I know this thread is a bit old, but after going to Jamaica I also searched high and low for an authentic jerk recipe, and mixed and matched a couple to come up with this, which I think tastes pretty authentic as a base for general jerk like that I was fed on the island. Of course in Jamaica everybody is proud of their individual and unique recipe's so "authentic" doesn't mean much... Lots of people like to add fruits, like mango/pineapple etc, theres no reason for you not to get creative, since any true Jamaican chef probably will. Lots of people use black pepper, but I don't like it in jerk...
* 1 bunch of green onions
* 1 scallion (or ~1/2 a small onion)
* 1-10 scotch bonnet peppers as desired for heat (you can substitute other hot peppers, but scotch bonnet is "authentic")
* 1 1/2 T allspice (a.k.a pimento - fresh whole berries are best, ground will also work though)
* 1 T fresh thyme (or 1 teaspoon dried thyme)
* ~1/2 inch fresh ginger root
* 3 cloves of garlic
* 1 T salt
* 1/2 teaspoon cinnamon
* 2 T of brown sugar
* Juice of 1 lime (can substitute a couple T of vinegar)
* 2 T soy sauce
* 2 T olive or vegetable oil
Basically just throw everything into a blender or food processor and grind it up until its a thick paste. Avoid the temptation to add more liquid for easier blending, you want it thick so it sticks to the meat.
Makes about 1.5 cups ... Probably enough to both marinate and coat about 10-12 chicken thigh's or breasts for grilling.
Cut a couple slices in the chicken or other meat for more absorption and marinate in the rub for 24+ hrs before cooking. Slow grilling (ie offset) or smoking (with pimento wood if you can find it) is best, the rub should turn black on the outside of the meat when its ready.