Beer Fact Friday: Parti-Gyle
Problem: You’re a brewer who needs to put two new beers on draft later this month, but you only have enough malt for a single batch. The solution: Parti-gyle brewing, the process of making multiple beers from a single mash.
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 portion of sugary liquid—sometimes referred to as the “first runnings”—is drawn off, the brewer adds *more* water to the remaining grain. This water extracts the small amount of sugar left in the grain, and the less sugary “second runnings” are then used to make a second, weaker beer.
Still confused? Picture a standard drip coffee maker, in which water is run through ground coffee. If you grab the first cup that comes through the grind, 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 weaker in both flavor and caffeine. In essence, parti-gyle brewing enables brewers to create two (or more) beers from a single mash while wringing out every bit of sugar the grain has to offer.
Though made with the same grain, the beers created from a single parti-gyle are also usually quite different from one another. (The first runnings of a parti-gyle might be used to make a barleywine, while the weaker second runnings produce a low-ABV Special Bitter, for example. Some styles have even developed as the result of this practice: Historically, lighter Scottish beers such as Scottish Light Ale were made using the second runnings from stronger beers like Scottish Export or Wee Heavy.
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