Barbecue sauce

A spicy, sweet-tart sauce used to baste barbecued foods; also used as an accompaniment after the food is cooked. Traditionally made with tomatoes, onion, mustard, garlic, brown sugar and vinegar. Sugar is an important ingredient because it allows the sauce to caramelize during cooking, sealing in the juices. Barbecue sauce varies by region:
Kansas City: Thick, red-brown, tomato, molasses
North Carolina: Mustard, vinegar, black pepper
Alabama: White mayonnaise base
Arkansas: Thin vinegar-tomato base, spiced with pepper, sweetened slightly with molasses
Texas: Tomato base, hot chiles, cumin, less sweet