What Is a Sour Beer?

If we had to guess, we’d wager your first sip of beer was when you were underage and resulted in you instantly developing bitter beer face, the famed expression of a person unaccustomed to the taste of alcohol. 

Fast forward (well into legal drinking age, of course), and you’ve developed a palate that not only enjoys the tart, bitter flavors of a good IPA but also the more complex tastes of a sour. 

Sour beer might sound like the sort of thing you should throw away, but it’s actually the foundation of all beers we drink today. Before pasteurization and refrigeration, all beers were sour beers, and for those that love them, you can still find them from craft brewers.

Here’s what you should know about sour beers, including what they are, how they’re made, and what to pair them with. 

What Is Sour Beer?

Sour beer is precisely what it says it is: beer that is sour in flavor. Sour beers range from tart to downright pungent and earthy, and there’s a wide range of flavors to experience in between.

Sour beer is hard to make; get it wrong, and you’ll end up with flavors that have been affectionately described as dirty diapers, Band-Aids, rotten apples, and wet horse blankets. Get it right, and you’ll get a light beer with a complexity of flavors that pairs perfectly with strong foods or just a Sunday afternoon.

Who Likes Sour Beers?

Sours appeal to beer geeks and beer novices alike. Because sour beer is generally lighter and has a flavor that is so vastly different from an average beer, it’s appealing to non-beer drinkers. 

The multiple layers of flavor and the complexity of the brewing process make them top the extensive lists of some beer aficionados. 

Sours vs. IPAs

“Isn’t it just like an IPA?” It’s a fair question, and we get that a lot. IPAs are known for their bitter finish, and that comes from the addition of specific types of hops (and lots of them). 

The difference is how they’re fermented. With an IPA, the fermentation is highly controlled and sterile. The yeast used is measured, and ferment times depend on the predictability of the yeast in the beer. 

A sour is made with wild yeast, which, like its name suggests, grows wildly, rampantly, and gives the beer a stronger acidity than you’ll experience with an IPA. 

Where Were Sour Beers Born?

Belgium appears to be the country of origin for commercially produced sours. However, as previously mentioned, all beer was sour beer before the invention of pasteurization, which weeded out bacteria and kept beer “fresh.” 

Sours first appeared in the U.S. after the Civil War, when immigrants from Germany and Belgium brought it with them overseas. It was still hard to find until the 1970s, when the craft brewing movement began to gain steam, and home brewers who lacked the tools to pasteurize their beer produced sours that were marketed for their tartness and earthy taste. 

It was a hard sell to the U.S. public at first, with some people returning their beer because it was surely past its date. Once brewers perfected their craft, the public couldn’t get enough sour goodness.

How Is Sour Beer Made?

Sour beer is made by using a mixture of bacteria and yeast. Two different types of bacteria are used in making a sour. 


  1. Lactobacillus. We’re all familiar with this strand of bacteria, which is what gives yogurt its tart taste. Lactobacillus turns sugar into lactic acid, which is why a sour beer differs in flavor from other beers. 
    While most beers have some sweet flavors, a sour retains fruit flavors without sweetness, leaving behind tart flavors only. 
  2. Pediococcus. This bacteria is a cousin of lactobacillus and is often added to the fermentation of a sour beer to increase acidity and produce a rich, buttery flavor. Pediococcus oxidizes continually without oxygen, so the longer the beer ferments, the richer the buttery flavor will be. 


The yeast used to make sour beer is different from standard beer yeast. Brettanomyces is the yeast that separates the men from the boys, or rather, the sour beer from any other you’ll ever taste. 

Brettanomyces, commonly referred to in beer drinking and brewing circles as “brett,” is the bad kid on the street with unrealized star qualities. It can quite literally make or break a sour beer. 

This wild yeast can create a flavor that tastes unmistakably awful or gives a sour a balancing earthy flavor that matches perfectly with the tartness provided by the acidic bacteria. 

Yeast itself is a fundamental ingredient of beer, but the two most commonly used are saccharomyces cerevisiae and saccharomyces pastorianus. These yeasts are referred to as top and bottom yeasts, respectively. 

Top fermenting saccharomyces cerevisiae is added to the wort (the boiling, bubbling vat of grain that eventually becomes beer) at the top, when it’s hottest. Saccharomyces pastorianus is added to the wort at the bottom of the boil when the temperature has cooled. Tops traditionally make ales; bottoms traditionally make lagers. 

Tastes of Sour Beers

There are several different styles of sour beers, most of which are still brewed overseas and imported. However, American wild ales are ever-growing in popularity, and their availability is increasingly more consistent. 


Arguably the OG of sour beers, this Belgian-style beer is made by spontaneous fermentation, a process by which a brewer basically dumps the ingredients in the barrel and lets the organisms on the barrel, in the air, and on anything else ferment in the brew. 

Lambic is light, tart, typically brewed for more than twelve months, and left in the open, cool air during fermentation. 


Flanders are either red or brown. Brown flanders are also referred to as Oud Bruin. 

These Belgian-style ales are richly fruity in flavor, with reds having a vanilla or slightly buttery finish and browns showcasing an earthy flavor similar to kombucha with acidic fruit flavors of plums and grapes. 


Gose is a German-style sour beer that is characteristic because of its salty taste. German gose is traditionally flavored with coriander seed (the seed of the cilantro plant) and salt. 

Gose is light, and many people find it to be an easy sour to drink because of the balancing salt to sour ratio.

American Wild Ale

The American craft brewer’s version of sour beer comes in the form of American wild ale. These brews are made by specialty craft brewers who typically specialize in sours. They’ll generally be made with standard yale east and brett. 

Some of our favorites:

  • The Rare Barrel’s Cosmic Dust is award-winning, aged in oak barrels, and made with pediococcus and brett. This beer has layers of earthy sours, tart berries, and of course, a little brett funkiness to round out the palate. 
  • Lolita. This American twist on Belgian-style pale ale is fermented with raspberries to produce a truly acidic and tart taste that is unmistakably akin to framboise. A beautiful pink color, this is an easy-to-drink sour that is light and refreshing. 

Berliner Weisse

Another German sour is Berliner Weisse. This beer is lower in alcohol content than most beers and has a light, lemony taste that makes it easy to drink. Highly carbonated, it’s incredibly refreshing when served ice cold in the heat of summer. 

Sour Beer Pairings

Sour beer has its place at your table, even if you can’t imagine what to place beside it. Sours are perfect for foods with strong, vibrant tastes, as they balance those flavors and can help cleanse the palate between bites. Need some suggestions:

  • Spicy dishes like hot pad thai, and mild spice like fajitas or tacos
  • Strong, highly aromatic cheese like goat and Limburger
  • Fatty cuts of meat like New York strip and ribeye
  • Sausages and brats
  • Fried foods; the lightness of the sour can balance out the heaviness of fried food

If you already love sour beer, you can probably pair it with practically anything. If this is your first foray into sours, try them alone to fully appreciate the complexity of their flavor. 

Tap Into Better Beer

We know you love beer, and if you aren’t a sour lover yet, you can become one. TapRm makes it easy for you to taste sour beers from all over the country by connecting small breweries to the beer drinkers who love them. 

Our selection of sours is carefully selected from obsessive brewers across the nation, so you can enjoy the flavors of a legitimate sour ale correctly without worrying about a brett yeast mishap. 



A Brief History of Sour Beer | New Yorker 

New yeasts—new brews: modern approaches to brewing yeast design and development | Academic.OUP 

Should Sour Beer Have its Own Category? | Hop Culture

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