Recapturing CO2: It’s a Gas

Brewers are dumping their blow-off buckets and reusing precious carbon dioxide rather than releasing it into the atmosphere. The benefits include cost savings, reducing greenhouse emissions—and, some say, better beer.

John M. Verive Apr 8, 2022 - 15 min read

Recapturing CO2: It’s a Gas Primary Image

Gregg Spickler, director of brewing operations at Alamo Brewing in San Antonio, connects the foam trap between a fermentor and the Earthly Labs CO2 recapture system. Photo: Courtesy Earthly Labs

Do you know where the bubbles in your beer come from? It may not be exactly where you think.

Yeast, of course, produces the carbon dioxide (CO2) along with ethanol and all those tasty esters and phenols. However, only a small percentage of craft beer contains carbon dioxide produced during its own fermentation. Most of that gas escapes into the atmosphere, bubbling away in blow-off buckets and adding to greenhouse-gas emissions. Most canned, bottled, and kegged beer is force-carbonated and packaged with bulk CO2, which local suppliers deliver to the brewery at regular intervals.

Busy breweries tend to operate like machines, and using CO2 from bulk suppliers is one of those cogs in the machine that just works. Few give much thought to all that gas produced by the yeast. It just bubbles out into the atmosphere because it’s easy and relatively cheap to purchase CO2 from a third party. After all, gas is gas. Right?

Seen in a different light, it’s the kind of absurd inefficiency in the system that would make Rube Goldberg proud. Instead of using everything the yeast creates, a brewer discards hundreds of pounds of CO2 as a by-product of each fermentation—only to turn around and buy someone else’s by-product.


Because that’s where all that bulk CO2 comes from: It’s a by-product of other industries. In much of the United States, bulk CO2 comes from the process that turns corn into ethanol fuel. Natural-gas mining and the refining of petroleum account for another big chunk of it, while in the United Kingdom most CO2 comes from fertilizer production. While it’s true that a CO2 molecule is a CO2 molecule whether it came from a brewery or a fertilizer plant, it isn’t that simple when we talk about getting that gas into a beer.

Carbon Dioxide Recapture

How can breweries harness the full potential of fermentation and close that loop? The biggest roadblock for a small brewery using the CO2 it produces is mainly one of process.

It’s certainly possible to naturally carbonate beer—even draft beer. In Germany, where adding external CO2 runs afoul of the beer purity laws, natural carbonation is achieved with a spunding valve during fermentation (see “Gearhead: The Force Behind the Fizz,” Interest in spunding among American brewers appears to be rising alongside that of traditional lager, and it’s something that even homebrewers can do.

For larger breweries making hundreds of thousands of barrels a year, CO2 recapture systems are more common—and they are an example of how, even when it comes to sustainability, economies of scale favor the giants with processes and purchasing power unavailable to smaller breweries. CO2 recapture systems are seven-figure capital investments offered by the likes of GEA and Atlas Copco. They require hundreds of square feet of space and dedicated operators to keep them running. When you weigh that against the ease and affordability of bulk CO2, it’s an easy decision to rely on bulk gas.

However, as sustainability practices gain traction among independent brewers and the focus on CO2 emissions intensifies, more brewers are looking for ways to use the gas they already make. The problem: Until recently, there wasn’t an economically feasible solution for a brewery making less than 100,000 barrels annually.


Perhaps the first craft brewery to implement a CO2 recapture system was Alaskan in Juneau. The remoteness of the brewery meant that bulk CO2 was much more expensive than in the Lower 48. As cofounder Marcy Larson says, “Where we are drives what we do.” The brewery added the CO2 recapture capability with a solution offered by the Gemany-based Pentair back in the 1990s. Larson says she’s surprised the technology hasn’t caught on more widely among other craft brewers.

Across some 3,000 miles of Pacific Ocean on the island of Maui, another brewer is using a similar recapture plant from Pentair. Maui Brewing is an industry leader in sustainability initiatives, from water-use reductions to solar power to CO2 recapture. And while the positive environmental aspects of the efforts are primary, there are other considerations at play.

“Maui has a shitty electrical grid,” says Garret Marrero, the brewery’s cofounder and CEO. With the abundant sunshine in the tropics, solar power was an easy call to make. A sizeable array of panels and Tesla Powerpack batteries comprise the brewery’s “microgrid,” which is now almost independent from Maui’s electrical utility.

Hawaii also is one of the most expensive CO2 markets in the country, and that cost has doubled in Maui’s 16 years of brewing. Limited local production also means shortages and short-term price increases are not uncommon. That cost and volatility drove Marrero to look into CO2 recapture systems. He began to work with Pentair, which was developing their Haffmans CO2mpactBrew recovery system.

With a footprint of a 40-foot shipping container, the Haffmans system has offset Maui Brewing’s CO2 requirements but hasn’t completely replaced the need for bulk CO2 deliveries. The system is complex, requires regular maintenance, is prone to downtime, and can collect gas only from a subset of the brewery’s fermentations. “It can be frustrating at times, but we knew what we were getting into,” Marrero says about being an early adopter of the tech, “and we feel that it’s our duty to do more with less.”


The potential cost savings, independence from local suppliers, and direct reduction of CO2 emissions all combined to make CO2 recapture a worthwhile project for Maui Brewing.

As I was talking to Marrero, he mentioned that he was actually in Wyoming on his way to Roadhouse Brewing in Jackson Hole for a collaboration. He also mentioned their smaller-scale CO2 recapture system from Earthly Labs.

Recapture Solutions for Smaller Breweries

When I started my investigation into how craft breweries were approaching CO2 recapture, I expected an assortment of available technologies and solutions. The reality is that the low cost and wide availability of bulk CO2 meant that not many brewers were willing to invest in recapture equipment, while manufacturers were focused on the largest craft breweries.

Earthly Labs aims to change that.

Founded in 2016 in Texas on the back of proprietary technology that purifies and dehydrates captured gas then compresses it for storage, Earthly Labs has pushed to get their plug-and-play recapture system—dubbed the CiCi—into as many craft breweries as possible. They began with the local market in Austin and are now expanding to other beer hotspots around the country.


Jon Courtois, production manager at Roadhouse in Jackson Hole, was eager to talk about his experience with Earthly Labs and the CiCi system that’s installed at the Roadhouse production brewery. “It’s a no-brainer solution,” he says, “And it didn’t take a lot to convince the brewery leadership.”

From the outset, cofounders Colby Cox and Gavin Fine set up Roadhouse with a commitment to sustainability and respect for the stunning natural environment that surrounds Jackson Hole. The Earthly Labs CiCi fits with that commitment while saving money and improving the safety of their brewery. They also insist that it improves the flavor of their beer.

“It’s a feather in our cap, a point of pride,” Courtois says. In an Earthly Labs informational webinar recorded recently, he estimates that the brewery will recoup the cost of the CiCi unit—about $150,000 after delivery and installation—in just three years. That’s without considering the possibility of selling any excess CO2 the brewery recaptures on the system.

The Earthly Labs system includes a few discrete components. The main unit—about the size of a commercial refrigerator—contains the dehydrator and compressor at the heart of the setup, along with an array of sensors that control the process; a pair of foam traps connected between the fermentation vessels and the CiCi prevent solids from entering the system. During active fermentation, CO2 travels through the foam traps and into the CiCi. The unit dries the gas, scrubs it of impurities, and compresses it into a storage flask for use later in the brewing process.

Courtois says the most surprising thing to him about the system wasn’t the ease of installation and setup—two days after delivery, it was up and running—nor the efficiency of capturing what was previously just a waste product. The biggest surprise, he says, was the qualitative improvements that the recaptured CO2 made to Roadhouse’s beers.


“Without question, the beer is better,” Courtois says. “You have to see it to believe it.”

Initially, the brewers and production staff were skeptical of claims that the system would improve quality. However, extensive sensory panels and analysis of both the recaptured gas and beer carbonated with it have convinced them.

The key is in the purity of the CO2 that the CiCi sequesters. While food-grade bulk CO2 is about 99.9 percent pure, that 0.1 percent of stuff that’s not carbon dioxide can include hydrocarbons, sensory-active molecules, and oxygen. That doesn’t sound like much, but in an article titled, “Understanding and Ensuring CO2 Supply Quality for Brewery Use,” the Brewers Association puts that into context: That 0.1 percent equates to 1,000 parts per million—a concentration that is one to four orders of magnitude higher than many of the flavor-active components in hops.

The biggest worry for brewers might be the trace oxygen possibly present in bulk CO2. Courtois says the recaptured CO2 from the Earthly Labs system shows single-digit O2 levels—a difference that “allows the brewer’s vision to shine with better head retention, better lacing, and a cleaner, more vivid aroma.”


Photos: Courtesy Roadhouse Brewing

A Matter of Scale

In speaking to more than a half-dozen brewers using the Earthly Labs systems or looking to add carbon-capture capabilities, the closest thing I hear to criticism of the system—beyond comments about the six-figure up-front cost—is when Kevin Brand, owner and founder of (512) Brewing in Austin, says, “I wish we could use it more.”


He says the system works best when connected to an active fermentation in one of the brewery’s 120-barrel fermentors, though 30-barrel and larger vessels also are compatible with the CiCi. “The most exciting part isn’t the money we’re saving, but the feeling we get when we’re running the system,” Brand says.

Brand was an early adopter of the CiCi in Austin, and he worked closely with Earthly Labs to iron out wrinkles in the first implementations. The CiCi’s current iteration, known as the Oak, works best at breweries that produce between 5,000 and 20,000 barrels annually.

Amy George, founder and CEO of Earthly Labs, calls it a “one-size-fits-most solution,” adding that the company is developing both smaller and larger units. Meanwhile, demand for the units is surging—along with the lead times.

Beyond the initial cost of the system, there’s a nominal operating cost as the carbon-filter medium needs to be changed regularly. (Earthly Labs includes a year of replacement medium in the up-front cost.) The compressor uses some power; George estimates that the energy required costs less than $1,500 per year. “I didn’t notice a change in our electric bill,” says Brand at (512).

Other benefits are less obvious at first glance.


At Colorado’s Denver Beer Company, the CiCi wasn’t a perfect replacement for bulk CO2, but there was enough value in the recaptured CO2 to make the system attractive.

Denver Beer produces about 25,000 barrels a year—on the high end of what the current CiCi model can handle. The brewery still uses a bulk tank to carbonate its beer. Instead of carbonating, the recaptured CO2 pushes beer through the draft systems in the brewery’s three taprooms, replacing the costly CO2 deliveries at the retail outlets. More significantly, they sell any excess recaptured CO2 to a Denver-area cannabis-growing operation.

“We’re super-happy to have the CiCi,” says Denver Beer founder Patrick Crawford. “It’s a great marketing tool.”

Of course, the initial capital outlay is nothing to sneeze at. In much of the country, CO2 still costs less than 25 cents a pound, and that could push the return-on-investment past four or five years. However, many Earthly Labs’ clients have used creative financing agreements, partnerships, or government grants to soften that blow. Those clients also say that using the CO2 from their own fermentations is a value-add greater than the line item on the balance sheet.

One obvious barrier is that not many breweries can use this tech yet. Earthly Labs’ current offering is meant for breweries of a certain size. Bart Watson, chief economist at the Brewers Association, says that only 4 or 5 percent of the country’s breweries are in that range of 5,000 to 20,000 barrels a year.

However, the smaller units in development will unlock a larger chunk of the market. If the technology eventually proves cost-effective for most breweries, the days of bubbling blow-off buckets could be numbered.