Sour Power: All About Sour Beer

By: Adam Thomas

I’m Adam Thomas, Director of Barrel Operations at MobCraft Beer and have been professionally producing beer for ten years. I started my beer adventure homebrewing in 2011 but soon found a job washing kegs for a brewery out west called Tahoe Mountain Brewing Co. They specialized in oak fermentation and aging mixed culture and sour beers. Over the course of three years, I moved up to head brewer before moving to Milwaukee to help MobCraft brew as well as establish their Wild and Sour Program. 

What Is Sour Beer?

Traditionally, a sour can be described as light, crisp, acidic, and of course, sour. Fruit can be added to balance out the acidity (like strawberry, raspberry, or even peach) and can range in color to bright and vibrant or your more “traditional” beer color. 

Average Alcohol Content Of Sour Beer

This all depends on the style and can range from very low ABV to imperial status. For example, MobCraft makes sour beers that are 4.5, 6.2, 7.1, and 10% ABV.

What Does Sour Beer Taste Like?

What Makes It Taste Sour?

Again it will depend on the style and how you’re producing the beer. Typical American-style sours focus on lactic acid-producing bacteria. Many breweries these days tend to kettle sour their beers to achieve a specific acid level before pasteurizing it and fermenting it with their house strain. Breweries typically do this for two reasons: 

1. They don't have the capacity for a dedicated sour space and don't want to infect their brewery.
2. They’re much quicker to produce than the traditional method, which can take many months if not years.

Traditionally made sour beers still depend on acidity for that “sour” taste, but can be achieved with many more acid producers and a mixed culture fermentation which, in my opinion, creates more complexity and adds depth to a sour beer.

How Is Sour Beer Made?

Ingredients

You’ll use the same ingredients you would on a “clean” beer. Barley, hops, water, yeast (and bacteria). It all depends on the style and what you're trying to accomplish, flavor-wise, in your finished product.

Process

There are many different ways to make a sour beer. Like I mentioned above, the kettle sour method has come into popularity in the last ten years, but traditional methods require some extra steps. The wort is produced the same as any clean beer with a few exceptions for certain styles. 

Keep in mind that most lactic-producing bacteria are sensitive to hops.  More hops = less acid. We use aged hops in many of our sour beers with different dosing rates depending on the flavor we’re trying to achieve. Once your wort is produced there are a few options to take.  Here are a few that we use at MobCraft.

• Primary fermentation is done in a stainless conical fermenter with our clean house strain. Once primary fermentation is complete it gets blended into our sour blending tank which already contains lactic bacteria and a portion of mature sour beer. You can think of this as a starter like you would use in kombucha production.
• Primary fermentation is done in a stainless conical fermenter with our clean house strain. You can then transfer your beer into oak barrels of your choice (bourbon, wine, maple, cognac, neutral) - there are a lot of options!  We then pitch our mixed culture and let the beer age until it reaches the flavor profile we’re looking for.
• Primary fermentation is done in a stainless conical fermenter with a mixed culture fermentation. Typically for these fermentations, we’re not necessarily trying to create a sour beer and rely heavily on wild strains like brettanomyces to create a complex beer in a relatively short time period.

Can I Make My Own Sour Beer At Home?

Yes! These days homebrewers have a wide variety of yeast suppliers that pre-blend mixed cultures and souring bacteria. Try pitching some to a saison or lager recipe you’ve brewed before and see what happens.

FAQs

What foods go well with sour beer?

Spicy foods or foods that are rich in flavor. 

What glass should I use with sour beer?

A Tulip Glass is the traditional glassware for sour/wild ales.

How do I store my sour beer?

In general, sour beers should be stored in a cool, dark space. Refrigeration is often the method of choice. 

What’s the difference between a sour and an IPA?

Sour beer uses yeast with the bacteria, Lactobacillus, whereas an IPA does not have that particular strain of yeast.  

Spike + MobCraft Brew Day 

Adam Thomas is the Director of Barrel Operations at MobCraft. He has eight years of wild/sour production with 3 Great American Beer Festival medals and a Festival of Wood and Barrel-Aged Beer Gold.

About MobCraft Beer

was founded in 2013 by Henry Schwartz and Andrew Gierczak. It is the world’s first crowdsourced brewery. MobCraft’s locations are 505 S. 5th Street in the Walker’s Point neighborhood of Milwaukee, WI and