Tomatoes
Pureed berries from the famously toxic nightshade family. The leaves and stems are poisonous, but the fruit is eminently edible. All tomatoes—not just varieties called “beefsteak”—contain about 0.25 percent glutamic acid, one of the savory chemicals that gives beef its meatiness. Concentrated tomato fiber also imparts thickness.

Raisin Paste
A key ingredient since chef H. W. Brand added it to King George IV’s steak sauce in the 1820s. Raisins contain antioxidants, which may have helped mask the rancid flavor of spoiling meat in the days before refrigeration.

Distilled Vinegar
One of the oldest meat tenderizers. Earlier versions of A.1. used tastier (but more expensive) malt vinegar, which is made from unhopped beer. The distilled variety is made from industrial vats of pure ethanol.

Corn Syrup
Here, as in so many other American foods, corn syrup is used as a sweetener and thickener.

Salt
When salt hits the taste buds, it suppresses the perception of bitterness. One tablespoon of A.1. (and who really uses that little?) contains an eighth of your recommended daily dosage of sodium.

Crushed Orange Puree
Older versions of A.1. used marmalade made with bittersweet Seville oranges. The switch to a puree is likely more apparent to the nose than to the tongue.

Dried Garlic and Onion
Beef has scores of sulfur-based flavor compounds, most notably hydrogen sulfide. Since garlic and onions also contain sulfur compounds, they can help make even the lousiest cuts taste richer and “meatier.”

Spices and Herbs
A corporate secret, of course. Celeb chef Alton Brown told us that he thinks it could include dried mushroom powder, allspice, white pepper, and anchovy.

Caramel Color
Sugar or similar carbohydrates browned at about 130 degrees Fahrenheit. The brown tint eliminates the red of the tomatoes, ensuring that this steak sauce won’t look like rebranded ketchup.

Xanthan Gum
A polysaccharide excreted by the Xanthomonas campestris bacterium, this gummy substance has a peculiar viscosity: It thickens the mix, stabilizing the ingredients, but when shaken or poured, it behaves in a more liquid manner.