In a medium saucepan over medium heat, cook the diced bacon until crispy. Remove any excess fat from the pan and add the demi-glace, red wine, cola, pineapple juice and pineapple tidbits. Bring back to a simmer over medium-high heat for 10 minutes, until the sauce has reduced by half. Slice the pork loin and serve with the sauce on the side.
Preheat your oven to 350 degrees F.
Combine 1 cup of warm water with the vinegar, sugar and salt in a medium bowl, whisking until the sugar and salt are dissolved. Transfer to a large resealable gallon-sized plastic bag. Add 1 cup of cold water and the pork loin, seal, and refrigerate overnight.
Pulse the coffee, brown sugar, peppercorns, star anise and cinnamon stick in a coffee or spice grinder until they become a fine powder. Remove the pork loin from the brine and pat dry with paper towels. Rub with the spice mix, transfer the pork to a baking sheet and set it aside at room temperature.
In a large skillet melt the butter with the oil over medium-high heat. Add the pork loin and brown for 5 minutes, turning to brown all sides. Transfer the pork to a baking sheet and roast until the temperature reads 160 degrees F on an instant-read thermometer, about 1 hour. Remove the roast from the oven, cover loosely with aluminum foil, and let it rest for 10 minutes before slicing.