Why you should always pack brown sugar
You probably have noticed that many recipes list brown sugar like this:
1 cup brown sugar, packed or 1 cup packed brown sugar
What does that mean? Why does it need to be packed?
Brown sugar should always be packed to press out the pockets of air that get trapped among the sticky sugar granules. Packing the brown sugar ensures that your measurements are consistent in all of your baking. Even if the recipe doesn’t specify that the brown sugar be packed, I still recommend it. (Note, if you want to be even more consistent, consider measuring by weight instead of volume)
To pack brown sugar, simply scoop it into your measuring cup with a spoon. Then gently press down with the back of the spoon until the sugar is compact, and repeat as needed until the cup is full. The top of the brown sugar should be flush with the top of the measuring cup.
By the way, did you know you can make your own brown sugar?