Efficient use of carbon dioxide (CO2) in brewing has become exponentially more important in recent months. CO2 scarcity and supply chain disruptions have made efficient use of CO2 not only a financial and environmental impact consideration, but potentially the difference between saleable beer and interruptions in brewery production. While brewers may have very little control over market forces that affect CO2 pricing and production volumes, they can take steps to ensure their brewery is getting the most value per pound of CO2.
As any first year MBA student will tell you with an air of moral authority “you can’t manage what you can’t measure.” Begin by determining how many pounds of CO2 your brewery uses per barrel packaged. If your brewery isn’t already using one, the Brewers Association (BA) has developed a Data Management and Benchmarking Tool for tracking utility intensity and performance. Then use the pounds of CO2 per barrel packaged to benchmark yourself against brewers of similar size (Figure 1). If you find that you are not in the top 25%, it’s possible there is still some of that sweet, delectable low hanging fruit available.
Even if your brewery is in the most efficient 25% for CO2 use, it’s likely that there is still some room for improvement. After all, per the first four years of BA benchmarking data, CO2 is only 7-18% of total utility cost per barrel for craft brewers of any size. That means the odds are it hasn’t been the primary focus of efficiency projects and that some changes deemed too costly in the past may seem attractive now.
The BA has published a thorough list of Tips for Reducing CO2 Use which also includes important safety considerations. Of the many savings opportunities, a few that are low cost and universally applicable include:
- Routine audits of your CO2 system(s): Check to see that your system is free of leaks either with a spray bottle of soapy water or an ultrasonic compressed gas inspection. The latter can often be subsidized by local utilities if it includes compressed air.
- Optimize processes that consume the most CO2:
- Tank purges are heavy users of CO2. Ensure that Standard Operating Procedures (SOPs) are written to use only the necessary quantity of CO2 and that those SOPs are followed. A purge at 5PSIG through a ½” line allowed to run for an additional 10 minutes can consume 8 pounds of CO2 or nearly a gallon of liquid CO2.
- Consider repurposing CO2 displaced when racking from fermenters to brite tanks to reduce the volume of gas used to purge subsequent tanks.
- When carbonating beer, maximize solubility of CO2 by allowing beer temperature to reach the appropriate set point and increase contact time by employing a carbonation stone.
- Compare your CO2 usage with peers and share best practices: If a peer is using less CO2 per barrel packaged it may be the nature of your process (cans consume far more CO2 then bottles) or there could be best practices to share.