My dad always takes half-and-half in his daily cup of coffee, so if he's in a grumpy mood in the morning, it's probably because he had to use a half-and-half substitute in his coffee. Regular milk just doesn't cut it, he insists, and I have to agree. The flavor and texture that half-and-half gives to coffee is so much tastier and richer than even the best whole milk. But half-and-half isn't just good for coffee. You can use half-and-half in cream-based pasta sauces, quiches, even cocktails. But what is half-and-half, and how is half-and-half different than heavy cream? And what can you use as a reasonable half-and-half substitute if you forgot to pick up a new carton at the store?

As the name suggests, half-and-half is a combination of different types of milk—in this case, milk and cream. In the United States, half-and-half is legally defined by the US Food and Drug Administration as, "the food consisting of a mixture of milk and cream which contains not less than 10.5 percent but less than 18 percent milkfat."

However, there are no regulations that say that half-and-half must be half-cream, half-milk. The mixture could be two-thirds milk and one-third heavy cream, or one-quarter milk and three-quarters cream, as long as the fat content is correct.

So if you're looking to make half-and-half at home, you totally can, but the ratio of milk to cream that you should use depends on what kind of milk and cream you have on hand. As Christine Gallary writes for The Kitchn, you can make half-and-half by mixing ½ cup of whole milk and ½ cup of light cream, or ⅔ cup skim or low-fat milk and ⅓ cup heavy cream, or, if you’re really committed, “4 teaspoons melted unsalted butter in a measuring cup, then add enough whole milk to equal 1 cup.”

But, to be honest, by the time you're mixing light cream or heavy cream with whole milk to make half-and-half for your morning cup of coffee, you might as well just use the cream. Cream has a higher fat content than regular liquid milk, so you'll get that richness and sweetness of half-and-half with none of the wateriness of whole milk. Sure, it might be a little decadent, but, if you ask me, desperate times call for more fat.