A sweet, mellow barbecue sauce invigorated with dark rum and apple cider.
Step 1: Place the cider, lemon zest, and lemon juice in a large, heavy saucepan and let it come to a boil over high heat. Let the cider mixture boil until reduced by about half, 4 to 6 minutes.
Step 2: Add the ketchup, brown sugar, rum, molasses, Worcestershire sauce, mustard, liquid smoke, onion powder, and pepper and whisk to mix. Reduce the heat to medium and let the sauce simmer until thick and flavorful, 10 to 15 minutes, stirring occasionally. Taste for seasoning , adding more rum and/or mustard as necessary.
Step 3: Transfer the sauce to a bowl or clean jars and let it cool to room temperature. Refrigerate the sauce until serving. It will keep covered in the refrigerator for 3 weeks. Reheat it over low heat before using.