Body Decomposition

How long would it take for a human corpse to decompose enough to where it is more or less just a skeleton?

I don't have a tag, but I am a crime scene investigator so this falls into my area somewhat. Decomposition depends on a long list of factors - the size and condition of the body, the humidity, the temperature, access to predators, etc.

Decomposition usually starts in the gut as the digestive system breaks down and digestive enzymes and bacteria start to consume the rest of the body. That will start to happen after death no matter what the circumstances, though cold temperatures will slow the process. This is one of the reasons bodies at the morgue are refrigerated. On the cases I have had where people died in their homes with the A/C running, decomposition might be slowed, but it was still obvious in the breaking down of internal organs, drying of the extremities, etc., after a few hours.

Bodies left in a forest in Florida may skeletonize within a couple of weeks. It's warm, hot, and humid, so bacteria that break down dead tissue thrive. That climate is a great incubator for all that stuff in the gut. It's also friendly to insects, which will quickly land and lay eggs to add maggots to the mix. In a training program, I saw a dead pig reduced to bones in about four days under those conditions. It was sheltered under wire so large predators weren't even a factor, the majority of the work was done by bacteria and insects.

In a cold northern forest, skeletonization might take much longer. A temperature drop will impair both bacteria and insect activity and might be more favorable to mummification (soft tissue and skin dries out in place) rather than total skeletonization. I've had a couple cases where people died in shelters that were undisturbed for months. The individuals happened to be thin to start with (less body fat is more conducive to mummification) so by the time they were found, both were essentially skeletons with papery skin still in place. Not sure of the condition of the internal organs, but the bodies were completely dry and weighed very little.

What if it's in a coffin?

Depends on the type of burial. Once water gets into contact with the body, things speed up. Old wooden coffins didn't last all that long and most weren't waterproof to start with. Modern burials often have concrete vaults that protect the coffin and the body within much better.

Source: Reddit