Evaporated milk is canned milk and has about 60 percent of the water removed from the milk. It's also known as unsweetened condensed milk and not to be confused with sweetened condensed milk, which contains added sugar.
If you find yourself lacking the evaporated milk you need for a recipe, there are a few different substitutes you can use -- mix milk and half-and-half, use vanilla-flavored almond or soy milk instead, or stir in a thickening agent such as sugar with regular milk. You can also make your own evaporated milk.
Evaporated milk is often used in custards, pie fillings, sauces and frozen desserts. Because so much of the water has been boiled out of the milk, it's richer and creamier than regular milk so it provides a heavier, slightly caramelized-tasting concentrate for the dish that gives it a fuller body.
You can easily make your own evaporated milk in mere minutes, using only regular milk.
The resulting liquid can be used as a near perfect substitute for store-bought evaporated milk.
In order to reach a similar richness and consistency, mix 3/4 cups of milk with 1/4 cups of half-and-half. This substitute is best used when the evaporated milk's flavor would have been overwhelmed by other ingredients because the mixture won't have the same richness that evaporated milk does.
This substitute can be used if you have a dairy allergy or if you are lactose intolerant. As a substitute for evaporated milk, you can use vanilla-flavored soy milk or almond milk in its place. Just use 3/4 of however much evaporated milk the recipe calls for. However, this substitute does not work well when making a sauce because soy milk separates when exposed to high heat.
If you use regular milk on its own as an evaporated milk substitute, it will be much thinner and nowhere near as rich because regular milk contains less calories and fat. Though sometimes this isn't a big issue, if you're making a sauce you will need a way to thicken the milk to achieve the correct consistency evaporated milk would have supplied. This can be done by mixing small amounts of sugar or flour into the milk to thicken it. However, while this method reaches a similar texture as evaporated milk, it won't be particularly close in flavor.