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.
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.