Dead Folks and Decay

14 May

I received an interesting question from a writer the other day about adipocere formation in a corpse. I thought it might be interesting and helpful to look at what happens to a body after death. The destruction of the human body begins immediately after death and can follow one of three major pathways: putrefaction (decay), mummification, and adipocere formation.

Putrefaction is the process of tissue destruction due to bacterial growth.  The bacteria responsible for putrefaction almost universally come from within the bowels of the deceased and very rarely from the environment. Bacterial growth is enhanced in warm and moist environments and is delayed in cooler and drier climates. This means that a body will decay much faster in a swamp in Louisiana in August than it will in the Colorado mountains in April. The end result of putrefaction is a skeleton. Given the proper conditions and enough time, all the tissues of the body will be consumed by the putrefaction process and only the bones will remain. If in your story you have skeletal remains please, please do not have the bones connected together as the skeleton you saw in science class in high school. ALL the tissues decay, including the ligaments and tendons that hold the bones together, which means that a completely skeletonized body will simply be a pile of bones.

The second way a body will undergo postmortem alteration is by mummification. This occurs more readily in very dry climates and particularly those where there is high heat such as a desert location. It can also happen in the high mountains where the air is often very dry and has been seen in basements, attics, and in corpses walled up in building walls and crawl spaces. Nightmarish. Basically what happens here is that the corpse desiccates (dries out) fairly rapidly.  If the body loses water so rapidly that the bacteria within do not have time to significantly putrefy the body, a mummy will be the end product. The corpse will be dry and leathery very much like beef jerky. In fact, the processes are identical since mummification and making beef jerky both require that tissues be completely dried out.

The third method of alteration is by adipocere formation, which is the result of a chemical process called saponification. Basically soap making. Adipocere is caused by a reaction between certain bacteria and the body’s adipose (fatty) tissues. Bacteria such as Clostridia perfringens, the bacterium that causes gas gangrene, convert body fat into oleic, stearic, and palmitic acids, the primary constitutes of adipocere. The result is a whitish-gray or brownish, greasy or waxy substance, which can cast the body in a doll-like fashion. On first glance the corpse might appear to be a manikin or as if it had been carved from a large bar of soap. This most often occurs in bodies found in water or warm, damp areas and usually takes several months to form so that adipocere formation is a broad indicator of time of death.
Bodies do not always decompose uniformly or in the same way. A corpse might be partially skeletonized, partially mummified, and partially converted to adipocere. Adipocere looks like this:


This photo is of two child victims in the famous Hoptoun Quarry Murders Case investigated by Sir Sydney Alfred Smith. Read the full story HERE.

So when you have dead folks in your stories just remember they don’t all have to decay or turn into a pile of bones because there are a couple of other very spooky things that can happen to dead folks.


Posted by on May 14, 2009 in Time of Death


37 responses to “Dead Folks and Decay

  1. Jeri Westerson

    May 14, 2009 at 9:45 am

    Doug, that is gloriously gross. I love it!


  2. Basil Sands

    May 14, 2009 at 9:56 am

    Good information. Death has so many iterations and so many facets of presenting itself that I find myself learning all the time.

    Years ago I was an EMT in a rural community on the Alaska highway system and saw my fair share of dead folks. Usually they were quite recent, minutes or hours, beyond mortality. The thing that always got me was not the decomposition, but the noises that come from a recently dead body.

    I remember the first time I picked up a patient dead of cardiac arrest. Our regs stated we had to provide CPR until a doctor declared death. Therefore, being 40 minutes out of town, we had to do a lot of chest compressions and ventilations. Listening to a dead person fart and burp is a bit disconcerting. But when he puked in the ambulance upon arrival at the ER, that was creepy. I knew the mechanics of why a dead guy would puke after 40 minutes of air being pushed into his non-repsonsive body, but still. It was as if it were his last gasp at life, from the other side of the river.


  3. leelofland

    May 14, 2009 at 10:21 am

    The third method of alteration is by adipocere formation – I believe this is what we used to call grave wax. If so, there are insects called ham beetles (clerids) that feed on this stuff.


    • D.P. Lyle, MD

      May 14, 2009 at 12:32 pm

      Just goes to show that everything is food to something–no matter how gross it is.


  4. Lise

    May 14, 2009 at 10:30 am

    Wonderful encapsulization of the various post-mortem processes!

    My only question – the cases of the “bog people”, found in the UK and in Germany (and perhaps other places) – is this a process that falls under the umbrella of mummification (just via a different environmental route – peat vs. dry air), or is it actually a fourth kind of process? I’d read a book about various cases of discovered “bog people” bodies and the food in the stomachs was still discernable, etc. I’d love to hear your thoughts!


    • D.P. Lyle, MD

      May 14, 2009 at 12:50 pm

      Bog people could be considered in the “mummy” category since they look like mummies—except even better preserved. Some even have visible scars, tattoos, and fingerprints. Where as a mummy is severely dehydrated and appears as if old leather had been stretched over a skeleton, bog people look more like clay models or something like that. They are rare but when found are usually in bogs near salt water. These waters are very acidic–from the salt and from decay of the plant material in the area and a few other sources–and the acids preserve the tissues by killing the bacteria of decay. Interestingly, these acids will often dissolve the bones yet preserve the tissues, leaving behind a eerily preserved corpse with no, or few, bones.


  5. Llyn K.

    May 14, 2009 at 11:11 am

    Hi, just discovered your blog through SinC. This looks great! I look forward to learning new things here. You mention the amount of time needed to create the adipocere formation — what about regular old putrifaction? Does that happen as fast as meat sitting out on the kitchen counter on a hot summer day, or are there things that delay it or hasten it? Does it start from the bowels and move outward, so that the skin stays relatively intact longer than the innerds? I read, by the way, that 90% of the “cells” in the human body are actually bacteria. Does that sound accurate to you?
    Looking forward to more gross information —


  6. D.P. Lyle, MD

    May 14, 2009 at 12:38 pm

    The bacteria essentially all come from within the bowel and yes the decay process goes from in to out generally speaking. And it is exactly like a meat decaying on your counter—though I suspect you’d toss it fairly early in the process. The warmer the conditions the faster they work and grow and multiply so that the body in the Louisiana swamp might be severely decayed in just 48 hours and a complete skeleton in 2 weeks, while one in Minnesota in winter will not decay until the Spring thaw. Don’t know about the number of bacterial cells in the human body but what you say is possible, I would suspect.
    If you want to know about the decay process in detail and how it is used to assess the approximate time of death, this is discussed in greta detail in two of my books: Forensics For Dummies and Howdunnit: Forensics.


    • Llyn K.

      May 14, 2009 at 1:26 pm

      Thanks for your answer. I will definitely latch onto one of your books.


  7. edith maxwell

    May 15, 2009 at 11:35 am

    I just found your site, too, through SINC. Thank you so much for sharing with us. I find it all fascinating and very information. I’m sure questions will follow!

    Edith Maxwell


  8. Sheila Connolly

    May 15, 2009 at 2:27 pm

    There are, I believe, two excellent examples of adipocere-converted bodies on public display in the Mutter Museum in Philadelphia, if you want to get up close and personal.


  9. alex

    May 22, 2009 at 10:26 am

    Thanks, interesting.


  10. shell

    June 22, 2009 at 1:23 am

    I have been following a case online, and have some questions about adipocere.
    Since it is known to occur in animals and humans, is there anyway to determine the source(human vs animal) of the adipocere if it is found in trace amounts on something seperate from the body?

    Could this trace amount of adipocere only be attributed to a decomposing human, or is it possible that it is the result of a person wiping their hands on paper towel after touching meat, and then leaving it in a sealed trash bag in hot weather ?

    Can this process only occur from a whole body decomposing at once? Or could a single limb also result in adipocere formation?


    • D.P. Lyle, MD

      June 22, 2009 at 6:27 am

      Adipocere forms by the action of certain anaerobic–don’t require oxygen–bacteria on body fat. The process is similar to soap making. It occurs most readily in cool and damp conditions. I don’t think it would happen from just wiping your hands on a towel as there wouldn’t be many fatty acids to act on. Yes, it can occur in just a portion of the body such as an arm or leg,. or the upper part ot lower part.


  11. Tulessa

    October 2, 2009 at 3:59 pm

    Just a quick question. Can bacon grease be mistaken for grave wax? Say, wiped on a paper towel?


    • D.P. Lyle, MD

      October 2, 2009 at 5:11 pm

      It’s possible at least visually–particularly if it has been there a while and has dried to a denser consistency.


      • Tulessa

        October 3, 2009 at 4:23 am

        Ok, I should have been more clear on what I was asking. In a case in Florida, the FBI determined that Grave wax was found on some paper towels in the trunk of a car. Some people have said that it could be plain ole bacon grease. Is that so? Would the FBI not know the difference? Thanks hun!


      • D.P. Lyle, MD

        October 3, 2009 at 6:07 am

        Visually they might appear similar but the lab would have no trouble distinguishing one from the other.


      • WSH

        November 10, 2009 at 3:31 pm

        1.How would they (the lab) make that determination?

        2. Are there different chemical components or reactions in human vs animal adipocere? What are they?

        3.And is bacon grease composed of different elements all together from all adipocere?

        It seems like some components of adipocere are also within the plant species, ie oleic acid. How do forensic scientists differentiate? Can they know for certain?


      • D.P. Lyle, MD

        November 10, 2009 at 8:12 pm

        Adipocere is easily recognized by the ME and the lab. It is a chemical reaction between animal fat and the acids and alkalis in the environment so it would appear the same in animals as it does in humans. This would include pigs, the source of bacon. As far as I know this reaction does not occur in plants since they do not have fat.


  12. Tulessa

    October 3, 2009 at 6:23 am

    Thank you. 🙂


  13. myserie

    October 3, 2009 at 5:28 pm

    Marvelous information source! Quick question: would there be identifiable DNA within the adipocere left at a dump site?….can adipocere be linked to any identifiable biological markers to narrow down the identification of wither the decomposed victim remins or an empty grave site? TIA


    • D.P. Lyle, MD

      October 4, 2009 at 9:03 am

      Adipocere is mostly soap—the chemical alteration of body fat to a soap-like substance—so it would have few if any cells and no DNA. There could be some cells or tissue bits from the decaying body associated with it so DNA might be available through those cells. It might not be intact and usable though.


  14. Harmony

    November 12, 2009 at 3:29 pm

    Dr. Kyle,
    I am an avid reader of forensic material. I plan on purchasing your books to further educate myself.

    It would be greatly appreciated if you could answer the following questions.

    A two year old goes missing in the middle of a hot summer in Florida. A month after she goes missing the mother’s vehicle is discovered and the trunk has a strong odor of decomposition. Inside the trunk is a trash bag with adipocere like material on some paper towels. The paper towels are infested with maggots. Butyric acid is found on the trunk carpet. Five months later the skeletal remains of the two year old are found dispersed in a swampy area. It is discovered the remains had originally been placed in two trash bags and a laundry bag but were later scattered by animals.

    Question: Would it be able to be determined if the adipocere on the paper towels came from the child since there is no DNA? Would the adipocere from a toddler be able to be distinguished from bacon or other food items?

    I look forward to reading your books and thanks in advance for your reply.


    • D.P. Lyle, MD

      November 12, 2009 at 3:47 pm

      This scenario sounds as if it is a real life case and if so for Medico-Legal reasons I do not answer such questions. If it is for a work of fiction then you can submit your question and I’ll answer it. But I require certain information before answering questions. These requirements can be found on my website under the Forensic Community tab. Supply all info and send your question directly to me and I’ll get back to you as soon as possible. Go to:


      • Harmony

        November 12, 2009 at 7:43 pm

        It is a real case. I saw that others had asked about the same scenario and I added more detail. I understand that you cannot answer. Thank you for your time and for your response.


  15. Jack

    December 9, 2009 at 9:55 am

    I find what is said about “decay starting mainly from within the bowels” to be very interesting. That makes a lot of sense to me. Having clean bowels means better health right? To say that the bowels are the Grand Central Station of the body in terms of decay and decomposition. Therefore a reverse logic of cleaning out ones bowels should well apply right.


    • D.P. Lyle, MD

      December 9, 2009 at 5:19 pm

      The bacteria that live within our GI tract are essential to our health and even life. This symbiosis is responsible for things like producing certain clotting factors in the blood, without which we would bleed severely from even minor injuries. And they do many other things. There is no known or proven health benefit from a high colonic or any other bowel cleaning procedure and they can in fact be dangerous if performed improperly or too frequently. These bacteria are mostly anaerobes—meaning they don’t need oxygen and in fact grow better without oxygen being present. So at death when the heart stops and no more oxygen reaches the gut, they go to work to begin the decay process.


  16. Patti

    December 18, 2009 at 9:31 pm

    What would happen if someone tried to clean up a crime scene with paper towels, say within 2 and a half days in a hot humid environment and the body was in the trunk of a car. Would the grave wax be detectable at that point if it was cleaned up with a paper towel?


    • D.P. Lyle, MD

      December 19, 2009 at 10:21 am

      It depends upon whether any of the material got into the trunk carpeting and nooks and crannies or not. The adipocere could be wiped onto the carpeting as the corpse was moved but if you are asking if the adipocere would melt like real wax, then the answer is not likely at the temperatures reached in the trunk of a car–even one sitting in the sun.


  17. LRCE

    December 23, 2009 at 10:33 am

    Would the freezing and thawing of a body effect the way it decomposes? I mean, besides the obvious slowing/cessation of decomp processes, once the body thawed, would decomp resume as though the body was never frozen? Or could it accelerate or retard certain processes by having excess water involved?

    Also, what about size? Is there a dramatic difference between, say, a 200-lb man vs. a 40 lb child as far as rate of decomp or do the biochemical interactions pretty much require the same amount of time regardless of size?


    • D.P. Lyle, MD

      December 23, 2009 at 3:29 pm

      Intermittent freezing would slow the decomp process. It would come to a halt with each freezing and then rev up again as the thawing began and would press on at full bore once thawing was complete. So how fast the body decayed would depend upon the amount of time spent thawed versus the amount spent frozen.


      • whatgivesq

        December 28, 2009 at 8:30 am

        Would the body decompose more quickly after freezing, since the cell walls are broken down by freezing?

        IOW, would freezing/thawing hasten the decomp, once thawed?

        Thank you for your answers


      • D.P. Lyle, MD

        December 28, 2009 at 10:43 am

        No, the freezing would not alter the rate of bacterial growth once thawing was complete. It would slow the process since the thawing takes many hours, even a day or two under certain circumstances. A frozen turkey takes a couple of days to thaw in a refrigerator–same thing here–if the frozen body were dumped in a cold area it might take days for it to thaw completely. The bacteria would become active as the various parts of the body thawed.


  18. A. Michael Schwarz

    June 3, 2013 at 4:47 pm

    Question for the expert: how long would it take to thaw a corpse from a morgue, deep freeze? Is there a way to speed the process up, like by soaking it in warm water?




    • D.P. Lyle, MD

      June 3, 2013 at 6:23 pm

      Andy–I don’t answer questions her as I require certain information before doing so. Visit my website and you will find instructions for submitting questions.



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