Exactly How To Thicken Salad Dressings & Vinaigrettes

A thick salad dressing clings to your salad leaves.

Thin salad dressings drip off the leaves and pool at the bottom of the bowl. Yuk!

The key to a thick salad dressing is emulsifying it correctly. 

Once you’ve got the emulsifying down, you can add extras to make it even thicker.

In this article, I cover several different techniques for emulsifying and thickening your vinaigrette or salad dressing.

Ready? Let’s jump right in.

Prepare the base correctly

Failing to prepare is preparing to fail.

This applies perfectly to salad dressings!

Getting a thick and creamy vinaigrette starts with the way you make it.

Blend the dressing instead of shaking or stirring it

Oil and vinegar don’t naturally mix. 

Mix some oil and vinegar in a bowl, and the layers will stay separate. 

Vinegar on the bottom and oil on the top (just like the oil and balsamic vinegar mixture you get in fancy Italian restaurants with your free bread). 

Agitating the mixture will briefly combine the two layers (this is called emulsification), but they’ll separate again with time. 

Emulsifying a salad dressing thickens the mixture and gives it a creamy texture.

The harder you agitate your mixture, the thicker and creamier it will become and the longer the ingredients will stay together.

Shaking is the weakest type of agitation, followed by some hardcore whisking, followed by blending.

Blending the salad dressing creates a much more stable emulsion than just shaking because the blades create finer particles that can mix more effectively.

Imagine mixing granulated sugar with coffee granules. They’d be hard to separate, but you could do it.

Now imagine mixing powdered sugar with coffee powder. These would be impossible to separate!

Add the oil slowly to the vinegar

Salad dressing is a mixture of oil suspended in vinegar (or another acid).

That means it’s lots of tiny oil particles surrounded by vinegar. 

To get the thickest emulsion, you need to mix the oil slowly into the vinegar (and not the other way around!). 

Adding the oil in smaller batches makes sure the particles are as small and well mixed in as they can be, resulting in a thick and saucy dressing.

How to mix a salad dressing:

1. Mix a small amount of vinegar with the rest of your ingredients (e.g. garlic, mustard, salt, pepper). You need just enough vinegar to make sure your blender (or whisk) can pick up the ingredients.
2. Slowly drizzle in the oil, whisking or blending constantly as you go.
3. When the mixture thickens, you can add more vinegar and then continue slowly adding the oil.
4. Repeat the process until you’ve mixed all the oil and vinegar.
5. If at any point you see pools of oil forming, stop adding oil and whisk until these pools disappear.

The takeaway: go slowly and lead with the vinegar, adding the oil in as you go. 

Blending all the ingredients together at the same time can still work, but it will be hit and miss as to how stable and thick the emulsion is. The slow and steady method is much more consistent.

Use the correct ratio of ingredients

Most salad dressings call for 3-4 parts oil to 1 part acid (vinegar or lemon/lime juice), plus whatever other ingredients you’re adding.

Stick to this ratio. 

It’s been tried and tested millions of times and works.

If you add more oil than the vinegar can hold, you’re on rocky ground and risk a split, thin vinaigrette.

Add an emulsifier (e.g mustard)

Making a thick salad dressing without an emulsifier is like trying to cut steak with a butter knife. 

It’s possible, but it’s more hard work than it needs to be.

If you want a salad dressing that’s extra creamy and doesn’t separate after an hour, you need an emulsifier.

Emulsifiers bind the oil and acid, handcuffing them together so they can’t separate.

The most common emulsifier for salad dressing is mustard (normally dijon). 

Mustard is a potent emulsifier and will work without fail, which is why most salad dressing recipes already include some mustard.

If you don’t like the taste of mustard, you can take the edge off with something sweet like honey (which is a weaker emulsifier in its own right).

But, you’re not limited to mustard.

If you add too much, check this out: How To Counteract Mustard Taste

Other emulsifiers include:

• Mayonnaise 
• Tomato paste
• Honey / agave nectar / maple syrup
• Egg yolk (use pasteurized eggs for food safety) 
• Store-bought salad dressing (these contain commercial emulsifiers)
• Peanut butter / tahini
• Mashed avocado
• Soy lecithin (add in a weight ratio of 0.3% to 1.0%) 
• Miso paste
• Crushed garlic
• Silken tofu
• Aquafaba (chickpea liquid, find out how to store aquafaba here)

Some of these are stronger than others. 

For example, honey, agave nectar, and maple syrup are more of an insurance against breaking rather than an emulsifier that will stabilize your dressing for days. 

Mayonnaise and egg yolks are both powerful emulsifiers and something most people will have to hand. 

Soy lecithin is also really strong but not as universally available (FYI: some protein powders contain lecithin as an ingredient). It’s also tasteless, which is a big bonus.

Things like mashed avocado or silken tofu will provide a bit of extra thickening power just by the nature of their texture.

Related: How To Reheat Tofu

Be aware that some of these emulsifiers will shorten the life of your salad dressing (I’m looking at you, egg yolk!).

How much emulsifier do I need to use?

You don’t need much emulsifier for a salad dressing. For each tablespoon worth of vinegar you have, a teaspoon of emulsifier will do the job. But adding more won’t do any harm. Mixing emulsifiers won’t have any adverse effects either, so feel free to get creative!

Add a thickening agent (also works for non-emulsion based dressings)

I’ve talked a lot about vinaigrettes so far, but I’ve neglected dressings not based on oil and acid.

I’m going to fix that now though!

Thickening agents can help any type of dressing, no matter what ingredients you’re using.

They’ll thicken the mixture and give it a saucy consistency, while also stabilizing any emulsions that are present (however, they don’t necessarily make great emulsifiers on their own).

There are a few different options when it comes to thickeners.

• Flax / chia seeds
• Starches (corn / tapioca / arrowroot)
• Gums (xanthan / guar)
• Pureed fruit or veg
• Dairy products

Flax / chia seeds

Flax and chia seeds both gel up when you add them to liquid. 

This gelling effect thickens the liquid and makes it more gloopy.

How to use flax or chia seeds to thicken a salad dressing:

1. Mix one tablespoon of flaxseed with four tablespoons of vinegar (or water)
2. Whisk the mixture and wait 5 minutes for it to thicken.
3. Add this mixture to your salad dressing to thicken it.

The ground versions of the seeds are best to use because they’re more effective and are less noticeable in the final mixture, but whole seeds are okay in a pinch.

A bonus of using flax or chia seeds is that they’re considered superfoods, so give your salad dressing a nutritional boost.

But, for some, the gel-like texture can be off-putting.

Flax seeds have a distinct nutty taste, while chia seeds are pretty flavorless. 

Note: the body can’t digest whole flax seeds, so you only get the nutritional benefits from ground flax seeds.

Starches (corn / tapioca / arrowroot)

Cornstarch is a famous thickener, and I know what you’re thinking…

Doesn’t cornstarch only work with hot things?

And, yes, that’s true. But that doesn’t mean you can’t use it for salad dressings – it just takes an extra step.

How to use cornstarch to thicken a salad dressing:

1. Make a cornstarch slurry with a 1:1 ratio. E.g. one tablespoon cornstarch to one tablespoon liquid. 
2. Heat the mixture on a low heat in a small saucepan until it ‘blooms’ (i.e the cornstarch takes up the water, and you get a thick paste).
3. Add this paste to your vinaigrette and mix it in until the mixture thickens.

One tablespoon of cornstarch will moderately thicken one cup of liquid. Have this in mind when deciding how much to add. 

I would start slowly and add more if needed.

Cornstarch is a very effective thickener that won’t alter the texture or taste of your salad dressing. It’s also something most people have lurking around in their cupboards because it’s used in lots of recipes.

If you’re making a low-fat salad dressing and are using water or broth as part of the base, you can heat these and thicken them with cornstarch (or another starch) first, then let them cool before adding the rest of the ingredients.

Alternatives to cornstarch include tapioca starch, arrowroot powder, and potato starch. You can use all of these in the same way as cornstarch.

Gums (xanthan / guar)

Gums are popular salad dressing thickeners, and you’ll see them listed as ingredients on many commercial salad dressings.

They’re not temperature sensitive, so are fine to mix into cold dressings, and they have no taste, so won’t affect the flavors of your dressing.

Sounds too good to be true?

The one downside is that they’re SO powerful they become tricky to use.

If you add too much, your salad dressing will take on a snotty, mucus-like texture.

Disgusting, I know.

How to use xanthan or guar gum to thicken a salad dressing:

1. Make your salad dressing. It’s best to add your gum at the end.
2. Measure the weight of your salad dressing.
3. Measure out 0.1% of this weight in xanthan or guar gum.
4. Mix the gum into some oil (1 part gum to 5 parts oil). 
5. Create a vortex in your salad dressing, ideally with a blender.
6. Slowly pour the oil/gum solution into the vortex and keep blending until you’ve added all the gum.
7. Blend for an extra 20-30 seconds before assessing the thickness of the dressing.
8. Add some more xanthan/guar gum if needed.

You should only use between 0.1-0.5% of the total weight of your dressing, or in simpler terms, 1/8th of a teaspoon per cup of liquid.

If you’ve added near to 0.5% of the total weight of your salad dressing in xanthan gum, STOP and don’t add any more. Adding more will ruin the texture.

If the dressing is still too thin for your liking, try a different thickener.

Gums start swelling as soon as they hit liquid.

If you chuck the powder into the salad dressing all in one go, the gum will immediately clump, creating lots of small gel balls.

Coating the gum with oil helps stop them from working so immediately. If you don’t want to use oil, you can use some powdered sugar instead.

Blenders work best because they have high shearing capabilities, so can quickly disperse the xanthan gum. 

Add solid ingredients (fruit, veg, nuts, rice, beans, or cheese)

Pureed solid ingredients have a thick consistency and can pass this thickness onto your salad dressing.

There are so many possibilities here of what you can add. 

It’s just down to what flavors you like and how you plan to use the dressing.

Fruit and vegetables are common.

Berries, tomatoes, apples, avocado, roasted peppers, dates, shallots, onions, and garlic are all regular ingredients in salad dressings. 

Eggplants are seen less often but are easy to puree and also work as an emulsifier (as do avocados and garlic).

Another option is to soak some nuts, drain them and then blend these into your dressing. 

However, this takes some foresight. Cashew nuts work well.

Cheese like feta or parmesan will produce a creamier dressing.

For some real bulk, chuck in some cooked quinoa, rice, or beans!

One thing to note is that most of these ingredients will shorten the shelf life of your vinegarette, so this isn’t the best idea for big batches.

Add dairy

This one is probably the easiest option.

All you need to do is take a spoonful of a thick dairy product and mix it into your dressing.

Any kind of thick diary will work. 

Cream cheese, creme fraiche, sour cream, heavy cream, plain yogurt, etc.

Mixing some into your dressing will thicken the liquid but will also alter the look and flavor of the dressing significantly.

Creamy dressings aren’t a bad thing though!