Cucumber adds a bright cucumber/green melon flavor to this Berliner weisse. Ehren Schmidt, Head Brewer Toolbox Brewing Company (Vista, California) scaled his recipe to homebrew size (5 gallons/19 liters) for us.
Brewhouse efficiency: 72%
6 lb (2.7 kg) 2-row malt
2 lb (907 g) white wheat malt
4 oz (113 g) acidulated malt
HOPS AND ADDITIONS SCHEDULE
0.15 oz (4 g) Sterling [14% AA] at 60 minutes
2.9 lb (1.4 kg) peeled cucumbers post fermentation
1 package Omega Yeast Labs 605 (Lacto Blend)
1 package American Ale Yeast
Mash at 145°F (63°C) for 45 minutes, then lauter into the boil kettle and pasteurize at 180°F (82°C) for 10 minutes.
Now is where it can get tricky. Transfer the wort into your preferred clean and sanitized souring vessel that is either purged with CO2 or has as little headspace as possible. Hold the wort at 98°F (37°C) and add the Lacto Blend. Acidification will usually occur in 18–24 hours.
When the desired level of acidity has been reached, boil the wort for 60 minutes following the hops schedule.
Cool the wort and pitch the American Ale Yeast, use yeast nutrient, and oxygenate. When fermentation is complete, transfer the beer onto the peeled cucumbers. Let the cucumbers sit in the beer for 24–48 hours at most.
Package the beer with 3.0 volumes of CO2.
The skin of the cucumber is where the most flavor is found, and if you don’t peel them before adding them to the recipe, you’ll end up with an undesirable vegetal/chlorophyll flavor. The peeled cucumbers provide more of a melon flavor (cantaloupe and honeydew) than green cucumber flavor. You’ll want to halve the cucumbers, then roughly chop them. Persian cucumbers provide the best flavor due to their thin and delicate skin, but if you peel the cucumbers you’re using, it really doesn’t matter.
The environment you sour in and the microbes you choose play off each other. Some species of Lactobacillus can produce butyric and isovaleric acid and other undesirable flavors in the presence of oxygen (for the most part, sanitation also plays a key role). Some species actually benefit from a bit of oxygen. Treat your quick souring vessel like any other fermentation vessel, sanitize, and isolate. Minimize the amount of headspace and if possible, blanket/purge with CO2.
From Berliner Weisse to Gose and points in between, quick souring is rapidly becoming the time-constrained brewer’s choice for building pleasant tartness on a schedule. In Craft Beer & Brewing Magazine®’s online course, Quick Souring Methods, Funkwerks Cofounder Gordon Schuck explains how to use Lactobacillus bacteria, experiment with sour mashing, test acidity levels, and more. Sign up today!