Evaporated milk, or condensed milk, is heated in a partial vacuum until it loses between 50 and 60 percent of its liquid. It is considerably thicker and creamier than regular milk. Producers of evaporated milk sterilize and can it after the evaporation process. You can store a can of evaporated milk in the pantry for several months. Evaporated milk has slightly sweeter taste than regular milk, as the lactose and protein begin to brown when the milk is heated. Don't confuse regular evaporated or condensed milk with sweetened condensed milk, though. A considerable amount of sugar is added to sweetened condensed milk after the evaporation process.

To make dry milk or milk powder, producers remove all of the liquid from regular milk. Regular milk is heated under pressure at a high temperature, until 90 percent of the liquid evaporates. The rest of the liquid is removed by spraying the mostly dried milk into a hot chamber, which causes the remaining liquid to evaporate. Kept at 50 degrees Fahrenheit, dry milk powder will keep for up to 48 months. Keeping the powder in a dark, dry place and limiting exposure to oxygen will also prolong its life. Typically, dry milk is fat-free, as the fat goes bad more quickly and can make it difficult to reconstitute the milk.

In a pinch, you can enjoy evaporated milk or dry milk as you would a glass of regular milk. To make a cup of milk using regular dry milk, combine 1 cup of water with 3 tablespoons milk powder. If using evaporated milk, mix together 4 ounces of evaporated milk with 4 ounces of water to get a cup of regular milk. Some recipes also call for evaporated milk or dry milk powder as an ingredient. For example, pumpkin pie recipes and certain casseroles use evaporated milk for creaminess. Dried milk powder is a common ingredient in bread recipes.

Just as you can substitute evaporated or dry milk for regular milk, you can also substitute dry milk for evaporated milk in a recipe. Use 40 percent of the water you would use to make regular milk, though. For example, if the recipe calls for 1/2 cup of evaporated milk, use 3 tablepoons of dry milk and about 3 ounces of water as a substitute. If the recipe calls for full-fat evaporated milk and you use low-fat or non-fat milk powder, there might be a slight difference in the flavor or texture of the finished recipe.