primacoffee wrote:N2O seems like a strange choice of gas in this context. N2 is the standard. It is flavorless, it doesn't react with coffee, it is abundant and cheap. N2O has a sweet taste that will be imparted to the beverage, and while it's quite commonly available for cream whippers it's not usually used for kegs. It also generally creates a coarser foam/larger bubbles than N2. My preference would be to use N2, but I don't know if there are compatible cartridges for your device. N2 is sold in 2 gram chargers for whipping siphons, as well as some larger threaded cylinders for wine preservation systems.

GrowlerWerks wrote:N2 is what is most commonly used with the mass produced Nitro coffees as it is easier to get in larger quantities and will work if you are able to find the right size cartridges. N2O is inert (most commonly used for keeping dairy in whipped cream fresh) and will not oxidize the coffee which is why we went this direction. We have put the uKeg through a variety of scenarios and even had the Starbuck's coffee counsel do some testing over a two week period and found that there was no significant different in what they are pouring and what is poured from the uKeg Nitro. To your point the Oxygen in N2O can be an oxidizer but the temperature would have to soar up high and only then would there be issues in freshness.Regarding the volume of gas in the cartridges, you will have plenty to infuse the coffee, keep it fresh, pour it all out, and a bit to help rinse out the tubing before filling it again. I am looking for documentation regarding the third part of your question on mouthfeel and fizz, but until then I do hope that helps and if you have any other questions, please let us know.

Nitrous oxide is completely inert at room temperature, which is why its used as to store things like cream and milk for several months. We also use nitrous because it's much more dense when stored, it also infuses faster and at lower pressures than nitrogen.As for taste, the nitrous does add a little creaminess to the coffee, mostly from the areation of the coffee, similar to nitrogen. It also desaturates slower than nitrogen, which means the creaminess lasts longer instead of dissipating in a minute or two. You don't get a "fizzy" sensation because the nitrous doesn't acidify the coffee as CO2 would.

The uKeg Nitro uses one N2O cartridge per fill. This is enough to infuse the coffee with the gas as well as have enough left to dispense the full contents of the uKeg. There will also be just enough in there to rinse out your uKeg for storage.