Here in North Texas, I can only find ultrapasteurized milk in the supermarket -- no good for cheeses made with curds. However, I have successfully used Jersey cream (from Costco) and ultrapasteurized half and half for sour cream, cream fraise and cream cheese. Otherwise, I drive an hour into the country to a dairy for Jersey raw milk or raw goat's milk, which is expensive but works well at least for this newbie.