Pastry bags and tips are great tools to have in the kitchen. They make it easy to add fillings to pastries and cakes as well as to shape doughs like pâte à choux uniformly. Cloth and vinyl bags can be washed and reused. Disposable bags are inexpensive and work equally well.
Pastry tips are available in a wide array of shapes and sizes. The number of the tip can tell you what size and shape it is. Plain round tips are numbered 2 though 6. Open star tips are numbered 14 though 84 and closed star tips are numbered 23 to 233. The smaller the number, the smaller the opening and the finer the design.
To fill a pastry bag, position the tip securely in the bag’s opening or in a coupler or tip holder. Fold down the bag’s top to create a wide cuff, then transfer the ingredient to the bag with a large spoon. Support the bag under the cuff with your free hand while filling it with the other.
Use a tall container to support the bag if you need to use both hands, folding down the cuff around the edge of the container. Fill the pastry bag only two-thirds full. Twist the bag to close it, compressing the mixture and releasing any air pockets.
To pipe, hold the bag at a 45-degree angle to the surface you’re piping onto, and use your dominant hand to slowly and steadily squeeze the bag. Use your other hand to guide and steady the tip. Release the pressure on the bag as you lift it away to make clean lines without tails.
To make a shell border, using buttercream, use a pastry bag with your choice of plain or star-shaped tip. The larger the opening of the tip, the larger the shells will be. Fill the piping bag and press out any air bubbles before you begin to avoid blowouts of icing as you work. Hold the tip of the pastry bag at a 45-degree angle close to the surface. Use even pressure to squeeze the icing out with one hand. Use your other hand to guide the tip of the bag. As you squeeze, lift the tip very slightly to allow the icing to fan forward in a rounded shape. When the shell is the size you want, ease the pressure on the bag and pull the tip toward you and down toward the cake, cutting it off. Continue making shells all the way around the cake, starting each new shell at the end of the previous one.
Whether you are piping decorations or making a border, it is always a good idea to practice on parchment or waxed paper before working on a cake surface. Wash the tips and reusable pastry bags thoroughly after each use in hot, soapy water and dry them completely inside out.