to bake flan or custard. I use cream of tartar. This is from book "Home Comforts" by Cheryl Mendelson. "Fill pot with water and add 2 tablespoons of cream of tartar or one-half cup of white vinegar per quart of water. Bring the solution to a boil; then let it simmer for ten minutes. Wash and dry as usual."
I hope this works for you.