Does Bourbon-Dijon sauce need to be capitalized?

Question

Wondering if Dijon needs to be capitalized in our menu. "...served with a bourbon-dijon sauce."

Answer 1

Capitalize Dijon but not bourbon: bourbon-Dijon sauce.

Ingredient name capitalization is a matter of style, however most style guides run along these lines:

Personal, national, or geographical names, and words derived from such names, are often lowercased when used with a nonliteral meaning. For example, the cheese known as “gruyère” takes its name from a district in Switzerland but is not necessarily from there; “swiss cheese” (lowercase s) is a cheese that resembles Swiss emmentaler (which derives its name from the Emme River valley). Although some of the terms in this paragraph and the examples that follow are capitalized in Webster’s, Chicago prefers to lowercase them in their nonliteral use.
_{Source: The Chicago Manual of Style (login required)}

Here’s a partial list from The Chicago Manual of Style:

bordeaux
brie
brussels sprouts
burgundy
champagne
cheddar
dutch oven
frankfurter
french dressing
french fries
french windows
gruyère
scotch (but Scotch whisky, a product of Scotland)
stilton
swiss cheese (not made in Switzerland)
wiener

Check with sites that have editors on duty. Here are a couple examples:

These rib eye steaks are marinated in a delicious bourbon-Dijon mixture . . .
_{— The Spruce Eats}

1 ½ teaspoons Dijon mustard . . . 2 teaspoons bourbon
_{— New York Times Cooking}

1/2 cup bourbon . . . 1 tablespoon Dijon mustard
_{— Epicurious}

Expanded musings at Grammarphobia — How to capitalize food names

Sometimes the authorities get involved: New York Times — Is Gruyère Still Gruyère if It Doesn’t Come From Gruyères?