Pastry bags, sometimes also called piping bags, can be used to fill pastries or to decorate cakes or pies. They are conical and have a small opening at one end and a large one at the other. Pastry bags are generally made from canvas or plasticized fabric. If you are working on a recipe that calls for a pastry bag and piping, you can make your own at home with some materials in your kitchen.
Plastic Sandwich Bag
Plastic sandwich bags are a popular substitute for pastry bags. They are useful because they are disposable, most homes have them and they are easy to handle. You can use zip-top bags, slider-tip bags or simple sandwich bags that have a fold-over top. Simply put the frosting in the bag and push it to one corner. Twist the top of the bag shut and place one hand at the back of the frosting. Snip the tip of the corner with a pair of scissors and begin piping. Begin with a small cut and gradually adjust if you want your pipes bigger. You can also snip the corner and place a metal pastry piper into the bag before you put the frosting in so that you can make designs.
You can use parchment, greaseproof or waxed paper to make a pastry bag. Simply cut the paper into a square. Then, fold it into a triangle by bringing one corner to the opposite corner. Roll the triangle into a cone so that the point will be where the frosting comes out. Tape the cone together. Add a metal piping tool and then the frosting. Fold the top of the bag down and begin piping. Paper is a popular substitute for pastry bags because most kitchens will have some variety of glossy paper.
If you do not have a pastry bag, plastic bag or waxed paper, you can create a makeshift pastry bag with a kitchen towel lined with plastic wrap. Simple lay the towel on the counter and cover it with plastic wrap. Roll the towel into a cone and pin it or tape it together. Put the frosting or filling into the cone and twist the top shut. You should only use this method to fill pastries and should not use it to make delicate decorations on pies or cakes.