Whipped cream is a favourite topping for ice cream, cakes, pies, and more. But what’s the science behind that fluffy, silky texture?
The whipped cream we love is made by whipping dairy cream, which contains water, milk sugars, and fat globules. During whipping, air bubbles become trapped in the mixture, and molecules of fat rearrange themselves around them to prevent them from escaping.
Using Cream Chargers is a popular method for making whipped cream quickly and easily. Cream Chargers are small, pressurized canisters filled with nitrous oxide gas, which helps to stabilize the whipped cream and keep it from deflating too quickly. By using Cream Chargers, you can create a larger volume of whipped cream in less time, making it a popular choice for both home cooks and professional chefs alike. So whether you prefer to whip your cream by hand or with the help of Cream Chargers, there's no denying that whipped cream is a delicious and versatile topping for all kinds of sweet treats.
Air Bubbles
When you beat air bubbles into the cream using a whisk, the pressure of the whisk traps and expands the tiny air pockets to form a foam. This is a fairly well-understood physics process.
However, the gas expansion mechanism for a nitrous oxide-powered whipper is quite different. The whipped cream actually absorbs the nitrous oxide you put in it.
This is because the nitrous oxide you put in is pressurized, and so the dissolved gas expands to form air bubbles within the cream.
This creates a much more stable structure than whipped cream made with milk, which is less dense and doesn't hold up as well because of the presence of fat. Skim milk creates better bubbles than whole milk, but it still doesn't hold up as well unless combined with stabilizers.
Fat Globules
As whipped cream is whipped, air bubbles are formed and fat globules collect in the walls of those bubbles. This is because the atoms that make up those fat globules are held together by strong molecular bonds.
When the whisking stops, those atoms can no longer hold themselves together. They begin to coalesce with each other, creating a dense, lumpy mass of butterfat that destabilizes the foam.
This is why only cream with a minimum of 30%-35% fat content can be whipped into a stable foam. It is also why aerosol cans and nitrous oxide-powered dispensers do not work as well.
Instead, fat globules soften and to some degree liquify as they are warmed up, allowing them to adhere more easily to each other. This partially coalesced fat layer becomes part of the air/serum interface, and it adds viscosity to the serum phase of whipped cream.
Emulsifiers
Emulsifiers are a type of stabilizer that helps keep oil droplets dispersed throughout aqueous ingredients like water. They also help prevent the tiny droplets from coming back together and forming their own layer.
They’re also great for preventing fat bloom, which happens when there are large clumps of oil clinging to the surface. This can lead to a sticky, oily, and greasy appearance on the product.
When you add an emulsifier to oil and water, the two substances mix, creating a suspension called an emulsion. It’s important to remember that the emulsifier should be added to both the water phase and the oil phase, not just to one of them.
Unlike egg whites, oil and water cannot normally mix and separate, so a lot of emulsifiers are designed to force these two substances to mix and create a smoother, more uniform preparation. This is why they’re so popular in baking.