What types of mustard, aside from Dijon, can be used when making vinaigrette?
We typically add Dijon mustard to our vinaigrettes, but we decided to see how three other common varieties—whole-grain, yellow, and dry mustard powder—would compare. We made four batches of dressing using 6 cup of olive oil, 2 tablespoons of vinegar, and 1 tablespoon of each type of mustard, whisking each batch by hand for 1 minute.
Flavorwise, the dressing made with Dijon had a mellow, well-balanced bite that tasters unanimously preferred. Whole-grain mustard was a close second, with flavors that were more muted; its tamer taste was not surprising when we learned that mustard’s potent flavor is contained within these seeds, which must be ground to fully release flavor. Tasters weren’t wild about the tart, tangy flavors of yellow mustard in vinaigrette, but only the harsh, sharp taste of dry mustard powder didn’t pass muster.
But mustard is also added to dressing as an emulsifying agent that encourages oil and vinegar to stay together. The Dijon dressing held for 2 hours with no sign of separating, the batch made with the mustard powder never came together at all, and the vinaigrette made with the yellow mustard began to separate soon after we stopped whisking. The strongest emulsifier was the whole-grain mustard, which held the oil and vinegar together for a full week in the fridge. The reason for these differences? It all comes down to mucilage, a mix of proteins and polysaccharides that surrounds the mustard seed hull and is highly effective at stabilizing emulsions. Because whole-grain mustard has the most seed hulls, it contains the most mucilage and therefore builds a thicker, longer-lasting vinaigrette. Dijon mustard is made with finely ground whole seeds, which is why it works well, too.
THE BOTTOM LINE: Save the yellow mustard for hot dogs and the powdered stuff for baked beans. If you’d like a more subtle mustard flavor and a longer-lasting emulsion, go with the whole-grain stuff.