A sweet, slippery liquid, glycerin forms the backbone of fat and oil molecules. You can get food-grade glycerin, a byproduct of soap making, in bottles at drugstores, health-oriented grocery stores or the baking sections of supermarkets. Glycerin fills a useful role in cakes, cookies, icings candy and fudge by binding water in a form that makes its unavailable to molds, allowing baked goods to stay fresher longer. Glycerin has about 27 calories per teaspoon and is 60 percent as sweet as sugar.
Add a few drops of glycerin to recipes for royal icing for cakes and cookies to prevent the icing from drying out and forming a crust. Mix the glycerin with powdered sugar, egg whites and lemon juice.
Combine 1 to 2 tbsp. of glycerin with confectioner’s sugar, light corn syrup, water and unflavored gelatin to make fondant, a confectioner’s sugar frosting often used on wedding cakes. The glycerin keeps the fondant moist and malleable, master baker and teacher James Peterson notes in his text “Baking.”
Add glycerin along with corn syrup, water, butter and salt to sugar and cornstarch to make saltwater taffy. Stir the ingredients in a saucepan over medium heat. Stir the mixture until it begins to bubble and then let it cook without being disturbed until soft cracks appear, recommends the online site Science of Cooking. Add flavoring and food coloring and pour the mixture onto a shallow cookie sheet to cool.
Make nutrition bars by combining cereal or granola and whey protein in a mixer bowl. Add butter and vegetable oil to the bowl, followed by glycerin and water. Roll out the mixture to 3/8 inch, cut into pieces and bake at 400 F for 10 minutes.