Why You Should Use Milk Instead Of Water In Your Store-Bought Cake Mix

Store-bought cake mix may be a convenience item, but that doesn't mean that you need to settle for a mediocre dessert. There are a lot of different ingredients that can upgrade your boxed cake mix by adding more flavor, improving the texture, or making it more moist. Some of these, like maple syrup or brown butter, will add a lot to your mix, but at the expense of changing the flavor. Meanwhile, others, like mashed potatoes or whipped egg whites, work great but require an amount of effort that might defeat the whole point of using boxed cake mixes. But when talking to James Beard Award-nominated cookbook author Jerrelle Guy about flavorful substitutes for water in boxed cake mixes, there was one answer we got that packed a big punch without any of these downsides: a simple cup of whole milk.

Guy told us that whole milk "adds more richness, flavor and moisture because it has more fat." The boxed cake mixes often contain the flour, flavoring, and leavening agents, with some fat coming from added oil, eggs, or butter, but Guy is right that even with those other ingredients, boxed cake often lacks the richness that is key to making a tender cake. That's why you'll often see that one tip for upgrading cake mix is to add an extra egg. The issue there is that adding a whole extra egg (or something like more oil) may throw off the moisture ratio of the mix. So an even swap of milk for water is ideal instead.

Milk doesn't have a ton of fat — whole milk typically contains 3% to 4% milkfat — but that is just enough of a boost to your boxed cake mix without messing too much with the recipe. Fat will add some extra moisture and, most importantly, it will make your cake more tender. This is because fat coats flour, which prevents it from absorbing too much moisture, which slows the formation of gluten. That's good because gluten formation is one of the things that will make cakes tough and chewy instead of soft. Milk also has sugars and proteins in it, and both will not only make your favorite boxed cake mixes more tasty compared to using the recommended water, but both will also aid in browning when it bakes, adding even more flavor.

The best part is that the substitution is easy, adding exactly zero extra work to making a boxed cake with an ingredient that most people already have. You can actually just swap out the water in the recipe one-to-one for milk, and it will turn out great. The boosting effect of milk is going to be most clear in more lightly flavored cake mixes for recipes like white and yellow cake. It will work for chocolate cake, too, but that's one type of cake where milk can actually compete too much with the chocolate flavor. But even in that case, you may decide the added richness is worth it.