We expect a lot from oil and vinegar dressings—or vinaigrettes as they're also called. Even the simplest one is asked to do nothing less than defy the laws of nature.
That's because oil and vinegar don't naturally mix. No doubt you've seen this yourself—shake up a bottle of salad dressing and the two parts come together. Set the bottle down and in seconds, they start to separate again until all the oil is at the top and all the vinegar is at the bottom.
The best we can do is encourage them to come together for a little while, which they begrudgingly do, provided we shake, stir, or otherwise mix them up really well.
We call that a temporary emulsion—temporary because the oil and vinegar begin to separate as soon as you stop mixing or stirring. Here are a few tips and tricks to help your vinaigrettes turn out perfectly every time.
Basic Vinaigrette Formula
If you remember nothing else about vinaigrettes, remember this: the magic ratio of oil to vinegar is 3 to 1. As long as you know that, you won't need to consult a vinaigrette recipe ever again.
Different kinds of vinegar have different strengths, so the 3:1 ratio might need to be adjusted depending on taste. There are certain times when you'll want a tangier dressing and others when a mild one will do. For the most part, though, the 3:1 ratio represents the vinaigrette sweet spot.
The best way to test the flavor of your vinaigrette is to dip a piece of lettuce into it, shake off the excess, and then take a bite. This will give you a better sense of how your salad will taste than by tasting the vinaigrette "straight."
Generally speaking, any oils labeled "vegetable oil" or "salad oil" are fine for making a basic vinaigrette. You could also use any light, neutral-flavored oil like safflower, canola, or soybean oil. One of the most common variations is to substitute olive oil for salad oil. If you do this, make sure you use extra virgin olive oil, not the cheaper "light" varieties. When you consider the wide range of flavored oils that are available today, including such distinctive oils as walnut or avocado, the possible variations on the basic vinaigrette formula are literally endless.
The flavors and types of specialty vinegars—like balsamic, sherry or raspberry—are as varied and diverse as can be. Cider vinegar is made from apples and is a good choice for fruity vinaigrettes. Balsamic vinegar—sweet, dark, and aged in specially treated wooden casks—is one of the most sublime kinds of vinegar you can find. Another interesting choice, especially for Asian-flavored vinaigrettes, is rice vinegar, which is made from fermented rice. The most neutral flavored vinegar is white vinegar, but we wouldn't usually use this in a vinaigrette. If that's the only one available, at least go for a white wine vinegar.
Lemon juice is a nice component to add to vinaigrettes. It's usually used to complement and enhance the vinegar, rather than replacing it altogether (although a simple dressing of olive oil and lemon juice drizzled over a fresh summer salad is hard to beat).
All kinds of juices can go into vinaigrettes, not just lemon, though citrus fruits such as lemon, lime, and orange are used most commonly because of their high acid content. Each citrus fruit has its own unique flavor profile—orange juice, for example, adds sweetness in addition to tartness—but the overall vinaigrette formula remains the same.
A simple vinaigrette doesn't need more seasoning than a bit of Kosher salt and ground white pepper. Minced garlic, onion, shallot, and herbs are often part of the mix, along with spices such as black pepper, celery seed, paprika, and so on. Other ingredients, such as mustard or Worcestershire sauce, are common as well.
Honey happens to be a great addition to a vinaigrette as it adds sweetness, which is nice to counterbalance the tartness from vinegar or citrus. It also helps stabilize the emulsion. A vinaigrette with honey in it will remain emulsified for a longer time. Honey vinaigrettes are great for presentations where you don't want the oil and vinegar separating all over the plate.
The most effective way of combining the oil and the vinegar is in a blender. If you don't have a blender, you can combine everything in a glass or stainless steel bowl and just whisk them together thoroughly. Just don't use an aluminum bowl—the acid in the vinegar can react with the aluminum, producing a metallic flavor. You can even seal the ingredients in a clean glass jar or bottle and shake to combine.
For best results, all your ingredients should be at room temperature when you begin. The cooler the oil, the more difficult it is to make an emulsion.
Once you've mixed things up, it's nice to let the flavors meld for a while, especially when you go beyond the basic formula and introduce additional ingredients like minced onion, garlic, herbs, and so on. Ideally, then, you'd prepare the vinaigrette in advance and then let it sit for anywhere from 1 to 3 hours. Just don't refrigerate it during this time!