How a Decanter Centrifuge Paid for Itself in Less Than a Year for Rhinegeist

Dry hopping has developed from being just a trend in recent years to an established technique for the entire brewing industry — especially in aspiring breweries from the craft beer scene. Rhinegeist Brewery — located in an area called Over-the-Rhine in Cincinnati, Ohio — has grown from 11,000 barrels a year in 2015 to more than 100,000 barrels in 2020.

Cole Hackbarth, Rhinegeist Brewery’s Director of Operations [pictured], said that with significant expansions and rapid growth, process optimization and separation reliability have become essential to stay competitive in the booming craft beer market.

When producing heavier beers, the material in the fermentation tanks becomes more difficult to separate. Using a machine that can handle effective separation for the tank bottoms is crucial.
In a modern fermentation tank — a unitank — the key feature is a steep conical bottom that collects all the heavy solids (yeast or dry hops). This can be separated as a thick slurry to leave a cleaner, more processable beer.

“A traditional disc stack centrifuge is great for light solids in that processable layer, but it cannot handle the heavy solids in the cone,” Hackbarth said. “The challenge was to find a machine that can do this. Even as you are dumping that stuff out, it looks thick, but you can still have up to 80% of that as beer and normally you are sending that down the drain or sending it to a waste treatment system. This does not help anybody, financially or environmentally. When Flottweg came to us with the decanter centrifuge, it was a game-changer for us.”

Using the decanter, Rhinegeist was now able to recover the beer from the heavily hopped solids, but it also helped to pull it out of the municipal waste stream in the system. “We are just now getting into surcharges and having to work with them on the waste treatment side,” he said. “So being able to sidestream all of that saves us a lot.”

Rhinegeist’s flagship IPA accounts for more than 50% of production. The brewery is experiencing more than a 10% yield increase per batch, thanks to the decanter technology.

“When you are doing 50,000-to-60,000 barrels a year, it adds up pretty quickly,” Hackbarth said. “The machine paid for itself in less than a year, so it was kind of a no-brainer. We got the Z2E test unit, and it worked great. So, we went ahead and got a Z4E and let it rip!”

Rhinegeist produces only unfiltered products without any polish filtration and is using the decanter for all separation.

“That has obviously helped to take a lot of load off the disc stack centrifuge,” Hackbarth said. “Previously, we were running our disc stack centrifuge around 40-to-80 barrels an hour, at best. Now, with the decanter, we can have some of our unfiltered UC IPAs up to 140 barrels an hour — which is crazy! It has increased our throughput, been easier on the machine, and has fewer discharges on the disc stack centrifuge. This means there is less maintenance overall and better reliability.”

Hackbarth said training for the new equipment was seamless, and the benefits have been obvious since installation while the flavor profile has been unaffected by the change in technology.

“The beer is as good as it has ever been,” he said. “We are removing more hop solids, so in some of the ‘hazies’ there is less of that yeast bite and less of that little hop-bitterness. Our dry-hopping process is a recirculation through a high-shear pump, so we pulverize all of our hops and extract all the oil we can. When it hits the decanter, we are pulling out those leftover solids.”

Hackbarth offered some advice for other breweries who may consider using decanters.

“Just look at your portfolio mix,” he advised. “How many hoppy beers are you producing? If at least half of your portfolio or more is hoppy, which most breweries probably are, I think a decanter is probably a smart choice. In fact, Flottweg has the Z2E, which is a nice little skid-mounted system. It is pretty ‘plug-and-play,’ and I think that is a great option for a small regional player and craft brewer.”

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