The cream inside your Twinkie is not the same thing as the cream inside that eclair at the fancy French bakery—we know that, because real cream goes bad after a while, and can’t sit on shelves for months. So what’s really inside that Twinkie? (And are you sure you really want to know the answer?)
To understand what’s in fake cream, you first have to learn what’s in the real stuff.
What Is In Real Cream?
We know what real cream is, in the macro sense. Take the goo that comes out of a cow’s udder and leave it sitting for a while in a cool container. Thicker goo will rise to the top. Take that thick goo and add a little salt, a little sugar, and a perhaps a little vanilla for flavor. Beat it with a whisk, until you whip tiny little air bubbles into it, making it into a foam rather than a liquid. That’s whipped cream. You can stuff it in any cake and it will taste delicious. At first.
After a while, things will change. The cream will separate again. Leave a big bowl of cream sitting long enough and a whitish puddle of water will form on the bottom while the cream on the top will become less moist and both brittle and greasy at the same time.
This happens because, when the cream was still liquid, the fat molecules in the cream were surrounded with phospholipids—molecules that had water-loving ends and fat-loving ends. These were emulsifiers, keeping the water and the fat in the cream pretty well mixed together. The phospholipids formed a barrier, with the water-loving ends pointing outwards, around the fat globules, suspending them in the water of the cream the way water droplets in a cloud are suspended in the air.
Enough whisking broke up the layers of phospholipids around the fat globules. The exposed hydrophobic sides of the phospholipids repelled water, but they did trap air, allowing the cream to puff up. Essentially, the emulsifiers were doing double duty, keeping air, water, and fat suspended in a poof. Let that poof sit long enough, and the water will settled to the bottom, the same way it does in milk. This can’t be allowed to happen while a cake is on the shelf.
If you were to leave your big batch of whipped cream out even longer, you’d notice another problem: It would start to stink.
That stink is coming from the disintegration of the many acids in your cream. Cream and acid sound incompatible, but you’ve probably heard of “fatty acids.” Inside those globules of fat are collections of fatty acids—butyric acid, heptanoic acid, tridecanoic acid—connected by glycerol, a sugar alcohol. These connected fatty acids are called triglycerides. After a while, water molecules make their way into the triglycerides, breaking them apart in a process called hydrolysis. It’s also called rancidification, because it makes the cream smell and taste rancid and disgusting. This is also not what you’re looking for when you pick up a snack cake.
What Is In Fake Cream?
So what we need, in order to make shelf-stable cream, are ingredients that will replace those two perishable parts of cream. We need fats that won’t go rancid, even after they’ve been sitting at room temperature for weeks. And we need to get those fats whipped up into a cloud of air, water, and fat, that won’t separate out even if it isn’t continually being shaken up.
The fat part is easy. Rancidification happens fast to the fatty acids in cream, but it doesn’t happen to all fat. That bottle of olive oil, which has been sitting on your shelf for months, hasn’t gone rancid yet. Any of the fat sitting out in your kitchen could be made into fake cream. The vegetable oil, the soybean oil, the big tub of shortening at the back of your pantry that you only dig out once a year to make pie crust. Any fat that won’t go off can get blended with sugar and flavoring into a kind of creamlike flavor.
It’s the ability to emulsify it with water, and keep it emulsified, that makes this process difficult. There are all kinds of things that can be used as emulsifiers, but the most effective, and common, is what emerges when you mix sorbitol with stearic acid.
Sorbitol is a sugar alcohol. Sugar alcohols are slightly-tweaked sugar molecules that can’t be digested either by the human body or bacteria. They’re added to diabetic candy, but you’re more likely to find sorbitol in toothpaste or cough medicines—any product which could use a little sweetening, but in which it would be counterproductive to use real sugar. Stearic acid is a fatty acid which is often harvested from oils during the soap-making process, and which often ends up back in soap again as a hardening agent. The two of them, together, make polysorbate 60.
You have definitely consumed polysorbate 60. It’s in the coating of your chocolate-covered-coffee-beans. It’s in your hand lotion. It’s in cosmetics. It’s also in regular, full-fat ice cream. Anything that needs a smoothness and creaminess, despite containing those old enemies, oil and water, will likely contain polysorbate 60. Polysorbate 60, on its own, looks like a yellow oil—but put it into an environment with water and fat, and it acts like the phospholipids. It grabs hold of water, fats, and any air that gets whipped into the mix.
The difference is, polysorbate 60 isn’t fragile. It will keep your fake cream moist, by retaining the water. It will keep your fake cream smooth, by never letting go of the fat molecules. And it will keep the entire thing fluffy, by never letting its air bubbles pop and its air slip away. This is the permanent version of the temporary set-up that real cream has—and it can stay on the shelf for a long, long time.
[Source: Twinkie, Deconstructed by Steve Ettlinger]