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Austin brewery releases a bright purple beer to celebrate spring

Arianna Auber
Thirsty Planet Brewery's new seasonal, Cosmic Butterfly Kettle Sour, clocks in at a sessionable 3.9 percent ABV and comes in a bright purple color. [Contributed]

Beers generally range in color from light straw to midnight black — though, of course, they might also take strawberry hues if fruit has been added or have a shamrock shade of green around St. Patrick's Day. But has any beer come out looking like the vivid purple of a Lisa Frank design?

Well, there's a first time for everything, as they say. Thirsty Planet Brewery has released a new seasonal beer, the Cosmic Butterfly Kettle Sour, in bottles. And it's purple thanks to the addition of one particular ingredient: the butterfly pea flower native to Thailand and Malaysia.

Bartenders at craft cocktails bars have gravitated toward the butterfly pea flower in the past couple of years to treat customers to what looks like a boozy science experiment. In the form of a tea or tincture, the vibrantly colored butterfly pea flower turns clear liquid blue. Add an acid to that mixture, such as citrus juice, and presto chango — the drink is now purple. (High pH ingredients, like green tea, make it pink.)

Austin bars such as the Roosevelt Room and the Four Seasons' Lobby Bar (now called Live Oak) have experimented with butterfly pea flower as an ingredient in their cocktails, but its chameleon characteristics have now been co-opted for local beer, too. The Cosmic Butterfly isn't color-changing, pouring bright purple straight from the bottle.

Thirsty Planet made the beer originally last spring as one of the small-batch options in its pilot program, the Special Brewskis. The Berliner Weisse-style Cosmic Butterfly is the first of those Special Brewskis to move into bottles, according to the brewery.

"It's a lightly tart ale with a crisp malt character fluttering with lemon and tea notes," Thirsty Planet writes on Instagram — because, in case you were wondering, yes, the butterfly pea flower does contribute actual flavor in addition to that memorable color, and it's pleasant.

Find the beer in the Austin market, including HEB stores, by the end of this week. Although Thirsty Planet's facility is on prime real estate on South Congress Avenue, the on-site taproom is still a work-in-progress.