Why You Should Pack Brown Sugar (and What Happens If You Don't)

If a recipe says "1 cup brown sugar," it almost always means 1 cup packed brown sugar. That is not how brown sugar comes out of the bag, and that is where home cooks lose track of their recipe.

What packed means

Brown sugar has molasses in it. The molasses makes the sugar sticky and creates air pockets when you spoon it into a cup. Loose, those pockets stay. Packed, you press the sugar down with the back of a spoon or your hand until the pockets close up.

To check that you packed it right, turn the cup over. The brown sugar should hold the cup's shape for a moment before falling out. If it just falls out as a loose pile, it was not packed.

Why this matters

Packed brown sugar weighs 213 grams per US cup. Loose brown sugar weighs about 145 grams per cup. That is a 30 percent gap. If the recipe wanted 213 grams and you used 145, you cut almost a third of the sugar.

Cookies turn out drier. Sauces taste less sweet. Bars and bread come out flat. The recipe still works, but it is not the recipe the writer made.

The easy fixes

• Use a measuring cup with straight sides (not a curved scoop). It packs more reliably.
• Press with the back of a spoon, the bottom of a smaller cup, or clean fingers.
• Level the top with a knife after packing.
• Or skip all of this and weigh: 213 grams equals 1 packed cup.

What if my brown sugar is hard?

Hard brown sugar still weighs the same per cup once packed, but it is hard to actually pack. To soften it: put a damp paper towel on top in a microwave-safe bowl and heat for 20 seconds. Or put a slice of bread in the bag overnight.