1) Break the spine of the pig with a cleaver from head to tail to allow the animal to lie flat on the barbecue. Marinate the pig for 2 hours before placing it over the coals.
2) Prepare the barbecue pit with coals. The coals are ready when they glow and are covered with a white ash. Have extra coals and oak wood on the side to add to the fire when needed, enough to keep the fire burning for 3 hours.
3) To gauge the temperature of the fire pit, hold your hand a meter away from the coals. You should be able to hold your hand over the fire for 4 to 5 seconds before pulling it away. If you can hold your hand longer over the fire, it means there is not enough heat, if less, the coals are too hot.
4) Remove the pig from the marinade. Place the pig rib cage facing down towards the coals and cook for about 2 1/2 hours. Do not leave the fire unattended. Turn the pig on to its back and cook for another 1/2 to 1 hour, or until the pig's skin is crisp and the internal temperature reaches a minimum of 70 degrees C on an instant-read thermometer.
5) Throughout the cooking time, check the fire temperature constantly and move the coals around to create a uniform temperature to prevent burning the pig.
6) Once the pig is done cooking, serve with fresh salads, chimichurri, and plenty of Chilean wine.
For the marinade:
Mix all ingredients together in a bowl. This marinade can be prepared a day in advance.