1Rinse the tenderloins, pat them dry, and trim off the silver skin and any excess fat. Place them in a shallow container or large resealable bag. Set aside.
2In a small bowl, whisk together the coffee, bourbon, molasses, vinegar, olive oil, and thyme.
Pour the marinade over the pork, and turn to coat on all sides. Cover, and chill in the refrigerator for at least 2 hours or overnight. (Turn the pork a few times to evenly distribute the marinade.)
3When you’re ready to cook the pork, prepare a hot fire in a charcoal or gas grill, and let the coals turn to gray ash with a slight red glow. Keep the coals on one side of the grill to create areas of direct and indirect heat. (If using a gas grill, heat just one side on medium.)
4Remove the pork from the marinade, reserving the marinade, and season with salt and pepper.
Boil marinade for 5 minutes before using to baste pork tenderloin.
Place the pork on the hot grill directly over the coals, and cook for about 12 to 15 minutes, basting with the reserved marinade and turning three or four times to avoid charring.
Move the pork away from the coals, close the grill or cover the pork with foil, and cook for another 3 to 5 minutes, until an internal thermometer inserted in the tenderloin reads 145-degrees for medium or 160-degrees for medium-well.
5Remove the pork from the grill, and transfer to a cutting board. Cover loosely with foil, and let it rest for 5 to 10 minutes. Slice the pork into small medallions (1/4 to 1/2 inch thick), sprinkle with a little salt (if you like) and serve warm.