Add Depth to Your Sours

After reading the analytical tests from several German Berliner Weisse beers, it was apparent that acetic acid plays a role in 'enhancing' the flavor in good sour beers. In the case of those Berliner Weisse's, they had between 0.1 and 0.6 grams of acetic acid per liter of beer with most samples being above 0.3 g/L.

Since souring with acetobactor or even brettanomyces can be problematic and difficult to control, dosing a beer with known quantities of purified acetic acid makes sense. A readily available form is distilled vinegar. It is typically sold with 5% strength.

After a few calculations, that 0.3 to 0.6 g/L acetic acid value was converted into usable volumes of 5% distilled vinegar. Dosing the vinegar at 6 to 12 mL per liter of beer will produce the desired 0.3 to 0.6 g/L acetic acid in the beer.

Wanting to avoid steering Bru'n Water users wrong, I tested the 0.3 g/L acetic acid concentration by adding 6 mL of distilled vinegar to a liter of my alkaline tap water. I couldn't taste the acetic flavor at all. Then I repeated the experiment using RO water to see if low alkalinity would help the acid flavor come through. I was JUST able to detect the flavor at that low-end dosage. So it does appear that this low end concentration is an appropriate starting point for your experiments.

So, if you find that your next sour beer is lacking complexity, try dosing the beer with distilled vinegar. For you US users, that 6 to 12 mL/L rate translates to 23 to 45 mL distilled vinegar per gallon of beer. Try it in your glass before committing your whole batch to it, but it could make a real difference!