Here is my beefy injection (and AuJus) that I use on a variety of beef products from brisket to prime rib.
Brisket – Chuck Roast Injection & AuJus
1 14 oz can Beef Consume
1 packet Lipton Beefy Onion Soup (dry mix)
1-1/2 of the soup can cold water
5 teaspoons Worcestershire sauce
2 splashes of Soy Sauce
1 teaspoon of garlic salt
2 teaspoon Herb-OX beef bullion (or other beef bullion)
2 teaspoons Montreal Steak rub
1 teaspoon Smokin’ Guns Rub**
1/2 teaspoon celery seed
1/2 teaspoon black pepper
Bring ingredients to a low simmer in a saucepan, and cook for 15 to 20 minutes.
Try to avoid having the liquid come to a boil. Additional water can be added if flavors are too strong, or if liquid gets too thick. AuJus is a thin table sauce, NOT a gravy. Pour through strainer to remove the onions and coarse pieces from the Montreal Steak rub. Serve warm.
To use an injection, cool the liquid, and chill overnight. Skim any fat. Inject 3/4 to 1 ounce per pound at least 2 hours before cooking.
**Smokin' guns is a competition grade BBQ rub which contains MSG.
If you want to explore the use of phosphates there are several competition grade of injections in powder form that you can mix with water or beef broth. Big Poppa Cattle Prod, and Kosmo's Reserve Blend Beef are two that I like. I do mix them lighter than the 'competition' instructions. Check out your local Ace Hardware, many stores are carrying Kosmo's products.