Do not mistake weight ounces with volume ounces when measuring powdered sugar. Know exactly how much you are purchasing. Everyone is aware that one cup equals eight ounces, right? In actuality, when measuring components for a recipe, 1 cup does not necessarily correspond to 8 ounces.
We know that 1 cup of water weighs 8 ounces, but because honey is more viscous than water, 1 cup of honey weighs 12 ounces. Powdered sugar directly from the box or plastic bag weighs 4 1/2 ounces per cup; therefore, a 1-pound box (or 16 ounces) provides approximately 3 1/2 cups of powdered sugar. If a recipe asks for powdered sugar, 4 ounces of powdered sugar will equal 1 dry measuring cup.
Powdered sugar becomes lighter and fluffier when sifted, so it occupies more space in the cup.
How are 2 cups of sugar measured?
WHITE GRANULATED SUGAR – Unlike flour, sugar is measured by filling a measuring cup or spoon to the brim and then leveling it with the back of a knife. Because sugar is heavier than flour, it is less prone to settle in the measuring cup. Additionally, it is more forgiving than other ingredients in recipes because the sweetness of a final dish relies on the individual’s taste buds.