Beer Fact Friday: The Centrifuge
Ever felt like you’re being pushed to the door of your car as it rounds a tight curve? What you’re feeling is centrifugal force—force that arises from inertia and acts outward on an object moving around a center.
A brewery centrifuge makes use of this force to filter beer. Though these devices are very expensive and look pretty imposing, the way they operate is actually fairly simple: They spin the beer very quickly to remove heavy particles. This works because despite looking like one homogenous liquid, beer is actually made up of many different compounds and particles—yeast, sugar, and hop plant matter among them—suspended in water. When a centrifuge spins the liquid within a round chamber, the heaviest components of the liquid are pushed toward the rotation chamber’s outer wall, while the lighter components (water and alcohol, mainly) stay closer to the center axis. Once the heavier particles have been spun to the outside of the chamber, the clear, filtered beer is drained from the centrifuge and sent to another area of the brewery to be packaged inside kegs, bottles, or cans—or, in some cases, to another filter to be polished further.
The beer-drinking public’s current love for haziness notwithstanding, there are plenty of benefits to filtering beer with a centrifuge. For beers that are packaged unfiltered, such as our White Ale, the centrifuge can be adjusted to separate out yeast cells while leaving other particles alone, ensuring the beer isn’t loaded with organisms that can continue to ferment the beer and change its flavor. If you’re planning to filter your beer with diatomaceous earth, spinning out the large particles with a centrifuge beforehand can make the process much, much more efficient. A centrifuge can also be used to eliminate proteins and other materials that cause beer to oxidize, meaning it’s an essential tool for brewers who want their beer to taste better, longer.