When you understand the actual mechanism at work with cream whippers and the role of the nitrous oxide chargers then you will be able to appreciate exactly what is going on within each recipe and this will allow you to expand the ideas and also to notice when something is not going according to plan.
The process of using a gas whipped is simply a process of injecting gas into a liquid – in this sense, it is no different from the process of using a soda siphon. The real difference is the actual gas that you are using – a soda syphon cartridge is a pressurized canister of carbon dioxide (CO2) whereas a cream charger is a canister of Nitrous Oxide (N2O). It is the different properties of these two gasses that give them entirely different culinary purposes.
1. CO2 is more soluble in water then N2O – this is why carbonated drinks are fizzy but and product from a cream whipper is not.
2. CO2 is acidic but N2O is neutral – the acidity is what makes fizzy drinks tangy, and is why seltzer tastes considerably different to the water that it was created from. Nitrous imparts precisely no flavor to anything that it is passed through which is why it can be used for sweets, savories and drinks.
3. Nitrous can dissolve in fat when held under pressure – this is why liquids with a fat content of approx. 27% can easily be whipped using a whipped cream charger this could be fat within whipping or double cream or some recipes call for the addition of another type of fat (usually butter) So, what actually happens when you use a cream charger to prepare some food or drinks? Well the process is quite straight forwards. Whatever you intend to foam is placed into the bottle of the dispenser this is then made pressure-tight when the head is screwed down. The charger canister which contains 8 grams gas is use to pressurize the liquid and force the N2O to dissolve into it.
Depending upon the recipe this might need to be done while the contents are still warm to give the gas a chance to penetrate the substance at a molecular level. When the trigger is pulled then the contents of the dispenser will be propelled out under pressure and simultaneously the encaptured nitrous oxide will expand. All the recipes include some form of fat or a gelling/thickening agent to make sure that the gas does not simply bubble out and disappear into the atmosphere. When you understand the process above then you’ll get much more from the recipes.
A few tips: Give the contents of the wipper time for the gas to infuse, always shake the contents to ensure even gaseous distribution. Try to avoid any lumps, seeds, pips or bits in you mixture that might block the dispenser nozzle.