Originally Posted by herman2011
Is beer gas (75% nitro, 25% CO2) necessary if I force-carb ahead of time with 100% CO2? The reason I ask is:
[*]I can get refills with 100% nitro much cheaper than a beer-gas mix[*]I am wondering if I keep the pressure at 30PSI (a typical level for pouring with nitro through stout faucets) if over time, the 25% CO2 in the beer-gas mixture will start to carbonate my beer beyond my original desired level.
You can use 100% nitro (or argon) as others here have done, but you'll slowly lose carbonation as the keg empties. The question is whether or not the savings are worth the slight decline in carbonation. Some claim that the decline in carbonation is pretty small, but I have no firsthand experience myself.
If using beergas, you'll want to set the pressure so that it maintains your desired carb level (just like you do with 100% CO2). This is usually between 30 and 40 psi for most people, but it may need to be higher or lower depending on your serving temp, desired carb level, and which beer gas blend you're using (70/30 and 60/40 are other common ones). Using the 75/25 blend and 30 psi you mentioned would typically be for beers in the 1.2-1.3 vol range.
Here's a calculator that you can use to determine the proper pressure using a given gas blend-http://mcdantim.mobi/easypsig
Originally Posted by krenshaw
can you put it in simpler terms? i was thinking about getting a beer gas setup for my keezer i'm building.. what is the recommended way of serving/storing something with that.. force carb with co2, then once carbed replace the headspace with 30psi beer gas and keep it that way? how long would that keep good w/o losing carbonation?
You can prime to carb naturally, force carb with 100% CO2, or force carb with beer gas, but using beer gas takes longer and is more expensive, so it's not usually recommended. The beer gas is designed to maintain a low carbonation level while using the much higher pressure needed to make use of the restrictor plate in a stout/nitro faucet. If properly balanced, it won't change the carbonation level at all.