I've been making David Leite's milk mayonnaise as my homemade mayo for a while now, mostly because it comes together more easily for me than an egg mayo, but also because I love the brilliant white color. I noticed one time when I forgot to add the lemon juice before blending that the mixture didn't thicken up until I added some acid. The next time I had some buttermilk on hand I decided to give it a go as the base, as it is both emulsified and acidified. Lo and behold, it worked, and it makes a great base for an herbed dressing or dip. Now instead of mixing the right ratios of mayo, buttermilk, and yogurt for a ranch dip I just emulsify it all together. —prettyPeas
cloves garlic, pressed (or 4 cloves roasted)
oil, neutral (may substitute up to 1/4 cup with olive oil)
Add pressed garlic to buttermilk and blend with immersion blender.
Add oil slowly in a thin stream. Once mixture begins to emulsify it is safe to add oil more rapidly. I haven't broken this emulsion once (thought I've messed up traditional mayonnaise several times).
If mixture hasn't formed a "thick dressing" consistency after adding all the oil add a bit of lemon juice or other acid (no more than 1/2 tsp.) and blend fully. I've had different results with different buttermilks.
Salt and pepper to taste.
Chop herbs to smallish pieces which won't wind around the immersion blender.
Blend all ingredients until smooth. If mixture isn't thick enough add additional yogurt and oil and reblend.