Many people use buttermilk powder to make their own ranch seasoning mix, which they then use to make their own ranch dressing. This is perfectly reasonable — aspirational, even! — but ranch isn’t the only salad dressing that benefits from a bit of dehydrated dairy.
Adding buttermilk powder to a simple vinaigrette gives it body, makes it taste creamier, and adds a rounded, lactic tanginess that plays a little differently than the flavour you get from acetic acid (the acid in vinegar) or citrus juice.
You can add powdered buttermilk to any vinaigrette recipe, but there are some flavour profiles it melds with a little more easily than others. It works great in a maple-dijon situation, but might not get along so well with a soy ginger dressing, so try it out with a few different recipes. The procedure for making your vinaigrettes a little creamier and a little dreamier is simple: Assemble your dressing ingredients like you usually would — ideally in a jar — then add the powder, a teaspoon at a time, shaking the jar to incorporate it into the dressing and tasting after each addition.
I made a simple dressing using this template, with 1/4 cup olive oil, 1/4 cup apple cider vinegar, a tablespoon each of maple syrup and dijon mustard, and a bit of salt. I shook all that up in a mason jar, then added the powdered buttermilk (shaking in between additions) until it reached the level of creaminess I was looking for, which ended up taking a whole tablespoon. The dressing still had the punchy flavour I look for in a vinaigrette, but it was just a little more substantial, richer, and rounded. It worked particularly well on the steak salad I had for dinner (made with some leftover board-sauced steak, naturally).