An operating brewery is filled with the din of industrious creation: The thrum and slam of the centrifuge, the whirr of a bottling line, and the constant soundtrack of heavy metal or hip-hop spilling from speakers—all mingling to create the sonic landscape of the craft brewery. Yet one sound cuts through the noise, snapping workers into frenzied action and, some say, scarring their memories.
The scream of a pump that’s run dry is the stuff of brewers’ nightmares.
Pumps are intrinsic to a brewery. After all, there are all sorts of liquids that need to get from one place to another, from water to wort, from yeast slurry to beer, plus all the chemicals and cleanup afterward. Unless you can get gravity or gas pressure to move the fluids, you need to apply some mechanical work, be it a bucket brigade or a progressing cavity pump. There is a whole arsenal of pumps at the brewer’s disposal for whatever solution they require.
Because that’s what pumps are: solutions to specific problems. In a brewery, most common of these problems are of the “liquid in vessel A needs to be in vessel B” variety. (Like when the wort in the lauter tun needs to be in the boil kettle, or hot wort in the kettle needs to move to the fermentation vessel, or all the beer in the brite tank needs to be supplied to the bottling line at high pressure.)
The most common pump to handle the transferring tasks in the brewery—and the one infamous for its piercing death knell—is the centrifugal impeller pump.
Pump Primer
“They’re the workhorse at most breweries,” says Zeke Bogan, director of brewing operations at Los Angeles Ale Works in Hawthorne, California. Whether built into a brewhouse manifold or mounted on a cart to move around the brewery, centrifugal pumps are very effective at moving liquids.
Before Bogan manned the brew deck in Hawthorne, he spent 15 years in various roles at Bell’s Brewery in Kalamazoo, Michigan. While the difference in scales between the two breweries was considerable, Bogan says both breweries relied on centrifugal pumps for much of their liquid-transfer needs.
“The motors were bigger, the carts were heavier, and you had to push them further,” he says, “but [centrifugal pumps] are doing the same thing, just at different volumes.”
Pumps in their many forms convert mechanical action to hydraulic energy, and in most cases, the necessary mechanical action is provided by an electric motor. In centrifugal pumps, the motor spins the pump’s impeller—a disk ribbed with vanes that accelerates liquid from the inlet near the center of the impeller to the outside of the disk through centrifugal force. The faster the impeller spins, the more pressure it builds. These are relatively simple pump designs, yet there are countless variations in impeller design, housing, and motor size to provide the required head pressure, flow rate, and so on.
For all the centrifugal pump’s simplicity and ubiquity, there are some downsides that require consideration when used in the brewery. The high shear-forces inside a centrifugal pump head can be hard on finished beer or on yeast slurries, causing foaming or oxygen pickup in beer or cell damage in yeast. However, a bigger concern in the brewery is keeping them in good working order.
Centrifugal pumps are designed to be cooled mostly by the liquid moving through the pump, so running them dry or with the outlet closed can cause them to overheat. The latter is called “dead heading” the pump; with nowhere to go, the liquid inside the pump just circulates internally, causing heat to build up. This can damage both the liquid itself and the pump’s own internal mechanisms. A pump can overheat in a matter of minutes, and this is one cause of the previously mentioned screeching and wailing.
Another noisy failure mode that can occur in a pump is called cavitation. Caused when water changes state from liquid to gas (or the reverse) as it experiences pressure and heat differentials, the rapid collapse of the bubbles creates tiny shock waves that can cause outsized damage to delicate machine parts. From accelerating wear to completely destroying an impeller or pump seal, cavitation results in countless bad days for brewers and maintenance techs every year.
The relative simplicity, low cost, and ease of operation have led to the centrifugal pump’s dominance in small breweries; they’re the Swiss army knives in a brewery’s pumping toolbox. Sometimes, however, you need a scalpel.
Photo: Courtesy Fonta Flora Brewery
Specialized Tools for Specific Tasks
As a brewery grows in volume and in the sophistication of its process, its focus on efficiency also grows. What may cost a small brewpub a few extra dollars a year in materials, utilities, or wear and tear can cost a regional production brewery much, much more. Margins and competition are tight today, and the savvy brewer is always looking for added efficiency or a way to streamline a process.
This is where the number of more specialized pump designs come into the brewery equation. Many of these impeller alternatives are known as positive displacement (PD) pumps. Instead of using a spinning rotor to energize the liquid, they move a measured volume of liquid (or slurry) through the pump’s mechanism. There are many different styles of PD pumps. Whether they’re transporting delicate yeast slurries, moving tons of soggy spent grain, or supplying product to a high-pressure bottling line, there’s a perfect pump for the job.
Compared to the high-speed operation of the centrifugal pumps, the more gentle mechanisms of the PD family of pumps make them ideal choices when finesse is more important than flat-out flow rate, or when the liquid is thick, sticky, or carrying solids that would impede centrifugal pumps.
True to their name, the mechanical action of air-operated double-diaphragm (AODD) pumps is generated with compressed air. Often found in wineries and barrel houses, AODD pumps are lightweight, compact, and efficient pumps well-suited to moving delicate liquids.
Peristaltic pumps use a flexible hose with cams positioned on the outside that compress the hose and push the fluid within down the line. Each rotation of the cam will move a specific quantity of liquid a specific distance. In addition to yeast handling, they can be used for dosing cleaning chemicals in CIP systems or for moving thick slurries around the brewery. “Peristaltic pumps are used for yeast dosing,” says Seán Diffley, engineering director at Maine’s Allagash, “as they are gentle and precise, allowing for accurate dosing of small amounts of yeast.”
As Allagash has grown over the past decade, Diffley says they’ve added more esoteric pumps at specific nodes in their process. These range from a liquid ring vacuum pump to serve the vacuum bottle fillers to the Seepex progressive cavity pump that handles spent grain and spent yeast removal. (He cites the latter as crucial to the brewery’s increased throughput.) The latter pump is like the modern version of one of humanity’s first water-moving machines: the twisty Archimedes screw.
“Allagash’s use of different pump types reflects our commitment to using the right tool for the job, ensuring that each step in the brewing process is optimized for efficiency and quality,” Diffley says.
Photo: Ash Patino/Generic Brand Human
Deep Well of Knowledge
With so many different types and styles of pump available to the brewer, identifying the best one to solve a problem isn’t always simple. While brewer’s schools such as the Master Brewers Association of the Americas and Siebel cover the theoretical side of pumps in coursework, most brewers learn the ins and outs of using them in the brewery while on the job.
“There’s a lot of institutional knowledge passed from brewer to brewer,” says Bogan at Los Angeles Ale Works. Yet taking courses and reading up on the technical side of breweries remains a good way to get a leg up in the industry. “I know more about pumps now than I ever thought I would,” he says.
This brewer-to-brewer training can also lead to an unconscious resistance to new solutions.
“Brewers can get tunnel vision regarding the equipment they already know,” says Michael Caviness, general manager of TCW Equipment & Systems in Santa Rosa, California. “There’s a lot of jargon and a lot of misunderstandings about different pumps.”
TCW supplies machinery and equipment to both wineries and breweries in California’s Napa Valley. Caviness is happy to help brewers find the right pump to solve their process predicaments—so much so that he’s authored a whole series of pump-focused blog posts for the TCW website. These posts demystify the options and clarify the jargon, and online he’s often looking for opportunities to share his pump knowledge with brewers.
Yet while sites such as Reddit may have answers to your pumping questions, and while coursework and technical articles can strengthen your theoretical foundation, there is no substitute for hands-on experience.
Curtis Holmes is plant manager at Alaskan Brewing in Juneau, and he’s been with them since 1991. Besides the two-week short course at Siebel and some “various training opportunities” at the brewery over the past 30 years, he’s learned it all by doing.
And the man can talk pumps.
We speak at length about all the pumps that Alaskan has added over the years. (“The older the brewery, the more pumps it has,” he says.) Holmes details the pros and cons of each and discusses their various maintenance requirements—and he reminds us that the brewing industry is great at knowledge sharing. He recommends talking to other brewers at conferences or via online fora. He also suggests leaning on pump suppliers and their reps for detailed solutions for specific problems.
“Those guys know the products, and they know the math,” he says.
Science Behind the Artistry
It’s cliché to say brewing is a blend of artistry and of science, but that doesn’t make it any less true. It’s an axiom that displays its depth each time I dive into the details of another tool or piece of equipment in the brewery. From the biochemistry of yeast propagation to the chemistry of malt kilning to the fluid dynamics of various pump architectures, brewing encompasses a wide swath of scientific disciplines. Brewing technology advances hand in hand with human civilization, either being driven by advancements in scientific understanding or, in many cases, driving those advancements.
What separates a journeyman brewer from a master isn’t a job title or a brewing degree, but a deeply held understanding of, and respect for, the tiniest of details and variables in the brewing process. A master deftly balances technical capabilities with artistic vision, all under the constraints and demands of operating a business.
A fancy new pump is never going make a bad beer into a great one, but it can still do a lot for the brewery: It can smooth out rough edges in a brewery’s production; it can add a specific new capability or new degree of precision to a certain process; it can increase throughput and capacity; it can reduce a labor pain point; and it can increase efficiency.
Pumps are a problem-solving force, and the right application of this force can help elevate a brewery above all the noise in today’s marketplace.