Dry rub will: 1) enhance the appearance of food 2) help to seal in the juices and the flavor they contain 3) compliment the food's flavor: sugar, salt, spice = yum! 4) create a delicious crust or 'bark' on meat. Dry rubs developed and sold by restaurants have usually been tested and perfected over years. A great many dry rubs contain sugar, salt, pepper, and paprika as a base.