Before we proceed into a brief explanation of the various bacterial and chemical processes involved in turning a deceased individual's body fat into adipocere, we need to define what adipocere is.
Adipocere is a soapy, waxy, and in some instances, cheese-like substance derived from the fat and soft tissues of a deceased person or animal; it is a by-product of the natural process of decomposition. It may form in semi-moist or very wet environments, hence the relative terms of "dry" and "wet" adipocere. It can be a creamy white color, gray, or even a shade of tan, brown, or almost black. Early in its formation, adipocere gives off a pungent odor similar to ammonia, though this may be difficult to discern in situ due to other decomposition gases (cadaverine, and putresine, for example). Later, adipocere may be rank and cheesey, or sweet-smelling, or it have no odor at all. It can be heated to a plastic-like state, melted, clarified, or burned. Its consistency varies, from being gooey as with a mushy bar of soap, to semi-soft like with a young cheddar cheese, to hard and grainy, as with candle wax.
Adipocere forms in and on dead animals in the absence of free oxygen but also in a wet, cool environment, such as a water burial (a drowning victim, for example), an airtight but moist crypt, or a moist grave. Regardless of casket, coffin, or burial shroud, adipocere formation is possible in an underground burial. Its odds increase with a corpse inside a casket enclosed by a burial vault. An overweight body contains enough water to begin adipocere formation in a casket, sealed or not. Regardless of the triggering mechanism, the end result is popularly known as a "soap mummy".
In the tragic circumstance of a newborn infant's death, the necessary bacteria may not have had the time or opportunity to establish themselves in the child's digestive system while she was alive. Therefore her remains may not enter the normal decomposition cycle, but instead will follow nearly directly into adipocere formation. Because of the extra fat a baby carries, nearly all of her body may turn into adipocere. Occasionally, this is seen in the corpses of older children and adults as well. In the past as well as presently, adipocere formation is regarded by some as being a holy sign of "incorruptibility" (see History Page for more on the subjest of so-called incorrupt bodies).
Typically, visible adipocere formation will begin about one or two months after death, continuing to whatever degree of ultimate completion after about two years. In bodies submerged in water, adipocere may form sooner, possibly within three weeks of death. Prior to any possible adipocere formation, the corpse goes through several stages of decomposition. Although there can be some variation with these, the basic stages are, in usual order:
Algor Mortis- Life ceases. Higher and lower brain functions cease, as does respiration. The heart stops beating. The body's temperature starts to drop to whatever the ambient temperature is. Body is limp. Urine or feces may be expelled if gravity allows for it.
Livor Mortis- Within a few hours of death, blood pools at the lowest portion of the anatomy; often referred to as "lividity". Characterized by large dark red splotches on the corpse. The rest of the body appears much paler than normal. The embalming process will, among other things, remove this blood and substitute a preservative solution.
Rigor Mortis- A stiffening of body muscles due to a build up of lactic acid, among other chemicals, as a result of the early decomposition of muscle fiber. Passes as quickly as it comes, usually a day or so, starting within the first day after onset of death. Insects may begin to lay eggs in the corpse. There may be an anal discharge of any remaining stools.
Putrefaction- Certainly the least pleasant stage of the decomposition process. Begins within three days of death. Many insects visiting and laying eggs. Corpse starts to change color with "streaking" along near-skin surface arteries and vessels, as blood begins to decompose. Skin color also darkens. After several days, insect larvae may begin to crawl out of the body. Scavenging animals (former pets, rodents, etc.) begin to partake of the meal. By a week after death, gases produced by bacterial and chemical processes begin to cause bloating of bodies. Internally, the bacteria that all humans live with every day, such as those found in the digestive tract, continue working on. But instead of the friendly bacteria's food source being what humans eat for food, it is now the dead human body itself which is consumed. Internal organs begin to liquefy. Within two weeks from onset of death, there is a bloody purge of putrefying liquid from the mouth, nose, anus, or any other opening. The stench from the rotting corpse is overwhelmingly powerful, if within an enclosed space. Soon, within weeks, the body bursts open under pressure, spilling its contents. Reeking liquids sink into whatever is under the corpse, be it a casket lining, a bed mattress, a floor, or soil. Vast quantities of insect larvae may pour out of the body, if insects have had prior access to it. Scavengers may pick apart the corpse, which tends to fall apart quite easily in this stage. At this point the dead body has become a very messy and nasty object, not one likely to endear any nearby living human.
Mummification (or) Adipocere Formation- This is the terminal stage of decomposition for the soft tissue portion of corpses, which for one or several reasons were not consumed by bacteria, insects, or scavengers. In the case of mummification, this end process begins approximately one month after death, though it may begin sooner if conditions are right.
Mummification occurs when a body dries out, through either natural or artificial means (as with the Egyptian mummies). Two circumstances are required for mummification: first, a dry and low humidity environment whether hot, ambient, or cold; second, a corpse with a low body fat mass (in general, a thin person). Rarely do even slightly overweight humans mummify under natural circumstances, as any county medical examiner's office field technician will readily testify.
A corpse with an above-average body mass will either decompose (putrefy) all the way to a skeletal state, or will enter into an adipocere formation stage (assuming that there is little or no exposure to air). This is the key to adipocere formation; the bacteria that convert the body's fat to adipocere are anaerobic. These bacteria digest body fat, excreting adipocere and ammonial gases. They do not work well when exposed to air, which is why adipocere rarely forms on body parts exposed to air. Another important factor is the limiting of scavengers and insect larvae. Obviously, a corpse cannot enter into an adipocere formation stage if all of its soft tissues have been consumed.
Any fat in or on the corpse will be subject to adipocere formation under the proper conditions, including soft organ tissues such as eyes, brain, liver, pancreas and heart. As a matter of fact, autopsies performed on freshly deceased bodies will sometimes reveal small pockets of adipocere, in the fatty tissues of diseased organs such as the liver and pancreas. It's apparent that portions of these organs had begun to die weeks or even months before onset of the body's complete death. Occasionally, virtually all the flesh on a body is converted into adipocere; i.e., both the fat and muscle. The mechanism behind this "total formation" phenomenon is still not very well understood. Among other things also not well researched is why adipocere formation is more likely upon flesh covered with clothing, and why certain clothing or coverings (synthetic materials, like polyester) seem to promote adipocere more than natural fabric, such as cotton.
Adipocere formation appears to benefit from a catalyst- some sort of alkaline source, such as formaldehyde which is commonly used in embalming fluid. Unwittingly perhaps, our so-called "modern" embalming and burial processes have probably resulted in much more adipocere formation than might otherwise have occured. The usage of "sealer" caskets, in either above-ground entombments or below-ground burials, may also increase the occurrence of adipocere, as these devices prevent aerobic bacteria and insects from carrying out their life cycles, which typically aid in producing a skeletal or dessicated condition of the corpse. Mausoleum entombment by itself, depending on the design of the mausoleum, may also encourage the formation of adipocere.
A cold, hard truth is beginning to work its way to the surface about North American embalming and burial/entombment practices: many- and perhaps most- dead bodies interred within USA and Canadian cemeteries during the past century are still largely intact, "down there"- and it's all due to adipocere formation. The grisly image of millions of buried and entombed soap mummies might not be serene, but it is apparently a shocking reality.
Certain soils are highly alkaline, contributing to adipocere formation as well. An alkaline source acts on a corpse's fat in much the same way that lye acts on vegetable fat- by hydrolizing it; that is, turning it into a sort of soap. This chemical process is called saponification. Adipocere formation is often referred to as saponification. And thus, soap mummies are born.
During exhumations within the war-torn Balkans in the 1990's, a team of United Nations forensics experts estimated that 22% of the bodies found in one area were largely preserved to one degree or another by the process of adipocere formation. These bodies were those mostly of civilians, murdered in massacres commited by one side or another in the various Yugoslavian secession wars. Keep in mind that these bodies were almost always found with trauma from multiple gunshot wounds, were found unembalmed and buried in their clothing without coffins (though sometimes they were found in bodybags), and had been placed side by side in rows or piled up in pits dug out by bulldozers. These bodies were then buried using those same bulldozers by the killers.
Let's look at some well-established facts: we know that the largely American-only practice of placing caskets (especially metallic ones) inside concrete or metal burial vaults dramatically increases the odds of adipocere formation. We know that embalming (also a largely American-only practice) increases the odds of adipocere formation. We also know that burial in wet graves (a rather common occurence in American cemeteries, what with all the watering of the grounds, besides any groundwater present), also greatly increases the likelihood of adipocere formation. Therefore, we can come to a plausible conclusion and estimate that perhaps 100 million corpses in American cemeteries have become largely saponified. By any measure, that is a huge number, and one likely unrivaled by any other nation. Thus we arrive at a possibly disturbing realization that the USA is very likely the world's epicenter for adipocere.
Of course, adipocere would never form without bacteria initiating the proper and necessary chemical and biological processes. Certain endogenous bacteria (such as clostridium welchii) are naturally occuring in the soil and our digestive tract. Normally these will have no affect on a healthy, living creature. Once the body is dead however, as indicated above, these bacteria begin their life cycles anew, until their food source is consumed or otherwise made unavailable.
The formation of adipocere upon a corpse by certain bacteria inhibit the growth of still others. Bacteria which would normally digest abdominal muscle tissue is stopped cold due to adipocere "blocking the way". This is but one example of adipocere's fascinating existence. It has the capability to preserve fatty and non-fatty tissues (organs, nerves, muscles, tendons, etc.), long after the rest of the remains would have been consumed.
Eventually though, it is almost certain that virtually all adipocere will decompose. Scientific research shows that certain Gram-positive bacteria, such as from the enterobacteria family, will eventually utilize adipocere as a food source after other nearby sources are depleted. But it may take many years, perhaps hundreds, or even thousands of years, for this to happen. Adipocere-preserved human and animal remains thousands of years old have been found. The recently discovered dinosaur heart and other organs, many millions of years old and fossilized, were preserved by way of adipocere formation!
It's all quite fascinating. When ideal conditions exist, adipocere does not get broken down into smaller elements even by enterobacteria. This is VERY rare, however. Dinosaur hearts don't just happen along every day! But in Ohio and elsewhere, shale concretions demonstrate that indeed adipocere can be preserved, albeit in a solid form. The current theory is this: Dead animals such as fish, sank to the bottom of a body of water, where they were converted by bacteria into adipocere. Immersed in water devoid of free oxygen, such as in the silt bottom of a deep lake, these remains did not decompose as would normally occur. The adipocere formed from many animals great and small became nuclei for what is known today as a "concretion formation". Silt, organic debris and other clumps of adipocere formed still larger clumps of matter called organic concretions. These formed in shallow or deep depressions at the bottom of freshwater lakes. These eventually turned into concretion formations, as the lake beds changed into solid earth.
Over a very long period, due to plate tectonics, these concretions found themselves deep inside the Earth's crust. Over millions of years and under tremendous heat and pressure, they changed and evolved, becoming carbon-based shale, or possibly even fossil fuels such as petroleum and natural gas.
Today, millions of years later, the results of some of these organic concretions can be seen as round "rocks", somewhat resembling streamlined boulders. The adipocere has been chemically altered, in this case, into shale (see the Images1 Page for a photo of this phenomenon).
We life forms on Earth share one thing in common with fossil fuels: we are all carbon-based. Ashes to ashes, dust to dust. Carbon to man. Man to adipocere. Adipocere to carbon. What goes round may come around. "HOMINIS FACTVS ADIPIS CERA"
