There’s an irony baked into the standard operating procedures at most craft breweries: They allow a by-product of fermentation to escape unhindered into the atmosphere—but they’ll later purge tanks, carb beer, and fill cans using bulk tanks filled elsewhere with the same type of gas that was allowed to escape.
That’s a glaring inefficiency, but the real irony is that most of the retail supply of CO2 gas in America is itself a fermentation by-product from ethanol refineries.
The largest and most efficient breweries have closed that loop. They recover the gas produced during fermentation, scrub it pure, and re-use it down the line. At the craft brewer’s scale, however, the cost and efforts to recover the gas once weren’t worth the trouble. CO2 is cheap—at least, it was. The CO2 supply chain never really recovered from the pandemic and its disruptions. The market for bulk CO2 remains volatile.
After a few years of price hikes, shortages, and the all-too-common force majeure from bulk CO2 suppliers—interrupting production schedules and sending ops managers scrambling for gas—the cavalier attitude toward carbon-dioxide production in the brewery is unsustainable. Then there’s the fact that the CO2 bubbling out of the blow-off bucket is adding to the thickening blanket of carbon dioxide that creates the “greenhouse effect,” threatening our planet’s thermostasis.
Recovering CO2 from fermentation to use downstream, as practiced at high-volume breweries, isn’t new tech. A system of foam traps, filters, compressors, chillers, transient storage balloons, tanks, and vaporizers handles the capture, rectification, and storage of the recovered gas. At large scale, it’s expensive and space-intensive. However, since the critical CO2 shortages of a few years ago, the tech has been trickling down to a more craft-friendly scale.
Smaller, more accessible CO2 recapture systems are available, and a brewery no longer needs to produce 20,000 barrels a year for the numbers to pencil out on a recovery system.