Over the centuries, different brewing cultures have developed a variety of approaches to the beer-making stage known as “mashing”—combining malted grains with hot water in order to extract the sugars and other nutrients that yeast will later consume and turn into sweet, sweet alcohol. The Germans, for instance, are known for the decoction mash; Belgian brewers established the turbid mash. And the British? They created the technique known as parti-gyle brewing.
At its most basic, parti-gyle brewing involves stuffing a mash tun full of malt and combining it with hot water to create a very sugary wort (or gyle) that’ll be used to make a high-ABV beer. After this first gyle is drawn off, the brewer adds another batch of water to the remaining grain, using the “second runnings” and small amount of sugar it contains to make a second, weaker beer. In essence, the process enables brewers to create two (or, as we’ll see below, more) beers from a single mash while wringing out every bit of sugar the grain has to offer.
“Think of a traditional coffee maker, where you run water through ground coffee,” says Richard Dube, brewmaster and cofounder at Braxton Brewing Co. in Covington, Kentucky. “If you’re in a hurry and instead of waiting for the entire quantity of water to go through the grind you take the first cup, that cup’s going to be very strong, because you’re pushing a smaller quantity of water through a greater quantity of coffee. Likewise, if you only drink what’s dripping after most of the pot has been made, it’s going to be very, very weak.”
To celebrate Braxton’s the second anniversary at the end of March, Dube and his fellow cofounder Evan Rouse released two beers brought to life through the parti-gyle technique. Mentor, made with the first runnings and named for Dube, is a dense, 10.5% ABV Belgian tripel. Mentee, Rouse’s beer, was brewed with the second runnings; it has a mere 3.4% ABV but gets a fruity snap through additions of guava and pomegranate.
Due to equipment restraints—Rouse says it requires, among other items, a four-vessel brewhouse—parti-gyle brewing is a rarity among modern brewers. But some do still employ the technique. In Belfast, Maine, Marshall Wharf Brewing Co. produces the 4.1% ABV Little Mayhem from the second runnings of Chaos Chaos, a brutish imperial stout. Chicago’s Revolution Brewing Co. turns the leftover mash sugars from its HuGene imperial porter into Wee Gene, a 4.7% ABV London porter. And Minnesota-based Surly Brewing has used the remnants of Darkness to spawn Damien, a black IPA, since 2011.
But there is perhaps no brewery in the world that makes parti-gyle brewing such an integral aspect of its process as Fuller’s Brewery in London. The brewery’s three flagship beers—ESB, London Pride and Chiswick Bitter—all come from the same mash. Fuller’s, however, treats parti-gyle a bit differently: Each wort that emerges from the mash goes through a boil with the same hop regimen. The finished beers are made distinct from one another through careful blending of the stronger and lesser-strength wort.