Thinking Gose...

In these crazy, busy times, I find myself itching to brew another Leipziger Gose. I was incredibly happy with the last Gose we brewed, but things have changed since then. First, I went to Leipzig and tried Döllnitzer Ritterguts Gose. It's awesome, and the sourness is far more assertive than it is with Bayerischer Bahnhof's Gose, so now I'm shooting to emulate Döllnitzer's lactic bite. Second, I've gone all-grain and, as such, am motivated to authentically sour my beer, as opposed to just adding lactic acid to the secondary. The problem? I don't know what they do to authentically sour their beer!

There is very little information on Gose out there. The two recipes I've found (from Randy Mosher's Radical Brewing and BYO magazine) each call for additions of acidulated/sour malt (aka Sauermalz) rather than pitching lactobacillus. I've also seen it suggested that they couldn't have pitched lacto because it would violate the Reinheitsgebot. Of course, the additions of coriander and salt already violate the venerable German purity law. When I emailed the brewer at Bayerischer Bahnhof a few years ago, he mentioned acidulated malt, the addition of lactic acid and the use of a Wyeast lambic blend as various options for souring a Gose, so that didn't really help narrow things down. A German-trained brewer at a Danish brewpub indicated on a German-language brewing message board that Döllnitzer indeed pitches lactobacillus but I can't find his email and am still trying to track him down. And of course there's the option of souring your own mash, but I've heard that's incredibly unpredictable and is too funky for the relatively clean lactic tang you need for a Gose.

I figured it might be worthwhile to turn to Gose's sour cousin, the Berliner Weisse, for advice. Certainly there's more info out there for Berliners, but the more I read various threads about brewing one the more I realized one potential problem: Berliners are incredibly dry and crisp; often the lacto will drop the final gravity to 1.002-1.004. The Goses I'm tasted seemed more in line with a Hefe or Witbier in terms of body. I'm concerned that pitching lacto in the secondary will drop the gravity too low.

After mulling this over, I'm thinking the acid malt may actually be the way to go. Of course the question then becomes: how much acid malt? I decided to look at two Gose recipes and two Berliner Weisse recipes to see what they did. Here's how it breaks down:

BYO's Gose: 11% acidulated malt (1 lb of 9.25 lb. total grain per 5-gallon batch)

Mosher's Gose: 18% (1 lb. of 6.5 lb.)

Weyermann's Berliner Weisse: 8% (they only gave a grain bill in terms of percentages)

Homebrewtalk.com user's Berliner Weisse: 20% (1.5 lb. of 7.5 lb.)

A couple of things to note. First, the brewer at Bayerischer Bahnhof told me the final pH should be between 3.2 and 3.6. Since theirs is less sour than Döllnitzer's, I'm thinking I'd want to shoot for 3.2. However, the Homebrewtalk.com poster indicated that his beer is at 3.9 but tastes tart enough to qualify as a Berliner, so I'm not sure if I should go by pH. Second, the brewer on Homebrewtalk.com said he's getting an apple flavor to the sourness. Not sure what that's about...

So with all this in mind I'm inclined to try the acidulated malt next. However, there are still four questions to be answered:

1.) If I'm using ~15% acid malt that's gonna drop my mash pH and I don't want my efficiency to take too big a hit. Can I/should I do anything about this?

2.) Do I mash hop? Lactobacillus is inhibited by iso-alpha acids from hops, but with the acid malt the lactic acid has already formed on the malt so I don't think it's an issue. That being said, I'm no expert so maybe I'm overlooking something.

3.) Do I boil? I'm still not entirely sure I understand why they don't boil Berliner Weisses, and without that understanding it's hard for me to conclude whether I should be boiling the Gose. I would think I'd need to boil for at least 15 minutes to get the coriander flavor extracted. Of course, if I didn't boil I'd have to mash hop, and maybe I could add the coriander then?

4.) Do I keg condition or just bottle? Like anybody who kegs (and has a four-tap kegerator in the basement) I'd prefer to do the former but many insist on the latter with Berliner Weisses. I've always been skeptical about the differences between keg conditioning and bottle conditioning (isn't a keg just a really big bottle anyway?) so I'm inclined to keg but bottling would make it easier to stash a few away to see how they develop.

So these are all random things that are bouncing around my head as I contemplate my procedure for the next Gose. If anybody has any experience with sours (or, better yet, Gose) and would like to chime in, please do so. And I'll be sure to post what I end up doing so others can learn from my success/mistake/little of both, whatever it turns out to be.