Commercial Hardware and Techniques (part 4) - Cream Whippers - Chocolate Mousse

2. Cream Whippers (a.k.a. “iSi Whippers”)

We’re all familiar with whipped cream in a can. A cream whipper is a reusable version of the can, without the cream, that you fill with cream or whatever else you like. They’re a simple yet clever design: pour your contents into the container, screw on the lid, and pressurize using a small, bullet-like cartridge that provides either nitrous oxide or carbon dioxide to the can through a one-way valve.

Cream whippers take their name from their primary purpose: making whipped cream. With a whipper, you can control the quality of the ingredients and the amount of sugar used. Fill it up, store in the fridge, and there’s no functional difference between a whipper and the more familiar whipped cream in a can.

The obvious extension is to create flavored whipped cream. Toss some orange zest and maybe a bit of vanilla sugar into a pint of organic cream, and spray away. Try tea-infused cream: steep some Earl Gray in cream and transfer it to the whipper, or go smoky and use Lapsang Souchong. Just remember to strain the tea leaves out before filling the canister of the whipper! You can also spike the cream—make amaretto cream to go on your coffee with 4 parts heavy cream, 2 parts amaretto liqueur, and 1 part powdered sugar.

But the real fun with cream whippers (besides whipped cream fights) is passing other liquids through them. You can whip any liquid or mixture that has the ability to hold air—that is, anything that can be turned into a foam (sometimes called an espuma in menu speak), including foamed “waters” flavored like carrots or desserts like chocolate mousse. You can even put pancake batter in a cream whipper (hence the whole “pancakes in a can” thing). Because the contents are ejected under pressure, small, pressurized bubbles come along for the ride and expand, leading to mechanical injection of air into the liquid. This is why cream turns into whipped cream, although the foam that’s generated isn’t as stable as manually whisked whipped cream.

The most common brand of cream whipper used in the food industry is made by iSi (it’s not uncommon to hear a cream whipper simply called an “iSi”). Regardless of manufacturer, basic models run $40 to $60 dollars; cartridges are about $0.50 each in bulk.

Note:

Don’t use chargers made for BB guns. They aren’t food grade.

This might be more than you want to spend upfront for just whipped cream, but if you’re a regular user of the canned stuff, the long-term savings alone will make it worthwhile. If you want to play around with textures and flavors in the kitchen, it’s downright cheap.

Cream whippers also come in a “thermal” style (i.e., built like a Thermos) that’s useful for keeping contents cold if you’re working onsite. The thermal versions can’t be used in water baths, though, making it harder to do hot foams or to partially poach the contents à la sous vide for egg-based custards.

A few things to keep in mind when working with a whipper:

• Make sure the gasket is properly seated and the threads on the lid are clean when screwing on the lid, unless you want chocolate cake batter, cream, or pancake mix sprayed 10 feet in a random direction.

• Always run your liquid through a strainer (~500 micron is fine) to remove any particulates that might clog the nozzle. You can skip straining things like plain cream, of course.

• When working with heavier batters, you can double-pressurize the canister. After pressurizing with one cartridge, remove it and pressurize with a second one. You’ll find that the pressure decreases as you run through the contents, because the airspace in the whipper increases as the contents are ejected.

• If your liquids fail to foam correctly, try adding some gelatin, which provides structure. If you don’t mind taking a shortcut, try using flavored Jell-O.

You can also use a whipper as a source of pressure. One technique uses an adaptor from McMaster-Carr to connect the spray nozzle of the whipper to a length of plastic tubing. Fill the tubing with a hot liquid with agar or other gelling agent, let it set, and use the whipper to force-eject the “noodle.”

Another thing to try is using a CO₂ cartridge to create “whipper fizzy fruit”—fruit that has been carbonated, giving it a fizzy texture. Try popping grapes, strawberries, or sliced fruit such as apples and pears into the canister and pressurizing it. Let rest for an hour, depressurize, and remove fruit. Not exactly haute cuisine, but fun to do as a party trick. Fizzy raspberries make a great basis for a mixed drink.

Foamed Scrambled Eggs

This egg foam is something like a whipped mayonnaise, but incredibly light. Try it with steak and fries. 

Measure out into a bowl:

4 large (240g) eggs

5 tablespoons (75g) heavy cream

½ teaspoon (2g) salt

½ teaspoon (2g) sriracha sauce

Using an immersion blender, thoroughly purée the ingredients. Strain into a nonthermal whipper and screw lid on, but do not pressurize. Place whipper in a water bath at 158°F / 70°C and cook until the mixture is partially curdled, around 60 to 90 minutes. Remove from bath, check that eggs are just partially set, and pressurize. Dispense into small bowls and garnish, or use as a component in a dish.

Notes

Try using the small strainer from a loose-leaf teapot when filtering liquids—it’s easier to hold above the container while pouring in the mixture.