Injecting a beef brisket with marinade adds moisture and flavor to the meat, and breaks down the tough fibers to make it tender. Marinade or flavor injectors are large syringes and are available in many different sizes and materials. Ingredients such as apple juice, beef broth and vinegar are used to create a marinade that injects well into the beef brisket. Many competition cooks prefer to marinate the beef brisket to ensure that it remains flavorful and moist while it smokes for several hours.
Select a barbecue injector with a needle that has several holes. A needle with more than one hole will inject the marinade in all directions instead of single location.
Read the instructions that come with your barbecue marinade injector. Each injector may operate differently, so become familiar with how to use yours properly.
Create or purchase a liquid marinade to inject into the brisket. The type of marinade that you use will depend on your personal preference, but the marinade must pass through the needle without clogging it. Create a basic marinade by combining 1/4 cup Worcestershire sauce, 2 cups beef broth, 1 tsp. onion powder, 1 tsp. garlic powder and 1/2 tsp. cayenne pepper in a bowl. Refrigerate the mixture before you inject it into the brisket.
Prepare the brisket for injection before you plan to smoke it. Remove the excess fat from the brisket. Avoid seasoning it with a dry rub before you inject it and avoid refrigerating the brisket after you inject it, as this may cause the liquid to expel from the meat. Set aside 1/4 cup of the marinade for the injection.
Fill the meat injector with the liquid marinade. Inject the marinade into the meaty sections of the brisket parallel to the grain. Insert a very small amount into the meat because too much marinade will leak out of the brisket. Move the needle every inch until you completely cover the meat sections on the brisket.
Place the brisket in a colander to allow any excess marinade to drain. Do not leave the brisket out at room temperature for longer than 2 hours.
Reserve the excess marinade in a bowl, and use it to baste the brisket while it cooks.
Cook the beef brisket using your preferred cooking method.