How to Stop Your Homemade Salad Dressing from Separating
Once you learn the secrets necessary to create an emulsified dressing, you'll never go back to the old way.
If you have ever whisked up a vinaigrette, poured it into a cruet, then watched as your dressing separated, leaving your guests to pour either all oil or all vinegar on their salads, you know the pain of a salad dressing that just won't combine. I have the solution.
I'm talking about emulsification, and it's the magical key to making high-quality dressings that stay mixed for days — yes, days — in the refrigerator. All you need is a food processor, blender, or, in a pinch, stick blender, or basic hand whisk.
How Salad Dressing Works
When you look at a bottle of perfectly smooth, perfectly blended vinaigrette, you are looking at the results of emulsification. Technically, vinaigrette is a "water-in-oil" emulsification (vinegar, a "weak acid," is typically 95 percent water). Oil and water naturally separate, but we want them to mix and stay that way. Clever chefs have figured out a way to make it happen.
In an emulsified mixture, the water-based base has microscopic droplets of oil suspended in it, and if you do it right, they will stay in suspension long enough to get through dinner.
Get the Recipe: Fresh Raspberry Balsamic Vinaigrette
The key to success lies in making your water base with some emulsifying ingredients, so it will trap and hold the oil droplets. Then, you have to add the oil in a slow, steady stream as you whisk or process it, so the stream of oil is broken into tiny droplets as soon as it enters the mix.
A Template for Dressings That Don't Separate
In this easy method, garlic and mustard are the primary emulisifiers. They act in a way that helps bind the surfaces of the water and oil parts of the dressing. Adding nuts also helps emulsify the dressing, if you choose to do that.
Build Your Base
The easiest way to achieve a fully emulsified vinaigrette is in the food processor.
With the machine running, drop in a garlic clove, maybe a small peeled shallot, or a slice of onion. Add a few tablespoons of parsley or a pinch of fresh thyme, salt and pepper, a pinch of sugar or a drizzle of honey, and a spoonful of Dijon mustard. Process.
If you want to add a couple of tablespoons of pecans or walnuts, that will make a nice, thick dressing.
Once the base is relatively smooth, drizzle in vinegar or lemon with the machine running. Scrape it all down, then put the lid back on, and turn on the machine. Drizzle the oil in slowly, with the machine running, until it is all mixed in.
I suggest going with 1/4 cup vinegar and 1/2 cup oil to make 3/4 cup dressing, and that can be doubled or tripled. You can use more oil, too, up to 1 cup, for a milder dressing.
When you take the lid off the processor bowl, you should have a well-mixed, emulsified dressing that will stay mixed for at least a day or two in the refrigerator.
How to Emulsify With a Blender
In a blender, add the vinegar or lemon first, then add the garlic, shallots, etc., and blend until smooth. Then, take the plug out of the lid and run the machine on a lower speed as you drizzle the oil in through the lid.
How to Emulsify With an Immersion Blender
Use a large cup, and follow the process for the blender. When you drizzle in the oil, tilt the cup so it can go directly into the spinning blades. (You may need a third hand to hold the cup.)
How to Emulsify With a Whisk
To use a whisk, mince all the ingredients. Place them in a medium bowl, and whisk in the vinegar or lemon. Whisking briskly, pour the oil into the tines of the whisk very slowly. You'll get a nice arm workout, but your dressing won't separate for a few hours.
Can You Emulsify With a Jar?
If you're wondering about the old-fashioned "shaking it in a jar" method, it'll only create a durable emulsification if you use a very thick base and shake like crazy to break the oil into microdroplets.
Get the Recipe: Italian Dressing Mix
Once You Master the Method, Switch up the Flavors
Your base can be changed to give your dressing a different flavor. For an Asian-inspired dressing, use rice vinegar, a shot of soy sauce, cilantro instead of parsley, and a slice of fresh ginger. Blend in a neutral oil like canola or avocado. For a Spanish flair, use sherry vinegar, season with paprika. For Tex-Mex, use lime juice, add a pinch of chile powder, cilantro instead of parsley, and a neutral oil.
You'll enjoy your salads more, with dressings that don't separate.