Ace's Restaurant Black Jack Barbecue Sauce

Source: Chef Michael Cross, Ace's Restaurant, Sacramento, California

2 3/8 ounces butter
1 1/4 quarts yellow onion, sliced
1/3 cup garlic cloves
1/3 cup chili powder
1 1/4 quarts tomato ketchup
5/8 cup apple cider vinegar
1 1/4 quarts Worcestershire sauce
1/8 can chipotle peppers
1/8 bottle whiskey
3/4 pound brown sugar
5/8 teaspoon liquid smoke flavoring
Salt to taste

Sweat the onions and garlic in the butter until soft. Add the chili powder and cook for two to three minutes. Add the remaining ingredients. Simmer until reduced to desired consistency. Blend using a hand blender. Correct the seasoning, then cool, label and store.