Here's my recipe for barbecue sauce. It's adapted from "Southern Barbecue Sauce" in Craig Claiborne's The New New York Times Cookbook.
BARBECUE SAUCE (click here for a printer-friendly version)
2 tablespoons unsalted butter
6 tablespoons cider vinegar
1/4 cup water
1-1/2 cups ketchup
2 tablespoons Worcestershire sauce
1/2 to 1 teaspoon Tabasco sauce
1/2 teaspoon garlic powder, or 1 teaspoon finely chopped garlic (I usually use garlic powder these days)
3 tablespoons vegetable oil, such as canola
1/4 - 1/2 teaspoon red pepper flakes
1 bay leaf
1 tablespoon smoked paprika
3 tablespoons molasses
salt (I don't add any) and pepper to taste
In a saucepan over low heat, combine everything but the lemon. Add the juice of the lemon, then cut the lemon into quarters and toss it into the pan, too. Heat the sauce thoroughly, but don't let it boil. You don't have to "cook" this for a long time--just heat it enough to blend everything. You can make the sauce while the meat is cooking.
Brush the sauce onto chicken or ribs in the last few minutes of cooking; otherwise, it will burn.
To save leftover sauce: discard the lemon. Store the sauce in a covered container in the fridge or freezer.
A FEW NOTES:
I have increased the Tabasco and red pepper flakes, which makes the sauce zippier but by no means really hot. Adjust it to your taste, of course. The original recipe calls for conventional paprika and much less of it. I like the character and depth of smoked paprika, which is now widely available. I think it adds a lot of character to the sauce.
The original recipe called for 2 tablespoons of sugar instead of molasses. For years, I left that out altogether. Lately, though, I have liked the Kansas City-style sauces I've had, most of which include molasses. That too has seemed to add some interesting flavor notes. After a little futzing, I found that I liked it with 3 tablespoons of molasses, but again, feel free to experiment and add more, less, or none.
Here's a trick with molasses: warm it briefly--like 10 seconds--in the microwave to make it easier to pour. (But be sure you've removed anything from the bottle that has foil in it! I ignited the bottle of molasses the other day because the top of the bottle still had a bit of the foil seal on it. It was very dramatic.) To measure the molasses, use the spoon that you used for the oil without washing it in between: the remaining traces of oil will let the molasses slide easily out of the spoon, and you won't waste any.
I try to be careful to keep this from burning. Low heat (indirect, if possible) is the key. Watch it closely. I often apply the sauce a couple of times, though for ribs, I will usually just coat them once thoroughly.
We usually have bowls of this on the table for people to use to dip their meat into if they choose.