Forget hops…over the past several months, I’ve been slowly becoming what can be called a sour head.

After having a few phenomenal sours at GABF, and more recently sampling stuff like Russian River Consecration and Supplication at a friend’s beer tasting event, I’ve been itching to brew my own. I did some research into styles, bacteria and brewing processes, and decided to focus my first foray into the category on making a Berliner Weisse, a very delicate, low-alcohol beer that originated in northern Germany several hundred years ago.

When Napoleon’s troops marched into Germany and sampled the beer, they called it “the champagne of the North,” and it does indeed resemble a champagne with its high effervescence and dry acidity. They generally come in between 2-3% ABV, with extremely little (or no) hop bitterness or aroma, and are often served with various syrups to balance the trademark sourness. The grain bill is very simple, traditionally made up primarily of pilsner malt with about a third (sometimes up to half) wheat. The puckering sour in the beer comes from lactobacillus delbrueckii, a bacteria that can be imparted in the wort any number of ways, either naturally using a sour mash or via inoculation from a prepared culture as I did, figuring the sour mash procedure seemed like too much of a crapshoot on the level of sourness you’d ultimately get.

It’s fairly difficult to find commercial examples here in the Twin Cities. But if you’re willing to order beer online or travel to Hudson, you can find a few nice ones (often seasonal) including The Bruery’s Hottenroth, New Glarus’ Unplugged Berliner Weisse, and Dogfish Head’s Festina Peche.

Here’s the recipe I went with for a five gallon batch:    

3 lb Pilsner
3 lb White Wheat
1 lb Carapils
1 oz Tettnanger (4.4%)
Wyeast 5335 Lactobacillus Delbrueckii
Wyeast 1338 European Ale

Saccharification rest: 152 degrees for 60 minutes
Sparge: 170 degrees for 45 minutes
OG: 1.028

This is a no boil recipe…yes, you heard me right…no boil. And the reasoning behind it is two-fold. First, while I decided to inoculate the wort using a bacteria culture from Wyeast, I figured it wouldn’t hurt to let any naturally occuring lactobacillus from the grain husks in the mash play a less significant role in upping the sourness of the beer (assuming any survived the saccharification rest). I suppose that also means there’s potential for other unwanted bugs to get in the beer, but I’ll take that chance (the style is also known to have low levels of brettanomyces, which isn’t necessarily a bad thing). Secondly, hops play an extremely small, almost non-existent role in this type of beer, so I hopped in the mash using a small amount of the low alpha acid German Tettnanger as opposed to boiling which would have extracted and utilized more compounds than required. Hop compounds can also inhibit the growth of bacteria (ever heard that hops have a preservative effect?) which is counterproductive for this style.

Once I had collected my wort, I cooled down to about 85 degrees and pitched the bacteria into the carboy, thinking that the bacteria would work more effectively at a warmer temperature as opposed to cooling to the preferable 65-68 degree range for ale yeast. I gave the bacteria a 24 hour head start before I pitched the yeast, as I wanted the bacteria to get some sugars before the yeast came into the picture and gobbled everything up. However, the bacteria can quickly cause the pH level in the wort to become too acidic, creating an unsuitable environment for the yeast to do its thing. So 24 hours seemed like an appropriate timeframe between bacteria and yeast.

Within 12 hours of pitching the yeast, I saw a small but active krausen in the carboy. The beer’s original gravity is only 1.028, so very small. I’m anticipating this will finish out around the 1.002 range, giving me about 2.5% ABV. After primary fermentation and a diacetyl rest, I’ll condition in secondary for a few more days before I bottle. When I do package the beer, I’ll dose it with another shot of lactobacillus and let it bottle-condition for at least a couple months.