if you're talking about a finishing sauce for pulled pork, this is one that will really be good. i cannot take credit for it though, this is from RIVET an member here who knows his stuff. i've tried this sauce and it's fabulous. if you must, you can substitute any beer, but it is best when the ones specified are used:
3 Cups Apple Cider Vinegar
1 Bottle (12 oz) Killians Irish Red or Guiness Beer
1 TBSP Salt
2 TBSP Red Pepper Flakes
1 TSP Ground Black Pepper
1/4 Cup Dark Brown Sugar
Mix all sauce ingredients in saucepan, bring to boil. Reduce heat to simmer and simmer 30 minutes, uncovered.
Once pork is pulled and chopped, mix in large bowl with sauce. Serve on buns with coleslaw.