The process of human decomposition in a buried environment, known as taphonomy, is highly variable. Once a body is placed in a coffin, the rate and manner of its breakdown are influenced by a complex interplay of internal and external factors. The appearance of the remains after six months is not uniform, but depends on specific environmental and preparation conditions.
The Initial Process of Decomposition (The First Two Months)
Decomposition begins immediately after death with autolysis, or “self-digestion,” where the body’s own enzymes break down cells and tissues. This initial stage, starting in the internal organs within 24 to 72 hours, is quickly followed by putrefaction.
Putrefaction results from bacterial activity, primarily microbes from the gut, which consume tissues and release gases like methane and carbon dioxide. The accumulation of these gases causes the body to enter the bloat stage, typically three to five days post-mortem, though a coffin can delay this. Skin discoloration, often greenish due to blood breakdown products, may appear. Over the next few weeks, soft tissues begin to liquefy as bacterial activity progresses into active decay.
Appearance of Remains at the Six-Month Mark
After six months, the body is typically in advanced stages of decay, though preservation varies significantly. In an unembalmed body buried in a porous wooden casket, remains are often heavily skeletonized in areas with less soft tissue, such as the hands, feet, and skull. Remaining soft tissue loses substantial mass and appears dark, shrunken, and leathery.
If the coffin environment was wet and anaerobic (lacking oxygen), adipocere formation may have begun. Adipocere, or “grave wax,” is a grayish-white, waxy substance formed when body fat hydrolyzes into fatty acids, creating a firm, soap-like consistency that can preserve contours. Conversely, a very dry or cold burial environment may lead to mummification, where tissues desiccate and harden instead of liquefying. Even professionally embalmed remains will show change after six months, often appearing dehydrated and discolored beneath the clothing.
Environmental Factors That Alter the Outcome
The most significant variable influencing the six-month appearance is the presence and effectiveness of embalming chemicals, which contain fixatives like formaldehyde that slow microbial action. A well-embalmed body in a sealed metal casket and burial vault can remain relatively intact, showing only minor dehydration and discoloration. The integrity of the coffin acts as a barrier; a sealed metal casket reduces the exchange of oxygen, moisture, and microbes, significantly delaying decomposition.
Local soil conditions are also determinative. High soil moisture and warm temperatures accelerate microbial and enzymatic processes, leading to rapid skeletonization. Conversely, extremely cold temperatures or very dry soil can halt decomposition or promote mummification. Soil type also plays a role: clay soils hold moisture and slow decay, while acidic soils accelerate the breakdown of both soft tissue and bone.