Most Sugars are made from white granulated sugar to which a dark syrup has been added.
Dark brown sugar has a mild molasses flavor and light brown sugar has a more delicate, lighter flavor. Dark and light maybe used interchangeably in most recipes. The label on Grandma’s Molasses says “You can easily make your own brown sugar as you need it by blending together 1/2 cup granulated sugar and 2 TB unsulfered molasses. The yield is equivalent to 1/2 cup brown sugar.”
Brown sugar is moist but if it dries out it will harden, so it should be stored airtight.
If it has small lumps they should be strained out. With your fingertips press the sugar through a large, wide strainer set over a large bowl.
If your brown sugar becomes hard, place it and a dampened (not wet) paper towel inside a resealable plastic bag. Leave overnight for 12 hours or more. A slice of apple can be used instead of a paper towel.