July's Cool Fair Maiden: Berliner Weisse

In the swelter of July, as the days stretch long and the nights stay warm and muggy, we reach for replenishers, refreshers, and slakers.  A quintessential summer beverage is lemonade, which our cells recognize as a natural source of electrolytes.  A touch sweet, tart, and crisp.  It cools, it restores.  There is a beery equivalent no less able to restore on a hot day than a lemonade, but it was once nearly extinct and certainly unknown in the US: Berliner Weisse.

Among all the styles in Germany, it is one of the most celebrated.  Napoleon likened it to champagne, and writers rhapsodized about its several virtues. One florid example:

"Berlin is the city of all others where the kühle blonde ['cool fair maiden'] is obtained in the greatest perfection, and where bier-stuben offering no other beverage to their frequenters abound. The beer is drunk by preference when it is of a certain age, and in perfection it should be largely impregnated with carbonic acid gas and have acquired a peculiar sharp, dry, and by no means disagreeable flavour." (Henry Vizetelly, Berlin Under the New Empire, 1879)

Over the centuries, there have been many incarnations of this style.  In some accounts it was made with smoked malt, and over the years brewers made it a variety of different ways.  By the 1970s, the beer had become fairly debased and Berliners were adulterating it with sugary syrups.  Here's Michael Jackson describing what he found there in 1977:

"'White' is a particular misnomer for a beer which is usually drunk either red or green. However delightful they may find the beer itself, visitors from other countries are apt to be shocked by these colors, but Germans are frequently surprised at the thought of drinking a Berliner weisse without a schuss (a dash or raspberry juice) or Waldmeister (essence of woodruff)."

Unlike the red and green Berliner weisses, though, the midcentury beer was a more impressive beast--extremely lean of body, hugely effervescent and quite sharp on the tongue.  A weird beer for which the 1970s had no use--but which is exactly the kind of beer in which modern eyes again see a cool, fair maiden.  And so it has been reborn in the US in all its tiny, powerful splendor.

The Nature of the Funk
To the untrained tongue, a Berliner weisse seems all lactobacillus.  That's the bacterium that produces the sharp, slightly citric tartness you find in yogurt (hence the name).  This is what dominates the flavor of a Berliner weisse, and I have always found it to be a pure, clean note that bespoke no other souring microorganisms.   However, I first got wind of another, secret agent when I read a post by Ron Pattinson a few years ago.  When he had a chance to taste very old Berliner weisses, he found he could taste the barnyard, bone-dry brett character in them, too. 

But is brett important to the flavor profile of Berliner weisse?  I turned to Alan Taylor, my go-to source for all things German.  Alan picked up his brewing degree in Berlin and also brewed there before returning to Oregon.  He's currently at Pints, where you can find his own example of a Berliner weisse on tap now.  His answer? Brett is critical to building complexity in the style, but it does so by working with the lactobacillus.  In typical fashion, he sent along an Excel spreadsheet that had a ton of technical information detailing the differences among Berliner weisses made only with lacto, those with both lacto and brett, and those with just brettanomyces.  Alan comments:

"One of the reasons to have Brett in there early is that it helps to amplify the amount of acids and esters produced. Looking at the chart I attached, you will see that Kindl [lacto-only] has a lower pH, but doesn’t have nearly the level of acids in the beer. Brett on its own also doesn’t create the levels of the mixed pitch. [Lactobacillus and brettanomyces] synergistically create a much more complex beer."

He mentioned that, contrary to my experience, a Berliner weisse that uses a mixed pitch produces acetic acid (the type of sour compound you find in vinegar).  "The acetic brings something along the lines of a Rodenbach note to the beer, which I find appealing."  Finally, beers with brett produce more esters:

The ethyl acetate and ethyl lactate levels are significantly higher in the traditional product. Those esters are being created by the interplay of acid production from the bacteria and the Brett. converting those to esters. As you see, Brett. alone can’t create the levels that the [mixed] has.

And indeed, the mixed pitch produces five times the amount of ethyl acetate (the ester that tastes like pear or apple) and 20 times the amount of ethyl lactate (an ester that can taste vinous or like coconut).  In both cases, the esters are just at or slightly below the threshold for flavor, but their presence creates layers of depth.

I recommend heading down to Pints and getting a pour of Alan's Berliner weisse.  He began with a lactic fermentation and then did an alcohol fermentation with ale yeast.  Normally that's when he would have added the brett, but in this case he waited until after primary alcohol fermentation (for logistical reasons not worth mentioning).  Because you're looking only for ester production from the brett, it only takes four weeks to develop.  Those characteristic "brett" flavors would eventually come out--but long after it has served its primary function.  That's why it's difficult to detect it there.  I tried to focus in on the fruity aspects to attune my palate--a process that may take a few more glasses.

How Tart?
Yesterday afternoon I judged homebrew at the Portland U-Brew and Pub and we had a Berliner weisse in the flight.  The question arose: how tart should it be?  I think there is no right answer here, at least by historical standards.  The brewing methods were very different over the decades.  But if we're looking at the pre-debased 20th century examples, I think the answer is: pretty damn tart.  The chart Alan sent along put them at a pH of around 3--roughly the level of orange juice.  Because there is very little sugar in a Berliner weisse, though (unlike orange juice), that tracks as pretty tart.  (Water is 7.)  Sometimes you'll find Berliner weisses that have been made by sour mashing, and to my palate, they just don't have the pop you get with a full lactic fermentation.  After all, this is why Berliners started adding sugar syrups--it was a really tart style.

(As to Berliner weisses in which the zing comes from chemical grade lactic acid added after fermentation?  The less said the better.  At worst, lactic acid has an unnatural chemical flavor and at best it's a wholly one-dimensional note.  Because there was no fermentation, the lactic acid lacks those critical esters that give a beer depth.  You don't have to be a trained taster to detect pure lactic acid either.)