How to Brew Sour Beer

There is nothing new about sour beers except for the unprecedented property they’ve gained lately. Sour beers with their tart and acidic, high notes have become all the rage among people who binge on unique beer variants with complex compositions. The popularity of sour beers has also spilled over to the craft brewery landscape.

People who like to brew their own drinks consider sour beer a challenge in comparison to other beers for one big reason, i.e., its contamination power. Even traces of sour beer in your brewing setup can mess up with your clean batch of light beers such as pilsners and pale lagers.

If you want to take on the challenge of brewing sour beer in your craft brewery setup while making sure no contamination of clean batches happens, continue reading this article. Here, we’re going to discuss how to brew sour beer at home for its right characteristics and without stressing over its contamination consequences.

First, we’ll discuss all the equipment and ingredients you need and the steps you’ve to follow for brewing sour beer. Next, we’ll look at ways through which you can carry out this brewing in a controlled environment to ensure no exposure and contamination happens in the later beer batches.

A close-up of a glass filled with foamy sour beer

What You’ll Need to Brew Sour Beer

  • A boiling pot (around 8L in volume for a 4.5L batch)
  • Non-rinse sanitizer
  • Kitchen scales
  • Thermometer
  • Funnel/ bottling wand
  • Fermenter and airlock
  • Empty bottles and caps
  • Strainer

Pick Your Ingredients

Picking the right ingredients is half the work in brewing a perfect batch of sour beer. Here, we’re going to share all the ingredients and their respective quantities from which you can brew a bonafide 5-liter batch of sour beer.

  • 5lb of wheat malt
  • 6lb of pilsner malt
  • 75 ounces of Hallertau hops (around four of them)
  • ½ lb of rice hulls
  • 1 packet of standard ale yeast
  • 1 packet of Lambic blend yeast
  • Corn sugar
  • Slight more than five gallons of water

Initial Preparation

Like any good craft brewer, you should clean all your equipment before starting anything. Thoroughly rinse the pot and fermenter/keg and all other tools that are going to get in contact with the beer. A good practice is to treat your fermenter with a non-rinsing sanitizer to ensure you can brew the perfect batch of a sour beer.

Boiling the Mix

Like fermentation, boiling the mix is also pretty crucial in getting your beet batch’s sourness right. Put pilsner and wheat malts in the pot, add water and cook the mix at 152F for half an hour. After that, increase the flame a bit and boil the mixture. As the mash starts boiling over, add hops to the pot. Then simmer the mixture for the next one and a half hours.

It’s important to mention here that you don’t have to stress over starch conversion. The wild yeast in secondary fermentation will break down every last bit of complex starches.

Carrying Out Primary Fermentation

Once all the boiling and simmering is done, let the mix cool down. Then transfer it to the fermenter and add ale yeast to it. Seal up the fermenter for 14 days.

Carrying Out Secondary Fermentation

Once the fortnight duration has passed, you’ve to add the secondary fermenting agent to the wort. This phase is what makes beer delectably sour. This is also the step for which many people avoid brewing sour beer. Let’s see what involves in secondary fermentation and why many craft brewers consider it a deal-breaker.

During secondary fermentation, you’re supposed to add Lambic blend yeast to the wort. Lambic blend is essentially wild yeast that exhibits high contamination properties. By using it in your only fermenter, you can risk the taste and profile of all the future batches of non-sour beers.

Therefore, we’d recommend you transfer the mix to another container and barrel and then add a Lambic blend to it to protect your main fermenter from any long-lasting potential contamination. After adding the Lambic yeast to the wort, you need to keep it stored in any cold and dark place for at least six months. Storing it for longer won’t hurt. In fact, extended aging can improve the sourness of the batch.

When the period of secondary fermentation ends, open the barrel/fermenter and pour the mix into bottles via a funnel while filtering the solution with a strainer. At this point, you can also add corn sugar to the mix, depending on what taste profile you want it to assume.

Refrigerate the bottles and serve them chilled to trip on the intoxicating sourness of this all-grain beer.

How to Ensure Brewing of Sour Beer While Preventing Contamination?

As a craft brew enthusiast, you’d strive to prepare beers for their exact types and recipes. However, even the mild traces of wild yeast used in the making of sour beer can spoil other beers’ party. Therefore, you should take care of these things to ensure your sour beer preparation doesn’t affect future brews.

  • Carry out the secondary fermentation in a separate container. Make sure that the container is then only used for brewing sour beer. A plastic bucket or an old keg can serve as an exclusive secondary fermenter for sour beers.
  • Use a separate funnel and bottling wand to transfer the sour beer from the container to bottles.
  • Never add ale and Lambic yeast together. It’ll contaminate all your major brewing equipment.
  • You can use a single fermenting container if it’s made of stainless steel because it can be sanitized for all the wild yeast traces. However, replace any rubber or plastic used in its lining.

Our Final Thoughts

Brewing sour beer is not that difficult if you use the right set of ingredients and carry out the primary and secondary fermentation separately. The above discussion has also made it clear that it’s entirely possible for a craft brewer to prepare sour beer from their small setup without contaminating equipment and other beer batches.

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