Whole milk is about 3.25% milk fat. Half-and-half, despite its wishy-washy name, is usually around 10.5% to 18% fat. That’s a lot of creamy ambition. To bring it down to whole milk territory, you need to add water—not magic, not tears, just clean, cold water.
The ratio is dead simple: for every 3 parts half-and-half, add 2 parts water. That gives you 5 parts of a fluid that mimics whole milk. If you want to get technical, fill a 1-cup measure with half-and-half, then add enough water to make 1 and 2/3 cups. Stir it like you’re trying to wake it up from a nap, and boom—you’ve got whole milk.
Why This Works (And Why Your Great-Aunt Would Be Proud)
Milk is essentially a suspension of fat globules in water. Half-and-half is just that, but with more globules and less swagger. By adding water, you’re diluting the fat concentration down to a level that won’t make your cookies weep. It’s not a perfect replica—whole milk has a slightly different protein structure—but for cooking, baking, or cereal emergencies, it’s dead-on.
Fun fact: the FDA defines whole milk so strictly that you could theoretically sue someone for calling it whole milk if it’s off by a hair. But calm down—your homemade version won’t land you in dairy court. It’ll just work.
