amounts. One of the biggest decisions is how sour you want your gose to be. To begin with, choose lacto-to-yeast ratios of between 1:3 and 2:1. When pitching yeasts with bacteria, you lose flexibility in adjusting sourness, but it is by far the easiest method.
Gose is a great style of beer to practice souring techniques. You’re working mainly with Lactobacillus, so the different approaches can be compared in a relatively scientific setting (that is, you don’t have to figure out what wild Brettanomyces or other wild microorganisms are contributing). Richter suggests two more methods of souring a gose in addition to pitching mixed cultures: sour mashing and kettle souring. These accomplish the same thing but in slightly different ways. In kettle souring you’re pitching a pure Lactobacillus culture in wort, while in a sour mash you’re encouraging native Lactobacillus on the grain to produce lactic acid.
Sour mashing is an old practice — and in the United States, a backwoods technique used to make whiskey — but it is very risky. As the name suggests, you make a regular mash and then let it sour over the course of hours or days. Wild Lactobacillus on the grain will stir themselves and go through a lactic fermentation, but there are a lot of other wild microorganisms on the grain as well, many of them in the food-spoilage class. Once those fellows get going, your mash may smell any manner of putrid (garbage, rotting vegetables, stinky feet, and so on).
More from The Secrets of Master Brewers
Excerpted from The Secrets of Master Brewers © 2017 by Jeff Alworth. Used with permission from Storey Publishing.