“Do you like sour beer?”
“No. Sour. Ick.”
“Do you like lemonade?”
“Yeah! I love lemonade!”
“Then you’ll probably like this sour beer.”
This is a conversation I’ve had more than once since I started brewing. For quasi-understandable reasons, lots of people react poorly to the term “sour.” To win over converts, we brewers have at our disposable a light, grainy, zippy and citrusy (depending on how you make it) beer known as Berliner Weisse. It’s an incredible “gateway” sour beer—approachable and fresh and light. And the good news is that brewing one is (or can be) easy! While more-complex sours can take months or even years to fully develop, the slap-you-in-the-face, clean lactic acidity of Berliner Weisse can be accomplished in just a couple of days—or, if you’re impatient, even a few seconds.
The beer that Napoleon referred to as the “Champagne of the North,” Berliner Weisse is a very light (in color and alcohol) wheat ale that features a bright and prominent acid flavor that is back-stopped by a touch of wheaty/grainy malt and very low bitterness. The champagne comparison is definitely valid, as the style finishes quite dry and definitely spritzy—carbonation tends to be very high. Some examples (including this one) can feature some fruity flavor, and strictly speaking it should feature no hops flavor, but we’re going to confound the style a bit on that score (with good reason, I promise). The result is a thirst-quenching beer that can be consumed in large quantities but is also bursting with character—it’s a fantastic session beer (happy belated Session Beer Day to all!).
The grist is simple: four pounds (1.8 kg) of Pilsner, three pounds (1. kg) of wheat (for a slightly stronger version akin to Weihenstephan 1809, make it four pounds.1.8 kg of wheat). That’s it.
Hops? Sure, why not. Conventional wisdom says to keep the hops at bay in this style, but I personally find that to be highly uncreative. It’s true that this isn’t a conventionally “hoppy” style, but that doesn’t mean that the right hops can’t complement our flavors in a way that makes the beer pop! I like a split-hops addition here: half an ounce (14 g) of Hallertau (unsurprisingly) but also half an ounce (14 g) of Sorachi Ace. Why a Japanese hops variety in a North German beer? Simple: because it has just the flavors we want. Sorachi Ace has a lemon-lime flavor combined with a grassy/herbal flavor that meshes well with the Hallertau, and the citrus accents the acidity beautifully, giving it an almost lemonade-like flavor. “Okay, but what about some of the New Zealand varieties? They’re lemon-lime heavy, too!” True, they are, and you can certainly give them a shot, but I’m guessing that you’ll reach the same conclusion I did when I tasted them in this style: too much. The New Zealand hops that I’ve had in Berliner Weisse all make the beer seem like a sour session IPA instead of a sour wheat ale.
You’ll also need some yeast and a Lactobacillus culture. In the interest of simplicity, I stick to my Wyeast 1007 (German Ale) yeast—it’s traditionally appropriate and a pretty clean yeast that adds a touch of esters. It will get the job done and won’t get in the way, but it still adds some flavor. And while there are lots of ways to get Lacto into your beer (dregs, grain additions in the fermentor, etc.), for such a spare and clean beer, this is really a case for a pure culture (I tend to advocate that anyway, but especially for Berliner Weisse).
This is where things get…tricky. There are a wide variety of ways these days that homebrewers have to sour a beer. I’m going to give you three options here that I can recommend, simply because I’ve done them and had good results. One important note, regardless of souring method, though: boil for only 15 minutes, and add all of your hops at the start of the boil!
Kettle souring is a pretty straightforward process (but please look up the details—this is just a quick sketch). It involves a mash, lauter, sparge, and then flushing the kettle head space with CO2 and spiking the wort with your Lactobacillus culture while holding at a specific temperature. After a couple of days, you come back and boil as usual. This lets you dial in a very specific level of sourness (because it’s to taste) and has the added benefit of killing off all of the bugs which ensures that they don’t end up in your equipment! Dead bugs contaminate no wort. Post-boil, just ferment as usual with your yeast (after a possible pH adjustment).
Pitch and Wait
In this method, you mash and boil and chill as usual, then add your Lacto culture to the fermentor. After waiting a reasonable interval (at least a week; I prefer two) to give the bugs a head start, pitch your yeast. If you add the yeast too soon, it will outperform your bugs and you might end up with very little acidity! If taking this route, be sure to clean and sanitize rigorously any plastics that come into contact with the wort (I keep a dedicated set of “sour plastics”).
Either as a primary source of lactic acid or as a way to bump up acidity that didn’t form upstream, you can take the cheap and easy way out: spike your beer with lactic acid. It works. Ignore people who say it “can’t work” because it’ll taste too artificial. I used it in one of my earlier versions of this recipe, and it won Best of Show at a regional competition. If the other methods intimidate you, consider this as an alternative! It’s inexpensive, and you can add it (again, to taste) directly to the finished beer at packaging.
Speaking of packaging, that’s our last step: carbonate this beer to a full three volumes of CO2. Your bottles can handle it (if you’re bottle conditioning), and you’ll love the way it brightens the flavor and fills out the mouthfeel!
Sour beers can be intimidating to even experienced brewers, but this style is a great way to start learning the process and enjoying homebrewed sours! It also puts another option in your “session beer” quiver. One last note: you can also hit this beer with Raspberry or Woodruff syrup at service, and their red and green jewel tones make Berliner Weisse a fun Christmas Party choice!
From Berliner Weisse to Gose and points in between, quick souring is rapidly becoming the time-constrained brewer’s choice for building pleasant tartness on a schedule. In Craft Beer & Brewing Magazine®’s online course, Quick Souring Methods, Funkwerks Cofounder Gordon Schuck explains how to use Lactobacillus bacteria, experiment with sour mashing, test acidity levels, and more. Sign up today!