Fancy a slice of key lime pie?
How about as a beer?
For this year’s trans-Atlantic Rainbow Project, a collaborative brewing project that had U.K. and U.S. brewers working together to brew beers inspired by the colors of the rainbow, Hawkshead Brewery from Staveley, England and Crooked Stave from Denver, Colorado came together to brew their version of green.
The result? Key Lime Tau – a kettle-soured, lactose infused Golden Ale brewed with fresh lime zest and lemongrass.
Let’s break down the ingredients and recipe for this delicious dessert of a beer:
- A Golden Ale is a refreshing, hop-forward pale bitter beer that makes for the biscuity base layer.
- To create the zingy tartness of a key lime pie, natural yogurt was added into the mash kettle while the grains were steeping to introduce lactic acid-producing bacteria, Lactobacillus, that gives natural yogurt its tartness.
- To prevent the beer from becoming overly sour, lactose, or milk sugar, was added into the brew to bump up the sweetness. Yeast is not able to ferment lactose so it remains in the finished beer lending to a slightly sweeter taste and fuller mouthfeel.
- Then to give the beer the citrusy notes, fresh lime zest and lemongrass were added.
Add these ingredients to your brew at the appropriate times, and voila… in a few weeks, you’ll have a deliciously drinkable key lime pie!
So, then, why is this beer called Key Lime Tau?
This beer was brewed twice, both in England and in the States, and two times the mathematical constant pi (π, 3.14159…) is tau (τ). Plus, the beer’s conveniently brewed to 6.28% abv (two times 3.14!).
Dessert, beer, a little geeking out on mathematics – what more can you ask for when two great trans-Atlantic breweries come together in collaboration?
Have a slice of this one and get excited for next year’s Rainbow Project which will see U.K. breweries collaborate with some of New Zealand’s finest craft brewers.