by Gregory Stone '22
Whipped cream is the stuff of dreams. Light and sweet, it’s a classic topping on cakes, ice cream, fruit, and more. But what is it that gives whipped cream its unique properties?
To examine whipped cream, we must first look at its component, milk. Milk is a type of mixture known as an emulsion: small droplets of one substance dispersed throughout a liquid. In this case, tiny globules of milk fat are suspended in a solution of water and other substances like lactose.
The fat won’t dissolve in the water: fat is a non-polar molecule, while water is polar (it has negative and positive ends). So, given time, the less dense fat globules will float to the top and form a layer. This layer is called cream.
The globules of fat, mostly triglycerides, are surrounded by thin membranes made of proteins and molecules called phospholipids. The membranes keep the globules separate from each other.
A milk fat globule and its protein/phospholipid membrane
Skim the cream off the top of the container to whip. Cream can be anywhere from 20 to 40 percent fat, and more fat is better when it comes to making whipped cream. Left in the container is low-in-fat skim milk.
When you whip the cream with a whisk, you integrate air into it. You also start to break the globule membranes, allowing the globules to begin to merge. This is called partial coalescence.
The free triglycerides then spread around the air bubbles, stabilizing them. You’ve made whipped cream: a structure of fat supporting pockets of air, with water trapped in between pockets.
The structure of whipped cream
This structure is what gives whipped cream its foamy, smooth, but not greasy texture. Once it’s reached this stage, put it on your food of choice and enjoy!
What other factors affect whipped cream?
Fat content: Fattier cream whips bigger and better because more fat can support more air. Heavy whipping cream is 36% milk fat.
Temperature: High temperatures cause the fat to melt and the whipped cream to collapse. Whipped cream is best chilled.
Additives: It’s sugar that gives whipped cream its sweet taste. The sugar does make it harder to whip, but the flavor makes up for it.
Whipping time: If you whip the cream too long, all the air will get beat out and the fat globules will fully coalesce, forming butter.
Hand-whipped cream is generally considered better than the canned stuff, so get whipping!
Sources:
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