CO2 vs Nitrogen Quiz
CO2, pure nitrogen, or a blended gas mix? The wrong choice leads to flat beer, overcarbonation, or ruined foam. This quiz identifies the exact gas your system needs, the right equipment to use it safely, and warns you about common gas mistakes — including the beer-gas-on-regular-beer mistake that ruins kegs.
Question 1 of 5
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What You Need
Serving Settings
Gas Comparison Quick Reference
| Gas | Blend | Use For | PSI Range | Regulator Fitting |
|---|---|---|---|---|
| Pure CO2 | 100% CO2 | Standard beer — direct draw or forced-air | 10–14 PSI | CGA-320 (right-hand thread) |
| CO2/N2 Blend (Brewers Blend) | 70% CO2 / 30% N2 | Regular beer — long draw glycol systems at 15–30 PSI | 15–30 PSI | CGA-580 (left-hand thread) |
| Beer Gas (G-mix) | 25% CO2 / 75% N2 | Nitro beers ONLY (stouts, nitro IPAs) | 25–35 PSI | CGA-580 (left-hand thread) |
| Pure Nitrogen | 100% N2 | Nitro cold brew, wine preservation, still beverages | 30–50 PSI | CGA-580 (left-hand thread) |
| CO2/N2 (cold brew) | 70% N2 / 30% CO2 | Sparkling cold brew coffee | 35–45 PSI | CGA-580 (left-hand thread) |
Critical: Beer Gas on Regular Beer. Using 25/75 CO2/N2 (beer gas / G-mix) on regularly carbonated beers flattens the keg within 3–5 days. The CO2 partial pressure in beer gas is only ~6–8 PSI equivalent — far below what is needed to maintain standard beer carbonation. Only use beer gas on nitro beers with a stout faucet. — BA Draught Beer Quality Manual, Appendix C
Regulator fittings are different by design. CO2 uses CGA-320 (right-hand thread). Nitrogen and all mixed gas cylinders use CGA-580 (left-hand thread). This prevents accidentally connecting a CO2 regulator to a high-pressure nitrogen or mixed gas tank, which could be dangerous. Always verify fitting type before ordering a regulator.