A carbon dioxide shortage has driven up prices, but so far Maine breweries say they haven’t passed it onto customers, like these outside of Foundation Brewing in Portland. Shawn Patrick Ouellette/Staff Photographer

A shortage of carbon dioxide, a gas that’s integral to the brewing process, has Maine breweries adjusting their practices, absorbing price increases and wondering how long they can sustain it.

A reliable local carbon dioxide supplier and a switch to nitrogen have helped keep the problem at bay for some brewers, who say they haven’t yet had to reduce production or increase the price of their product. But that may change as the shortage persists.

“We’re told it’s expected to get worse before it gets better,” said Sean Sullivan, executive director of the Maine Brewers’ Guild. “Everybody’s in a tough spot here.”

The shortage of CO2 began in 2020 near the start of the pandemic because of a decrease in supply and has worsened in recent months because of transportation problems.

“All the major companies are in a tight spot right now for CO2,” said Will Gentry, a district manager at Maine-based chemical company Maine Oxy. “CO2 issues aren’t going to go away in the near future.”

CO2 is not harvested directly but is a byproduct of natural gas – produced, for example, when ethanol or other natural gases move along a pipeline. As Americans have decreased their use of natural gas and move toward renewable energy, there has been a resulting shortage of CO2 across the country.


“Obviously, we all want to protect the environment, but people need to understand that as we move to be more green it’s going to hurt ethanol and petroleum production, which is naturally going to hurt CO2 production,” Gentry said.

Distribution issues have compounded that, Gentry said. Maine has no CO2 processing facilities within its borders and relies on facilities across the United States and Canada. That means CO2 must be shipped in via railcars, which have been experiencing delays in recent months.

Workers can beer in the packaging bay at Foundation Brewing Co. in Portland Thursday. Shawn Patrick Ouellette/Staff Photographer

“Maine’s just not set up for CO2 success,” he said. “Those railcar systems aren’t up to date, which is hurting CO2 supply.”

The shortage has led to an increased cost for CO2, which has doubled, and at times tripled, in recent months.

“I’m worried about it. We use CO2 for everything,” said Reid Emmerich, owner of Root Wild Kombucha in Portland. “Seems odd that the thing we try to get rid of in the atmosphere is so hard to get a hold of.”

CO2 is integral to the production of brewed beverages, used for carbonation and to push beer through the brewing process, clean kegs and purge oxygen when brews are packaged.


An alternative to CO2-based carbonation is a process known as spunding, which uses a specialized valve to regulate the pressure of a fermenting tank so the CO2 produced during a yeast-based fermentation process can be recaptured. For many brewers, the longer brewing time associated with spunding and the specialized tank needed means it’s not a viable option.

“Spunding only gets us to about 70 percent of our carbonation needs,” said Christie Mahaffey, co-owner of Foundation Brewing Co. in Portland.

Christie Mahaffey, director of quality and co-owner of Foundation Brewing, stands in front of the Portland brewery’s carbon dioxide tanks. Maine, like the rest of the country, is experiencing a shortage of carbon dioxide. Shawn Patrick Ouellette/Staff Photographer

However, brewers like Mahaffey have been able to cut their carbon consumption in other areas of production by using nitrogen – a cheaper alternative to CO2 – to move the beer through the brewing process.

The shift has been a saving grace for many brewers.


“It was a no-brainer. Nitrogen is one of the most affordable and readily available gasses. It’s allowed us to be more stable with our production,” Mahaffey said.


Although the shift to nitrogen has required Foundation to buy more equipment, the cost hasn’t been a burden, she said.

Some Maine brewers have found protection from the shortage by relying on local companies like Maine Oxy to obtain their CO2. That’s the reason Paul Upham, director of operations at Portland’s Bissell Brothers Brewing Co., says he isn’t concerned.

“Maine Oxy just has a more reliable supply, they’re consistent,” Upham said.

Caitlin Flynn, tasting room assistant manager pours a beer at Foundation Brewing Company Thursday, August 11, 2022. Shawn Patrick Ouellette/Staff Photographer

Unlike other companies selling CO2, Maine Oxy has managed to stockpile the gas, which Gentry attributes to its location and partnerships with other firms in New England and Canada. Maine Oxy makes individual transportation deals with production plants across New England to distribute the product. Since the pandemic began, Gentry estimates that Maine Oxy’s business has grown 400 percent to 500 percent.

Still, brewers will have to remain vigilant as the CO2 supply shortage continues.

“A lot of folks are concerned because these challenges aren’t gonna go away,” Mahaffey said. “It’s important that people are ready to pivot and adjust.”

Only subscribers are eligible to post comments. Please subscribe or login first for digital access. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.

filed under: