Place pork roast in a shallow glass or plastic dish.
Mix ground red chiles, lime juice, 1 teaspoon of salt, cumin, oregano, pepper, garlic and ¼ cup of orange juice concentrate, then brush mixture onto the pork roast.
Cover and refrigerate for at least 8 hours.
Heat oven to 325°F.
Place pork, fat side up, on rack in a shallow roasting pan. Insert meat thermometer so that the tip is in the center of the thickest part of the roast and does not rest in fat.
Roast uncovered until thermometer registers 170°F, about 2 to 2 ½ hours.
Remove pork and rack from the pan. Strain the drippings from the pan and set aside.
Add enough water to remaining orange juice concentrate to measure ¾ of a cup. Stir juice and wine into drippings. Stir in sour cream and salt.
