Cream chargers are filled with Nitrous Oxide gas because this migrates easily into the cream, and does not cause the cream to oxidize while it is in the whipper dispenser. The cream must have a minimum fat content of 28% to produce whipped cream. To use a whipped cream dispenser, one starts by following a recipe — typically 1 cup of heavy cream, 2-3 tablespoons of sugar, and any flavourings/colourings as desired. The device is capped and one or two cream chargers are discharged into the unit, depending on its size. Whipped cream chargers are designed to be opened with a device that punctures the thin metal seal at the narrow end of the tube, whipped cream dispensers have this integrated into the device's cap. These pressurize the device with nitrous oxide and cause the fat-soluble gas to dissolve into the cream, just like carbon dioxide dissolves into water to create soda water. Shaking the dispenser a few times helps the gas dissolve. The dispenser is then ready for use.
When the cream dispenser's valve is opened, the cream is forced out of the nozzle by the high pressure. However, when the pressure is released, the dissolved gas turns to bubbles and comes out of the solution — just like how opening a soda bottle results in the formation of a head of bubbles. These expanding bubbles instantly transform the cream into a frothy, whipped state. Nitrous oxide is bacteriostatic (prevents bacteria from growing) and a charged cream dispenser can be kept in the refrigerator for up to 2 weeks.
In Europe, where production and use of whip cream chargers originated, there are presently 3 factories in production. The standard size for whip cream chargers is 8 grams of nitrous oxide per cartridge. European name brand chargers are considered to be the best quality N2O whip cream chargers, due to their strictly controlled manufacturing procedures and repeated cleanings during manufacture (to prevent toxic machining oils from remaining in the charger). Recently some production has begun in China however the quality aspect is not proven. The European Community has very strict and enforceable laws for production of consumable goods.
Whipped cream chargers are intended for low-volume or occasional use, such as home kitchens, restaurants, and coffee shop applications. For very high volume commercial use, there exist regulated tank systems for filling much larger containers and dispensing more whipped cream. These are more desirable if the volume is in excess of a production level of 10 litres per hour.
You can purchase cream chargers and whipped cream dispensers from www.creamchargersuk.co.uk for the best prices online.