How Do Centrifuges Clarify Liquids and Beverages?
Clarification is an extremely important step in beverage production. Particulate impurities (dirt and grit, yeast bodies, udder cells, or anything else) need to be separated for removal prior to homogenization and pasteurization of juice or milk. Even minimally processed beverages (like beer, kombucha, and cold-press juices) need to be relatively free of yeast bodies, bacteria, and the remains of microorganisms if you want to ensure consistent quality and shelf life.
Traditionally, beverage producers have approached clarification using a combination of sedimentation, flocculation agents (like isinglass), and filter-based separation solutions, such as sieve operations, diatomaceous earth (DE) beds, and other disposable media and membrane filters.
But these often fall short. As particles—like pulp or yeast bodies—collect on the filter media the entire solutions’ performance shifts. This isn’t just a matter of slowing the filtration and sedimentation steps, leading to longer batch times. As sludge accumulates in the filter medium, you begin filtering out elements you want to preserve and accentuate in your beverages. Ions, flavonoids, antioxidants, and flavoring elements are lost.
And even if everything works ideally, you still end up with some perfectly usable beverage trapped in the filter sludge or filtration medium. Beer clarification is a good example. Filters have trouble handling the high solids content of some beer styles. Not only do the filters clog quickly, but the hops oils become bound up in the sediment. In short, you worked hard to capture a distinct set of aromas and flavor only to “throw the baby away with the bath water” in the process of getting it from tank to bottle.
Centrifugal separators approach clarification entirely differently—protecting flavors while driving down labor and increasing yields.
Centrifugal Clarifiers for Food and Beverage
A centrifuge-based clarifier uses centrifugal force, instead of a filtration barrier, to separate solid particles from your liquids. It does this by feeding the unfiltered beverage into the centrifuge bowl distributor. That bowl contains a set of thin conical baffles (often called the “disc stack”) that spin along with the chamber. This spinning creates a tremendous force that, along with the specific shape and arrangement of the disc baffles, separates the liquid and particle impurities by density. It then channels them into separate streams. This allows for the continuous separation, clarification, and processing of liquids.
In many cases centrifugation alone will outperform other filtration systems when it comes to particle separation and extraction. In every case, centrifugation prior to other filtration will improve outcomes and significantly extend the life of expensive filters.
Consider that hop-heavy beer. By using a centrifugal separator (instead of more traditional media-based filtration) you can easily extract the hop material while leaving the hop oils in the beer.
A centrifuge also noticeably increases production. For example, beer is regularly lost because it remains bound up in the sediment that collects in the bottom of conical fermenter tanks. A centrifuge will extract that—usually netting an additional 7 to 12 percent from every batch. Juice clarification enjoys similar gains from centrifugation. Most juice clarification processes lose a significant volume of juice during decanting. A high speed disc stack centrifuge can recover that. All told, when you factor in reduced batch time, increased quality and shelf life, and increased yields, a centrifugal clarifier can improve beverage production by 30 to 50 percent overall.