How can I prevent milk from curdling when I make cream of tomato soup or scalloped potatoes?
The protein in milk is likely to clump together when it is exposed to acid or salt, causing curdling. A number of things may help avoid this situation. For cream of tomato soup, try adding the tomato to the milk rather than the opposite, have both the milk and tomato hot, and thicken either the tomato juice or milk before they are combined. Serve the soup promptly. When making scalloped potatoes, if you avoid too high an oven temperature and too long a cooking time, the milk is less likely to curdle. Parboiling the potatoes and using evaporated milk further aids the product. When ham and scalloped potatoes are baked together, curdling will occur. Ham contains curing salts, which make the milk protein extremely unstable.
