Whipping siphons are useful for making so much more than whipped cream. We use ours all the time for making fresh soda, speeding up marinating, infusing fruit, or topping a dish with foam or flavor or textural contrast.
The siphon requires cartridges of gas, also called chargers, to pressurize the chamber holding the liquid. Carbon dioxide is best used for carbonation only. We use nitrous oxide for foaming, marinating, and infusing.
Whipping siphons were designed for aerating creams high in fat. Nitrous oxide dissolves much better in fat than in water, so high-fat liquids generally foam better in a siphon than low-fat ones do. You can, however, foam any liquid thick enough to hold bubbles. Add starch, gelatin, eggs, or agar to thin liquids to give them enough body for foaming.
Each cartridge holds 8 g of gas, can be used only once, and costs about 50 cents. Two cartridges are typically sufficient to charge a 1 L siphon. Use about 2% gas, or 8 g of gas for every 400 g of liquidmore if the liquid is low in fat.
If the seal on your whipping siphon is faulty, the gas will go in and then immediately start to leak. So listen closely as you charge it. You should hear gas filling the chamberand then silence. Still hear hissing? Remnants of a previous foam might be causing a leak, or some part of the siphon could be damaged. Vent the siphon, remove the nozzle, unscrew the top, and take out the cartridge. Then clean these parts and the rubber gaskets thoroughly, and check to make sure that they are undamaged and properly seated.
All of these parts work in conjunction. In the diagram below, we have detailed each part and its role. Whipping siphons have several uses, but we have selected foaming for the purpose of this diagram.
- The rubber gasket keeps the dissolved gas from escaping. Make sure its intact and fits snugly along the top of the lid.
- The “empty” part of the siphon is filled with gas, which pushes on the liquid and forces it through the valves.
- Charging the siphonthat is, installing the gas cartridge so that it is pierced by the pinincreases the pressure inside the canister dramatically and forces the nitrous oxide to dissolve into the liquid. Shaking the container is crucial to ensure that the gas is evenly distributed.
- Hold the siphon upside down to help the gas propel the liquid from the siphon.
- The nozzle directs the flow.
- A rapid drop in pressure as the liquid leaves the vale causes most of the dissolved gas to emerge from the solution, thereby creating bubbles that expand into foam.
- A precision valve meters the forceful flow of liquid from the siphon.
- A disposable cartridge holds 8 g of nitrous oxide. The number of cartridges needed depends on the volume of the siphon, how full the siphon is, the fat content of the liquid to be whipped, and the temperature of that liquid. Generally two cartrdiges are enough for a 1 L siphon.
Adapted from Modernist Cuisine at Home