Barbeque Sauce is a sauce used to accompany barbequed or grilled food. It can be applied to the food during cooking (becoming a “basting sauce”), or served with the cooked food, or both.
The sauce becomes particularly important when the barbequing in question is actually “grilling” over propane, to compensate for there being no wood smoke to impart a flavour to the food.
Some maintain that Barbeque Sauce should only appear when the meat hits the table, and never be applied during cooking at all. Sauces that are applied only at the very end of cooking (such as White Barbeque Sauce) or only served at the table are called “finishing sauces.”
There are thousands of recipes for Barbeque Sauces, with no common base for all of them aside from their purpose.
They can be categorized, though, by generalisations or by region: some are vinegar based, some have tomato, some have no tomato, some may add alcohol. Most use sugar. Most commercially-sold Western barbeque sauces have tomato in them. Chinese barbeque sauces tend to be based on vinegar, hoisin sauce, sesame (oil or paste) and sometimes bean sauce.
In America, the following regional generalisations can be made as a starting point for discussion (usually vigorous):
- Texas: Tomato-based, spicy;
- Midwest: Tomato-based, spicy;
- West: Citrus fruits, fresh herbs, oils;
- American south: Vinegar based.
When you get to the Carolinas, though, you have to switch from broad regional swaths to practically looking it at county-by-county. Roughly, though, Carolina barbeque sauces can be grouped as:
- Eastern North Carolina (east of Durham): Vinegar-based, no tomato;
- Piedmont North Carolina: Vinegar-based, some tomato;
- Western North Carolina (west of Durham): Small amount of vinegar, large quantity of tomato;
- South Carolina: Mustard-based, often some tomato;
- Charlotte: Small amount of tomato.
Similar regional categorizations could also be done for almost any American state where barbeque is a religion, such as Texas and Georgia.
Asian barbeque sauces such as Japanese are an art in their own right.
Many men who otherwise would have to be dragged screaming into a kitchen will happily spend hours there concocting their secret, world’s best barbeque sauce.
Barbeque sauces tend to burn easily because of the sugars in them, and turn black owing to tomato content.
When you’re grilling a steak that’s maybe only going to be on the grill 5 to 15 minutes in total, you can slather the sauce on before you slap the steak on the grill. If you’re grilling something that’s going to be on much longer, such as pork or a piece of chicken, apply the barbeque sauce during the last 10 to 15 minutes of cooking, or it will just go black, crusty and horrible.
An eastern North Carolina barbeque sauce, provided as an illustration of a tomato-free version:
2 cups (16 oz / 500ml) cider vinegar
2 tablespoons brown sugar
1 1/2 tablespoons salt
1 1/2 teaspoons of crushed red pepper flakes or hot chile pepper flakes
1/2 teaspoon cayenne pepper
1/2 teaspoon ground black pepper
Mix. Ideally, make a few hours ahead to allow flavours to marry.
A 2010 study at the University of Western Ontario in Canada found that barbeque sauces tend to be high in natural antioxidants, even after cooking, owing to the ranges of spices, herbs, fruits and vegetables which go into them. The study was published in the Journal of Food Composition and Analysis. 
Some food researchers feel that barbeque sauces that have no tomato in them (such as those in some parts of the Carolinas) may be vestiges of the first ketchup sauces, which had no tomato in them.
Spice Up Your Health This Barbecue Season. Communications Staff, University of Western Ontario. 23 March 2010. Retrieved 24 March 2010 from: http://communications.uwo.ca/com/media_newsroom/media_newsroom_stories/spice_up_your_health_this_barbecue_season_20100323445996