How Much CO₂ Is In Beer?

If you’ve ever stared at a freshly poured pint and watched the bubbles race to the top, you’ve witnessed some surprisingly complex physics in action. A 2021 study published in ACS Omega by researchers at the Université de Reims Champagne-Ardenne set out to answer a deceptively simple question: how many CO₂ bubbles actually form in a glass of beer?

The answer turns out to depend on a delicate interplay between dissolved carbon dioxide, the temperature of the beer, tiny imperfections in the glass, and even the shape of the glass itself. The researchers found that a standard 250 mL lager served at 6°C holds roughly 5.5 grams per liter of dissolved CO₂ — about half the concentration found in champagne. Once the cap comes off and the beer hits the glass, almost all of that dissolved CO₂ needs to escape, and it does so through thousands of bubbles nucleating from microscopic crevices and cellulose fibers on the glass surface. Those bubbles grow as they rise, picking up more CO₂ from the surrounding liquid on their way to the top.

Natural Carbonation vs. Forced Carbonation

This brings us to how that CO₂ gets into the beer in the first place. There are two fundamental methods: natural carbonation and forced carbonation.

With natural carbonation, a small amount of priming sugar is added after primary fermentation is complete. The beer is sealed — in a bottle, keg, or tank — and residual yeast ferments that sugar, producing CO₂ that has nowhere to go but into the beer itself. This process takes an additional two to four weeks and produces fine, tightly integrated bubbles. Many brewers and beer enthusiasts report that naturally carbonated beer has a smoother, creamier mouthfeel with smaller bubbles and better head retention.

Forced carbonation takes the shortcut. The beer is chilled in a keg and pressurized CO₂ gas is pumped in from an external source — typically a cylinder or bulk tank. Over a few days the gas dissolves into the beer. It’s faster, more predictable, and gives brewers precise control over carbonation levels. For bars and restaurants that serve beer on draft, forced carbonation and CO₂-pressurized draft systems are the standard. CO₂ doesn’t just carbonate the beer — it’s what pushes it through the lines and out of the tap.

The Hidden Cost: Wasted CO₂

Here’s where things get expensive. In traditional bulk CO₂ systems, the gas is stored at high pressure and must be periodically vented to maintain safe operating conditions. That vented CO₂ is simply released into the atmosphere — gas you paid for that never touched a single pint. Industry estimates suggest that conventional venting bulk systems can waste a significant percentage of the CO₂ a bar or restaurant purchases. On top of that, venting increases the concentration of CO₂ in enclosed spaces, which creates ventilation concerns and potential safety hazards for staff.

For a busy bar or restaurant pouring hundreds of pints a day, that wasted gas adds up fast — both in direct CO₂ costs and in the lost revenue from beer that could have been poured.

How WestAir’s Eco-CO₂ System Solves the Problem

This is exactly the problem WestAir’s Eco-CO₂ system was designed to fix. Unlike traditional bulk CO₂ setups, the Eco-CO₂ system uses a patented diverter valve and stationary cylinder bank that eliminates venting entirely. That means 100% of the CO₂ you pay for goes into your draft lines — not into the air.

Customers using the Eco-CO₂ system have seen up to 30% reduced CO₂ usage compared to conventional systems. The system is paired with real-time telemetry monitoring through Pulsa sensors, so WestAir can track your CO₂ levels remotely, detect leaks early, and schedule refills automatically through a convenient outdoor fill box. No cylinder swaps, no downtime, no running out mid-shift.

For a bar or restaurant owner, the math is simple: less wasted gas means lower CO₂ costs, fewer deliveries, and more revenue from every keg. And because the system doesn’t vent, it’s safer for your staff and better for the environment.

The Bottom Line

Whether your beer gets its fizz from yeast doing its thing naturally or from a pressurized CO₂ system behind the wall, one thing is clear — CO₂ is essential to every pint you pour. The science tells us that the carbonation experience your customers enjoy comes down to precise levels of dissolved gas. Wasting that gas before it ever reaches the glass doesn’t just cost you money — it undermines the quality of the pour.

If you’re a bar, restaurant, or brewery looking to cut CO₂ waste and improve your draft system, talk to WestAir about the Eco-CO₂ system. Learn more here or contact us for a free consultation.

References

1. “How Many CO₂ Bubbles in a Glass of Beer?” ABS Publications, March 31, 2021 https://pubs.acs.org/doi/full/10.1021/acsomega.1c00256

Tyler O'Brien

Tyler is a results-driven marketing professional specializing in the industrial gases and equipment industry, bringing his 10 years of technical expertise and digital marketing acumen to the complex industrial gas B2B environment.