Behind West Sixth’s Unfiltered Beer

West Sixth Brewery has made a conscious choice to never filter their beers. Why?
West Sixth Unfiltered Beer
West Sixths Local Brew|Photo by Jereme Zimmerman

Many breweries, particularly large-scale commercial breweries, filter some or all of their beers. The reasons are numerous, but, in essence, filtering removes any remaining particles from yeast or other ingredients. This improves clarity and halts fermentation, which is important for stabilizing beer for packaging. It also has the side effect of potentially dulling the beer’s flavor profile by removing subtle flavor characteristics. The methods for filtering beer vary, but a common technique is to use diatomaceous earth (DE) filters, which allow a small amount of DE and yeast particles to enter the beer, thus requiring further filtration through  additional filter media.

GOING FILTERLESS: On West Sixth’s website (westsixth.com) , head brewer, Robin Sither, explains that the staff has made a conscious decision not to filter, partially because DE is a regulated respiratory health hazard, and also due to the environmental footprint of filter media.  As he notes: “From the beginning, I’ve taken a strong stand as West Sixth’s head brewer (and owner) to never filter our beers. Filtration exposes the beer to a huge surface area of diatomaceous earth, paper sheets or cartridges. It can be done well, without too much detriment to the beer, but not typically at the craft brewing level of investment. There is a huge opportunity for oxygen pickup, potential taste taint from the filter media, damage to head retention and removal of certain hop characteristics.”

West Sixth’s secondary fermentation tank is a cylindroconical fermenter that is shaped like an inverted cone to make yeast extraction easier.

West Sixth’s secondary fermentation tank is a cylindroconical fermenter that is shaped like an inverted cone to make yeast extraction easier.

COLD CRASH CLARITY: In order to clarify the beer without filters, West Sixth employs some interesting techniques. One of these is “cold crashing” while in the secondary cylindroconical fermentation tank (it’s shaped like an inverted cone to enable ease of yeast extraction), which entails quickly dropping the temperature of the beer to approximately 32 degrees Fahrenheit once active fermentation has subsided. This essentially shocks any still-active yeast and forces it to drop to the bottom of the tank. 

The brewery also uses a centrifuge, a recent purchase that acts as a separator to run the unfiltered beer through a series of cone-shaped discs that spin at a high RPM. The force of the centrifugal motion, along with the short distance between the discs, leads to solids collecting on the inside of the discs, which are then discharged by a quick lifting of the discs off their base, causing the solids to “sling” out.

“To be fair,” said Sither, “it is not an apples-to-apples comparison because a separator will not make a beer super ‘brite’ like filtration…but we are only looking for a ‘near brite’ effect on the product, not a brilliantly clear presentation that comes at the potential expense of other characteristics of the beer.”

NEW PIONEER QUICK LINK:  To brew your own beer at home, visit www.ECKraus.com/offers/np.asp or call 1-800-841-7404

Related Stories: Growing A Hop Co-op Business