Argentum Vulpes wins the round, including the extra special bonus points for mentioning a derivative of the word "emulsion."
Have you ever wondered what soap does? Yes, of course it helps clean things, but why soap? Why not some other substance? If you want to clean something, why not just rub walrus poo all over the surface? What is it in particular about soap that makes it more effective? Answer: Soap is an emulsifier.
There's an old saying that some say, "oil and water don't mix." Or do they? Well they sort can mix quite well if they are in an emulsion.
When you add soap to oil, the soap forms microscopic bubbles which encapsulate the oil. The soap, forming microscopic shells around the microscopic droplets of oil, is "soluble," so to speak, in water. Thus all of that can get rinsed away, something that wouldn't have happened without the soap. But "soap" isn't the only game in town. You wouldn't want to eat soap of course, but there are alternatives.
Many emulsifiers are edible and tasty.
But before I go into specific examples, emulsions have something in common. Think of "suds" and "bubbles" that go with soap. The size of the "bubbles" can vary from sub-microscopic up to the obviously macroscopic. All emulsions have that this sort of thing in common: some sort of bubbly thing going on that requires an emulsifier of some sort.
Here are some food examples of emulsions:
- Mayonnaise (this is my favorite emulsion. More on this later.)
- Mayonnaise based things such as
- Tartar sauce (yummy)
- Ranch dressing (So good. Don't get me started.)
- Thousand island dressing (Wonderful on a Ruben sandwich)
- etc.
- Hollandaise (also grand. Eggs Benedict anyone?)
- Yellow mustard (Not the best emulsion example, but still awesome.)
- Most salad dressings (most, but not all. If you shake your salad dressing and it immediately separates, it's probably not an emulsion. But if you shake your salad dressing, and it stays mixed for at least a little while, it just might be an emulsion. Creamy dressings like ranch, blue cheese, are emulsions.)
- Milk (Yes, milk. Milk is a very stable emulsion [hard to break] of fats in water. But technically it is an emulsion.)
- Cream (also stable. Easier to break than milk, but still comparatively stable.)
- Whipped cream (cream is an emulsion already, so why not add a little bit of air into the emulsion too.)
- Butter (also comparatively stable.)
- Peanut butter (this is a bad example, but is technically an emulsion none-the-less).
- And as I've discovered the hard way, imitation, pasteurized, processed cheese-food spread substitute.
When the components (oil and water, or fat and water, or whatever) of an emulsion separate, the emulsion is said to "break." That means it is no longer homogenous on the macroscopic scale any more. Chefs need to be careful not to "break" their emulsions by ensuring they use the right proportions, combining ingredients the right order and using the right process.
Peanut butter isn't that great of an example of an emulsion, since once it breaks (the oil separates from the rest) it is easy to rectify just by stirring it back up, making it right again. Other food emulsions are far less forgiving. Let's work our way toward mayonnaise.
There are several foods which act as emulsifiers. Egg yoke is a good example. Egg yolk contains lecithin which is an emulsifier.
That brings us to mayonnaise.
Mayonnaise is made of
- Almost all vegetable oil: lots and lots of vegetable oil.
- A little bit of egg yolk.
- A little bit of water.
- A smaller bit of acid such as vinegar or lemon juice, just to get the PH optimal.
- Maybe some salt/seasoning for flavor, maybe.
- That's about it.
Note that all (or most) of the above are liquid. If you were to take all the ingredients, even in their correct proportions, and throw them all in a blender at once, you would
not end up with mayonnaise. Rather you would end up with a watery, oily, liquid mess.
Instead, it is necessary to pour the oil into the rest very slowly -- one drop at a time in the beginning -- while vigorously whisking.
Make you own homemade mayonnaise.
Once you have mayonnaise, you can use it to make other things such as tarter sauce or salad dressing. But when adding more ingredients to the mayonnaise, be sure to add them slowly while stirring, otherwise you can break it.
Besides soap, paint is a fine example of a non-food emulsion. When wet, the paint is water soluble making clean-up much easier. The only reason this is possible is because when "wet" the paint is much more than just wet. It's an emulsion. As part of the process of drying, the emulsion breaks leaving only the "real" paint that dries, is not water soluble, and is very difficult or impossible to clean up with only a wet sponge by that time.
Okay, Argentum Vulpes. You're up.
