Shelf life, in months, of Cheez-Its. The flaky, baked 1-inch square cracker turns 100 this year. Trademarked in 1921, the cracker was originally marketed as “baked rarebit” and was promoted as a healthful snack that could counteract the “aggressive stimulating effects” of the modern diet. Because of its shelf life and nutritious ingredients, the cracker was a staple during the Depression and a mainstay of soldiers during World War II. Last year 400 million packages of Cheez-Its were sold in the U.S.