When an acid is introduced to milk, the proteins in the milk change and become clumps of solid white masses known as curds. Once formed, the curds are rinsed in water and treated with enzymes to make them tougher, or more consistent with cheese. This stiff, curdled portion of the milk contains the healthy elements of milk such as the protein and vitamin A.

According to the Gourmet Sleuth, the closest substitutes for curds are shredded mozzarella cheese and shredded mild cheddar. You select the right substitute by the determining importance of taste or texture to your recipe. The mozzarella is a great substitute for the texture of curds, but is too mild to match the flavor. Mild cheddar cheese is softer than mozzarella, but it has a flavor that is similar to curds. Look closely at your recipe and pick the cheese that brings out the most desired qualities, be it texture or flavor.

You can make your own curd to get an exact flavor and texture match needed for your recipe. Home cooks make curd by adding lemon juice or vinegar to milk and letting the milk proteins separate from the whey. The curds are strained from the liquid and rinsed in cool water before being salted. They may be slightly softer than store-bought curds, but homemade curds are next to the real thing.

Use lemon to make curds for dessert dishes like parfaits, dessert toppings and fillings. The lemon-based curd has a better flavor when mixed with sugar for dessert dishes than do the vinegar-based curds. Use vinegar to make curds for savory dishes like the Canadian Poutine or the Midwest favorite fried curds.