Tart Sour Beer 2014 • Craft Beer Restaurant


The versatile tart/sour beer category comes of age                           by Charles Bockway

In 2014, no moderately large beer list (15 or more bottle selections) is complete without at least a beer or two in the tart/sour category. While this may have been difficult to achieve as recently as five years ago, it is much easier now as local and regional breweries continue to develop interesting offerings in this category.

Whether its a lemony, refreshing Berliner Weisse or a dark, mysterious wild brown ale barrel-aged on cherries, the sour category is exploding. Consider rotating a sour beer or two through your menu on a seasonal basis, offering the lighter ones in summer and serving bolder ones in winter.

Restaurant Use

Serving Suggestions


  1. tall fluted pilsner or goblet for Berliner Weisse and Gose;

  2. beer tulip for more flavorful and barrel-aged sour ales


  1. colder for Berliner Weisse and Gose;

  2. warmer for darker, more flavorful sour ales

When you talk about sour beers, the taste range is wide. Some are quite sour and some are just pleasantly tart. Some are light while others are very strongly flavored. That is why it is so important to taste these beers before adding one to your restaurant’s offerings. As a whole, they are driven by acidity, fruitiness and malt rather than by bitterness and hop flavors.

Just as a squeeze of lemon or lime brightens the flavor of fruits, vegetables, meats and seafoods, a glass of Berliner Weisse can do wonders when paired with the appropriate dish. A big fruit-laden, dark sour ale can likewise do wonders paired with a range of rich stews, sauces, or intense desserts.

Tech Talk

The sour or tart flavor component comes from natural acid that is produced by a bacterial fermentation of the beer or of some of its ingredients. The most common acids in sour beer are: lactic acid produced by lactobacillus and pediococcus, and acetic acid produced by acetobacter.

Lactobacillus produces lactic acid through the fermentation of sugars. Acetobacter produces acetic acid by digesting alcohol. These bacteria are present in nature and are generally benign. They are both common in other food. For lactic acid, think of yogurt, sour cream, cheese, buttermilk, and sauerkraut. For acetic acid think of common table vinegar such as those made from apple cider or wine.

Characteristics of Tart/Sour Beer

  1. Sourness: mildly tart to sharply sour

  2. Alcohol content: low to moderate

  3. Bitterness: low

  4. Hop Flavor: low

Lactic acid is the dominant acid in most tart or sour beers. Lactic acid also flavors the sour mash used in making Bourbon. Less common, acetic acid appears in small amounts in some sour beer styles, for example, Flanders Red Ale and certain other barrel-aged brews—normally in combination with lactic.

As a flavor component, lactic acid and acetic acid are different. While they both add a degree of sharpness to aroma and taste, lactic acid adds a fruitiness, while acetic acid adds a distinct vinegary taste sometimes described as olives or pickles.

What acidity does for beer

Acidity in beer provides an additional structural flavor element or it may stand on its own as the signature flavor of a beer. In its more subtle application, acidity adds complexity, balance, and freshness. It enhances or balances other flavor components. As in wine, acidity it keeps fruity flavors from being flabby. It adds the extra refreshing quality to Berliner Weisse and Göse that make them such great hot weather beers. In its more assertive applications acidity becomes the dominant flavor to be savored and appreciated, as in Gueuze, for example.

Acidity is not generally a noticeable flavor component of most popular modern beer styles. While some acidity may be present, you won’t really notice acidity in your IPAs, Lagers, Abbey Ales, Hefeweizens, Ambers, or Browns. They rely on other flavor elements to produce balance and interest. One not-thought-of-as-sour beer in which most people can pick up some acidity is Guinness Stout.


Beer historians speculate that many years ago most beer was sour beer because brewers did not understand how to control the growth of naturally occurring bacteria. As the brewing art developed, brewers learned techniques to produce beers that were not soured. In modern beer history, sour beers fell seriously out of favor, and by the mid-to-late 20th century only a few sour styles even remained in production. Lambics and Berliner Weisse were the two best known, but even those were becoming quite rare. It took a new millennium and the experimental American craft beer movement to take hold before brewers resurrected or created new sour beers that have now become all the rage.

More and more today you will find beers to which the craft brewer has purposely added a tart edge. While we are still in the experimental stages here, craft brewers are learning when, where, and how much acidity to add to a beer to produce fantastic new, never-before-experienced beer tastes. The possibilities are exciting and endless. Acidity has definitely become a wonderful tool in the brewers tool box.

Wild or Controlled Fermentation

Like all brewing techniques, the making of sour beer is a blend of old and new, of nature and science. Tart/sour beer is generally produced using one of two methods: wild fermentation or controlled inoculation.

Wild Fermentation

Historically, brewers left the mashed grains or the brewed wort exposed to the open air for a period of hours and allowed naturally present organisms to ferment and sour the beer. Today, many sour beers are still produced wholly or partially by this method, most notable among them may be the Belgian Lambic ales used to make Gueuze. This traditional method harkens back to the days before brewers knew what bacteria and yeast were. That is why it is called wild fermentation. It takes whatever nature offers and uses it to ferment and sour the beer. If a lactobacillus took hold of the beer, it would be soured. Many modern craft brewers of sour beer have adopted the old wild fermentation methods. They feel it gives their beer a sense of place or terrior.

Controlled Inoculation

As modern science developed, brewers gained a greater understanding of the roles of individual yeast and bacteria organisms. They learned to distinguish between the favorable and unfavorable ones. They learned how to control bacteria and yeast through sanitation and brewing processes and learned which organisms actually soured the beer. While many strains of bacteria are present in nature, brewers and scientists isolated a few that produce a pleasant sourness or tartness without adding undesirable aromas or tastes to the finished beer. These specific strains of bacteria are now commercially produced and available to brewers as brewing ingredients, as are acidified malts, which is brewer's malt to which a small amount of lactic acid has been added.

As opposed to an open wild fermentation process, a brewer uses a portion of commercial acidified malt or purposely inoculates a batch of brewed wort with a specific lactobacillus or other bacteria in a controlled, sanitary environment. This way, the brewer has much greater control over the resulting beer sourness and consistency from batch to batch.


Is it a Sour?

Some style descriptors to look for

  1. Wild Ale

  2. Open Fermentation

  3. Rustic style

  4. Barrel-aged

  5. Flanders style

  6. Berliner Weisse

  7. Göse

  8. Gueuze

  9. Lambic

  10. Kriek

  11. Framboise

  12. Old Ale

As always, check with your local breweries and distributors first to see what tart/sour beers may be available in your part of the country. Sours are often seasonal or special releases. Some are on tight allocation due to their limited production runs. Advance planning and ordering ahead may be necessary to obtain some of the better ones.  Following are some tart/sour categories with a few commercial examples of each.

Soured darker ales: Jester King Funk Metal, Russian River Consecration or Supplication, New Belgium La Folie, Lost Abbey Cuvee de Tomme, Deshutes Dissident, The Bruery Oude Tart or Tart of Darkness, Jester King RU55, Upland Sour Reserve, Cascade Sang Noir, Rodenbach Grand Cru, Goose Island Juliet, Duchesse De Bourgogne,

Fruit emphasis:  Belgian-style Kriek or Framboise, Russian River Supplication, Cascade Apricot Sour, The Lost Abbey Framboise de Amorosa,

Lighter styles (Berliner Weisse and Göse) — Bell’s Oarsman, Westbrook Göse, The Bruery Hottenroth, Russian River Temptation, Dogfish Head Festina Peche, Jester King Bonnie the Rare, Crooked Stave Occulus,

Soured blonde or amber ales: Jolly Pumpkin La Roja, The Bruery Sour in the Rye, Crooked Stave Surrette, Wicked Weed Oblivion or Serenity, Cantillion Gueuze, Lindeman’s Cuvee Rene Gueuze, Russian River Beatification, Petrus Aged Pale, Goose Island Lolita.


A sour beer for all seasons