After almost two and a half grueling years of shutdowns, restrictions, staff shortages, and rising prices for ingredients, some local breweries are now having to contend with yet another threat to their business models: limited supplies of carbon dioxide.

Carbon dioxide is an essential component of the crisp beer experience. CO₂ gives beer a bubbly, foamy appearance and taste. It is also important for transmitting beers through taps and canning lines.

"Warm and flat is not where it's at," said Bob Pease, the president and CEO of the Brewers Association. "It's a key ingredient."

But now because of unreliable supply chain lines and contamination at a major CO₂ facility, many small breweries are left feeling high and dry.

Night Shift Brewing, in Everett, Massachusetts, near Boston, has already announced that it will have to suspend operations and lay off personnel soon because of the CO₂ shortage.

“Last week, we learned that our CO₂ supply has been cut for the foreseeable future, possibly more than a year until we get more,” the company reported on Instagram.

"Come October 1, we won’t likely have jobs for many of this team," the post continued.

Though demand for cold, carbonated beverages like beer skyrockets during the summer, demand is not the main cause for the shortage. Contamination in the carbon dioxide facilitated in Jackson Dome, Mississippi, has also greatly affected brewing capabilities. The major energy company Denbury, which owns the rights to the Jackson Dome source, claims on its website that it controls perhaps "the only significant underground deposit of CO₂ in the United States east of the Mississippi River." So any disruption at Jackson Dome would cause disruptions in many other industries, including the beer brewing industry.

And Jackson Dome isn't the only CO₂ source with processing issues.

“Several of my brewers received a Force Majeure letter yesterday from their CO₂ supplier letting them know that their plant in Illinois just suffered a mechanical failure that will shut the plant down until mid-September,” Katie Stinchon, executive director of the Massachusetts Brewers Guild, wrote in an email. “The result is a 30% reduction in contracted volume for at least the next month, and they should expect delays.”

And according to some experts, the supply chain issues have a greater impact on microbreweries than on major corporations.

"Large brewers ... may have a technology called carbon capture at their breweries that helps insulate them from supply disruption," Pease noted.

Still, despite the added setback, Pease and other brewers remain optimistic that they will be able to withstand what Pease hopes will be a short-term shortage.

"Our members have faced a long string of challenges, and we have found ways to overcome most of them," Pease said. "We will try to help our members overcome this one."

Pease said he hopes that the carbon dioxide supply issue will be resolved within the next three months.