We’ve all done it: Closed a bag of brown sugar, only to find it rock hard next time we went to use it. When brown sugar comes into contact with air, the moisture in the sugar evaporates, which causes the sugar to lump together.

You can prevent this by storing brown sugar in a zipper-lock plastic bag or in a tightly covered plastic container. Keeping it in the refrigerator will also help keep it fresh and soft. But if the damage has already been done, don’t worry: There are ways to reverse the hardening of your brown sugar.

Sifting may be a chore, but it can also be important, at least in some recipes. To truly understand the effect that sifting has on flour and cocoa powder, we baked two cakes—one with sifted flour, one with unsifted. The results revealed to us just how important this step can be.

We've all seen those recipes (including our own) that specify what kind of milk to use: whole, low fat, nonfat. But, in the end, does it really matter? We decided to test whole milk (which is 3 1/2 percent fat), 1 percent milk, and skim milk (which must contain less than 1/2 percent fat) in three recipes: pancakes, yellow layer cake, and chocolate pudding. Each recipe originally called for whole milk. The results varied and provided guidelines for the kind of recipe in which milk type makes a difference.

The easiest way to soften butter is to put sticks on the countertop and forget about them for an hour or two. But what if you don’t want to wait? Easy, you throw the butter in the microwave and voilà—you’ve got a couple of nubs of butter floating in a pool of melted goo.

Well, like everything else, there’s a method to these things, and after many tests (and several pounds of butter), we found a foolproof way to produce perfectly softened butter in a hurry.