A frosting bag, also known as a piping bag or pastry bag, is a culinary tool that is used to apply icing and sometimes filling to cakes, cupcakes, éclairs, and other baked goods or pastries. There are different sizes and types of bags that are useful depending on need. A reusable frosting bag is typically made of cloth, plastic, parchment or nylon, while a disposable frosting bag is usually made of clear plasticine. Frosting bags used for decorative icing techniques are generally reusable and are fitted with decorator frosting tips.
Like frosting bags, decorator tips come in different sizes and the shapes of the openings produce different decorative results depending on the technique. In most systems, the tips are attached to the bag with a set of coupling rings that thread together to hold the tip in place on the bag. The tips are often interchangeable so that different shapes can be created from the same frosting bag. Some larger decorative tips used solely for frosting are fitted specifically to a bag and are not interchangeable. Piping bags are often disposable and can be created from rolled up parchment paper or plastic bags.
Professional pastry chefs, cake decorators and home baking enthusiasts typically employ reusable frosting bags for decorative techniques. They vary in weight and size, are sturdier, and are easier to control for tedious decorative techniques. For all their many benefits, reusable bags can be difficult to clean out and wash and stain easily from food coloring added to frosting. Conversely, while disposable bags are useful for quick, simple techniques and can be thrown out when finished, they are not as sturdy and often rip when using them with the stiffer decorator icings.
Frosting bags are useful even if decorative frosting techniques are not the goal. Instead of spatulas, bags can be used to more precisely and cleanly frost cupcakes and cookies and are also great for thinner icings. They are also useful for inserting cream fillings and can be used in cooking in addition to baking. A frosting bag makes the ideal tool for making cheese-filled shells or manicotti.
Frosting or pastry bags are widely available at kitchen, bakery and craft supply stores. Many retailers have kits available that come with a variety of bags and frosting tips. These kits are commonly sold for use in beginning to intermediate decorator techniques. Advanced techniques may require professional quality tools, which can be found in restaurant supply stores and catalogs or ordered online.