Brewing with Vegetables

There are hundreds of recipes designed to sneak vegetables into kids’ food: Beet-chocolate cupcakes or cauliflower-crust pizza, anyone? What if you want a more adult solution to vegetable consumption? Whereas fruit has a storied brewing history from Belgian krieks to American raspberry wheats, vegetable beers are less prolific but often no less delicious!

In 2015, the Tax and Trade Bureau (TTB) expanded the list of “traditional” ingredients that American commercial breweries can use without scrutiny. Of 88 entries, over half are fruit, while only two are vegetables: Sweet potatoes and kale.¹ Craft brewers are ravenous for novel ideas, unique flavors, and exciting aromatics. Vegetables are one such area gaining popularity with adventurous brewers, especially those with an eye towards local ingredients.

A fruit is the edible part of a plant developed from a flower; fruit is the sweet fleshy part that surrounds the seeds (or in the case of some berries is surrounded by seeds). Vegetables are cultivated for other edible plant parts, such as roots, leaves, and stems. Some “culinary vegetables” commonly associated with beer such as chile peppers and pumpkins are botanically classified as fruit. This article will explore the use of true vegetables. The key to unlocking the potential of a vegetable is in determining whether to treat it like a starchy adjunct grain, a fermentable fruit, or as hops.

Like Adjunct Grain

This group includes many root vegetables, like potatoes and carrots. Their flavors tend to be subtle, so plan to use large amounts to capture the taste and if you spice, be gentle! Many varieties of squash contain less than 10% starch and as a result can bypass the mash. Conversely, most root vegetables should be cooked and then mashed with enzymatic malts because of their significantly higher starch content.2 Pureeing or physically mashing the cooked starchy vegetable will improve conversion and extraction but can also result in an impermeable grain bed, so add rice hulls!

My friend Erich Streckfuss (Assistant Brewer at District ChopHouse in Washington, DC) has homebrewed several batches with smoked sweet potatoes. He chose the technique because he admits, “I don’t trust myself to smoke my own malt.” Erich suggests using around 0.5 lb. per gallon (60 g/L). He par-bakes the sweet potatoes to soften, before slicing into 3⁄4-inch (2-cm) thick rounds. He then scores the surface to increase surface area before smoking over wood chips for five minutes per side. Before adding the smoked sweet potatoes to the mash he pulses them in a food processor. Erich has been particularly fond of the results in malty English styles where they add an “Old World rustic smokiness” along with color and fermentables.

Like Fruit

If a vegetable feels more at home in a pie or salad rather than a stew, it is safe to treat as a fruit. Where aromatics are the goal, post-fermentation additions avoiding the heat of the boil and the CO2 scrubbing of fermentation yield the truest flavor profiles. If you prefer the aroma of the vegetable cooked, you can stew it down or roast it to concentrate the flavor.

Rhubarb looks like red celery, but tastes more like green apple. It has a sharp bite of acidity and a pleasantly berry-orchard flavor. My friend Sara Bondioli (Erich’s wife) has brewed five batches of Strawberry-Rhubarb Saison over the last three years, so I couldn’t think of anyone better to ask for tips. Her initial approach was to chop 0.5 lb. per gallon (60 g/L) of rhubarb and 1 lb. per gallon (120 g/L) of strawberries, followed by a quick dip in StarSan, and then into the freezer where ice crystals puncture the cell walls. When the base beer finished fermentation, she racked onto the partially-defrosted rhubarb and strawberries for a two-week secondary fermentation.

Looking to improve the extraction for her second batch she tried pureeing. While this improved the strawberries, it led Sara to discover two reasons not to puree stringy vegetables: “One, it doesn’t puree well, and gets caught up in the blender blades. Two, it’s a mess when you’re trying to rack the beer off it later.” Needless to say, she is back to chopping rhubarb! Sara describes the finished beer as “slightly tart from the rhubarb with hints of strawberry in the aroma and flavor.”

Beet is a vegetable that has gotten a public image overhaul since I was young. Beets impart the flavor of fresh soil and a fantastic magenta color to beer. Beets were my answer to rescue a Brett saison with objectionable sulfur. I hoped the renewed fermentation from the sugar in the beets would drive off the volatile aromatics while the aromatics would complement the spicy and earthy wild yeast character. I peeled and shredded three beets on a box grater and racked five gallons (19 L) of beer onto it for an extended secondary. Fortunately, it worked! The beets provided enough fermentables to drive off the sulfur while imparting a loamy complexity and vibrant color!

Todd Boera of Fonta Flora Brewery (Morganton, North Carolina) noted that his Beets, Rhymes, and Life saison loses much of its color during bottle conditioning, but not in the keg. Neither of us has a great explanation for why this is, but consider kegging if you don’t want to lose the color.

Like Hops

Leafy greens are an underexplored area of beer flavoring (despite the apparent popularity of kale with the TTB). Many traditional greens (e.g., arugula, dandelion greens) add mild bitterness. They could be added to provide a unique dimension to an IPA, or as a substitute for hops in a gruit. My former BYO co-author Nathan Zeender (“The Cult of American Saison” in the July-August 2011 issue) adds dried dandelion greens along with roasted dandelion roots to Right Proper’s (Washington, DC) Teeth of Lions Rule the Divine. The leaves add a green chlorophyll flavor and both leaves and roots contribute bitterness that doesn’t inhibit their house Lactobacillus. He dry hops the beer with Centennial and Chinook to go with the “dandelion vibe.”

Green vegetables are one of the least initially appealing choices for beer. Broccoli? Cabbage? Doesn’t sound like a beer I want to drink! However, if you find yourself in the northern part of the mitten (of Michigan) in spring, check out Spear Beer from Right Brain. It starts as a relatively simple golden ale with mostly Pilsner malt. 24 hours into fermentation they add 80 lbs. (36 kg) of grilled fresh asparagus that has been grilled over a gas flame. A final touch of lemon zest brightens up the flavor. This is a unique approach to bring local and seasonal character to a beer, and the flavors work surprisingly well!

Unfortunately, adding vegetables to beer squanders their health benefits (including much of the fiber and certain vitamins) but their savory flavors and aromatics often survive to create seasonal beers linked to the growing season!

3 Hieronymus, Stan. Brewing Local (Brewer’s Publications, 2016)
4 Josephson, Marika, Kleidon, Aaron, and Tockstein, Ryan. The Homebrewer’s Almanac (Countryman Press, 2016)

Beets by Drie Saison

(5 gallons/19 L, all-grain)
OG = 1.043 FG = 1.001
IBU = 22 SRM = 3 ABV = 5.5%

8.75 lbs. (4 kg) Weyermann Barke Pilsner malt
6 AAU Saphir hops (65 min.) (2 oz./57 g at 3% alpha acids)
3 medium beets (post-fermentation)
1⁄2 Whirlfloc tablet (5 min.)
1⁄2 tsp. yeast nutrient (5 min.)
Bootleg Biology BBXMAD1 (Mad Fermentationist Saison Blend)

Mash at 152 °F (67 °C) for 30 minutes. Collect wort and boil for 65 minutes, adding hops as scheduled. Cool to 72 °F (22 °C) and transfer wort to a fermenter. Aerate and pitch (if suggested blend isn’t available use a saison strain and fruity Brettanomyces of your choice). Maintain fermentation temperature around 72 °F (22 °C) until fermentation slows, and then warm to 80 °F (27 °C) to ensure complete attenuation. Add 14 oz. (400 g) of shredded beets. Age until it reaches your desired flavor and gravity readings are stable month-over-month. Package aiming for 2.7 volume of CO2.

Extract Option:
Replace malt with 5.5 lbs. (2.5 kg) of Pilsner liquid malt extract or 4.75 lbs. (2.15 kg) Pilsner dried malt extract. Skip directly to the boil and follow the all-grain version.

Issue: July-August 2017