The Importance of Stirring

Picture this. You're making dinner for your entire family. A fancy crown of pork, a huge bowl of mashed potatoes, and *insert your favorite dessert here*. Oh and a salad because serving a vegetable is mandatory. All of the ingredients for the dressing are put in a bowl: a drizzle of red wine vinegar, a smidgen of olive oil, some sugar, a dash of salt, done. You hastily whisk it all together until all of the ingredients combine...sort of. It is oil and vinegar after all, it's not like there is much you can do to combine them better. And while the salad is certainly tasty, you wish that you could have made your salad a little more special to match the rest of the meal. Some of the lettuce tastes vinegary, while other parts are oily. Is there no way to get a better mixture??? Aha! There is a better way! What you are looking for is called an emulsion.

Oil and Water DO mix....in an emulsion

An emulsion is when you combine two liquids that would otherwise separate due to density or polarity. They can be as simple as your whisked salad dressing, or as complicated as Mountain Dew (which is technically called a nano emulsion). Emulsions are all about how small the droplets of the two liquids are. A good emulsion means that the droplets are so small that they are indistinguishable by the human eye. Emulsifying involves two different parts: how you stir the liquids, and what you add too the liquids. Let's start with stirring.

There are lots of different ways to combine two liquids. You could just use a fork. Or a whisk, for a better emulsion. But think outside the box for a moment. How could we mix them further? How about a handheld milk foamer? (Which is basically just a tiny whisk that spins very quickly from a motor). Or beyond that, there is the handheld blender. These are the tools that are most available to the home cook. Past even those, scientists use machines called Rotor Stator Homogenizers, which create amazing emulsions. How we stir our liquids is half the battle, the other half is whether we use an emulsifier.

Emulsifiers, a kind of surfactant, are compounds that allow normally immiscible liquids to combine. They usually do this by binding to the outside of the droplets, making it harder for them to separate. One such ingredient is called Soy Lecithin. It is most commonly used as a dietary supplement derived from soybeans, but also has emulsifying properties. The convenient part for us chefs is that Soy
Lecithin is available at many health food suppliers or organic grocery stores.

I can see what you're thinking again. "I don't have a Rotor Stator Homogenizer! How can I create a better salad dressing from all this?" The answer is simple, and uses a device that most household kitchens contain. This might seem rather strange, but bear with me for a moment.

Put your salad dressing in the blender.

I'm serious! Think about what a blender does, it mixes all the liquids and solids at a high speed with a blade. That same principle behind making a milkshake can drastically improve your salad dressing. Still don't believe me? To prove my point, I did a little experiment involving oil and water to show you how much of a difference emulsions can make.

Now, watching that video would make you think that the whisk worked just as well as the hand blender. They all looked the same at the end. However, time shows which is truly the better emulsion. After I mixed all three solutions, I took pictures of the three cups every 15 minutes to watch their separation. Remember, the green is the whisk, the yellow is just the blender, and the blue has the emulsifier.

Notice how the green separates out immediately? The yellow separates into two layers, but clearly not as quickly or distinctly as the green. Meanwhile the blue only has a tiny strip of separation at the top. In fact, it took nearly 24 hours for the blue cup to separate into distinct layers. 

So, the moral of the story: put your salad dressing in the blender! Try it out! Leave a comment if you do and let us know how it worked for you!