To make homemade A1 steak sauce, combine 1/2 cup of water, 1/2 cup of balsamic vinegar, 1/4 cup of Worcestershire sauce, 1/4 cup of ketchup and 1/4 cup of Dijon mustard in a saucepan. Squeeze the juice from one small navel orange in the pan and add 1/4 cup of raisins, 1/2 teaspoon of celery seed, 2 cloves garlic (smashed), 1/8 of an onion and cayenne pepper to the pan. Bring to a boil, simmer for 10-15 minutes, strain and reduce for another 5-7 minutes.
While the sauce is reducing after it has been strained, season to taste with sea salt and freshly ground pepper. The sauce tastes different when it is hot than when it is cold, so it is wise to leave most of the seasoning until the pan has been taken off of the stove. Remove the sauce from the heat when the thickness is to your liking.
The Kraft foods website maintains a sauce database, and the ingredients for the A1 Steak Sauce that Kraft actually markets are different than those involved in the homemade recipe. Storebought A1 sauce includes tomato puree, corn syrup, caramel color, xanthan gum and potassium sorbate. The potassium sorbate is used to preserve freshness, and the corn syrup is used to add artificial sweetness.