Effect of the type of oil on a vinaigrette's texture?

Question

When I prepare vinaigrette, I always use the same basic technique: first the vinegar (or another acid liquid like lemon juice), some salt, a spoonful of Dijon mustard and then I add oil little by little (not as carefully as with mayonnaise – in that case I use an electric whisk – but not all at once), whisking or even simply mixing it with a spoon or fork.

Usually, that's enough to obtain a nice emulsion but in some cases the oil and vinegar never seem to mix properly and the texture isn't right. It's merely anecdotal but I have the feeling that the type of oil I use is the key factor here. Olive, walnut or pumpkin seed oil all seem to work very well, sunflower oil not so much.

My question is: Is it really the case? Does the type of oil have a well documented effect on how easy it is to get a good emulsion? And if that's the case, is there some “neutral” oil I could use instead of sunflower oil if I want to avoid the strong flavour of olive or walnut oil?

Answer 1

Add egg yolk or lecithin to your mixture and whisk it again.

Here is some theory:

To make an emulsion (consistent, not separating oil–water mixture), we rely on emulsifiers – long organic molecules that on one end bind with water, and another with oil. They play role of a glue that does not let molecules of water and oil separate.

The most common emulsifier is a lecithin – compound found in egg yolks. There is a more complete list of them I found on this website:

Emulsifiers in food

Answer 2

Yeah, sure!

Vegetable or canola (a.k.a. rapeseed) oil is used in dressings all the time! If you're having trouble getting the dressing to come together, I recommend tossing in an egg yolk to help the emulsification along.

If a raw egg yolk freaks you out you can add a teaspoon of mayo to every 3 tablespoons of oil.

If someone has an egg allergy, replace the mayo with mustard (Dijon works best, IMO).

The standard ratios I use are 1 tablespoon of acid (vinegar) to every 3 tablespoons of oil. I don't worry about slowly adding the oil it, because a brisk whisking with enough emulsifying agent always gets the result I'm looking for.

To actually answer your question: I've never noticed a textural difference in my dressings based on the kind of oil I use. HOWEVER, it's possible that how much whisking you're performing is altering the mouthfeel by pumping different amounts of air into the dressing.

Answer 3

Its the ingredients in the premixed mustard which is promoting the emulsification of the oil; have you changed the brand of Mustard you use? Try increasing the amount you use, or as already suggested use some egg yoke.