Why can't I make a good yogurt sauce?

Whenever I try to make a yogurt sauce, the yogurt de-emulsifies and I end up with little lumpy curds and water instead of a creamy sauce. What am I doing wrong?

Jay,
Are you heating the yogurt or making a cool sauce. What yogurt are you staring with?

Yesterday I used Chobani plain “Greek” yogurt. I was trying to make a yogurt curry sauce for assorted steamed and sauteed vegetables. I put the vegetables in a cast iron pan, added assorted spices, turned on the flame and added yogurt. It de-emulsified within 10 seconds as it heated. I have also tried it with curried chicken preparations and I usually get the same result.

You need to strain the yogurt some more Jay. Colander lined with cheesecloth over a bowl in the fridge. Quite a few hours involved so plan accordingly. You can use the strained whey to add protein to shakes afterwards.

For a curry style sauce I thing I would start with toasting the curry in the pan then add some oil and maybe chopped onion. Then sauté the veggies and when finished add the yogurt off the heat.

I prefer starting with thinner yogurt (not Greek) for sauces.

Jorge’s suggestion to strain some liquid from the yogurt is a good one.
I would temper the strained yogurt with some of the hot curry stock just a few tablespoons before adding it whole hog to the vegetables.

I use the whey to make lacto fermented lemon/lime aid with ginger.

J