Honey apparently does not naturally decompose. Why?

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I heard that honey doesn't decompose. I've also heard this about peanut butter. Would they decompose if mixed?

What stops these from decomposing?

I'd expect that any high energy molecule would eventually react into some lower energy state, regardless of whether microbes are involved.

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  • #2
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Here decomposition is related to bacterial decomposition. Bacteria do not grow in honey, peanut butter, and other like substances because these substances have a very low water content and will actually dehydrate any bacteria that lands in the substance. These substances can still decompose chemically, but at room temperature, any chemical decomposition occurs very slowly.

See the related PF thread here: https://www.physicsforums.com/showthread.php?t=615560
  • #3

Low water content is definitely a major factor. Fresh meat and fish require cooling (which slows down all biological and, to a lesser degree, chemical processes) to last more than a few days at most. Dried, however, they can last for a much much longer time.

Another, probably less important, factor is that honey contains natural antibiotics. There are a few other foodstuffs which do, and presumably all of those keep for a comparatively long time.

Off the top of my head, I can name cocoa and garlic. Cocoa is a seed, and those are naturally more resistant to all kinds of decomposition - they need to be, to fulfill their function. Garlic works well to illustrate this, though. Its water content is, at first, not particularly low, and yet, when stored under appropriate conditions, it desiccates to the point of crumbling to dust before ever becoming moldy.
  • #4

What about flour or rice? Both seem very low in water, but I've had meal moth caterpillars growing in these. The difference I can think of is that the moth caterpillars do not feed via diffusion. They physically bite/chew off whatever they consume. This means that low water concentration will not block nutrient entry, as it does with microbes.

Has anyone had problems with mold/bacteria on their grains?
  • #5

The difference I can think of is that the moth caterpillars do not feed via diffusion. They physically bite/chew off whatever they consume. This means that low water concentration will not block nutrient entry, as it does with microbes.
The way I understand it, it's being immersed in the honey (or whatever), rather than trying to eat the honey, that's already harmful to the bacteria. Macroscopic organisms can eat the honey without immersing themselves in it - and even if they do become immersed, it's only a relatively small number of cells which are directly in contact with the substance; most are protected simply by not being surface cells. Furthermore, surface cells are specifically designed to withstand that kind of thing, so there may not be any damage to those anyway.

ps: Of course, if an insect does fall into honey, it usually will die, so the end result is the same as that for the bacterium. But that's due to drowning, which is something else altogether. :)
  • #6
jim mcnamara

pa5tabear - does decomposition include include being consumed by larger forms of life, like insects? I would say 'no'.

The bugs came from the fact that flour and other grains and ground grains have a few insect eggs scattered around. For example see:


What this means is that most grain products have the potential for bugs to show up sooner or later when stored dry and at room temperature and sealed against intrusion by insects, fungi, and bacteria.

As other posters mentioned, bacteria and fungi are the primary food decomposers.
Adding large amounts of table salt to food or dehydrating food generally slows these guys down, as does freezing and (to a lesser extent) refrigeration.

This is the reason for food companies irradiating food. All of the bacteria, fungi, insect eggs, etc., are killed by radiation. This makes the food shelf stable for very long periods of time because the food is in effect sterilized.

Let's not off the deep end on the safety of irradiated foodstuffs. This thread is not about that.

Decomposition, contamination, and waste of stored foods is a huge problem. See:

(Chapter 3 starts with a graph in this publication)
  • #7
Hmmmmnnn... interesting. Honey is essentially plant pollen and nectars. That's what the bees go and collect. Pollen and Nectar, and that is what goes into honey.

The pollens are probably acting as a preservative, anti-bacterial, anti-oxidant, etc...

The bee larvae are fed something called bee bread, and that is what bee pollen is, after it is eaten by the bees, and then regurgitated back up. It is very sour tasting, and tart, and the only other flavor I can compare it with is children's candy.

I wish I had more info at a molecular level, but I don't.

Bees have other interesting products. Propolis. They collect tree resins, and they use the resins to seal off areas of the hive that have been infected with fungus and bacterias and insects. Tree resin is essentially a trees immuno defense system and the bees know how to utilize that.

Another thing is that the bee produce royal jelly and that is fed to a normal bee, which then becomes a super queen bee. They are fed nothing except the royal jelly.

This source attempts to describe the various stages of food production, and they mention that the bees seal the nectar that is converted to honey via regurgitation with wax.


I will argue that pure honey, will probably go bad over time. The Smithsonian mentions that it will spoil once water gets into it.


I am going to guess there is probably some pollen acting as a preservative as well. That is only a guess, and I could be wrong, but natural honey, is loaded with "particulates".


Pollen can be incorporated into the honey produced in a beehive in a number of ways. When a honeybee lands on a flower in search of nectar, some of the flower's pollen is dislodged and falls into the nectar that is sucked up by the bee and stored in her stomach. At the same time, other pollen grains often attach themselves to the hairs, legs, antenna, and even the eyes of visiting bees. Later, some of the pollen that was sucked into her stomach with the nectar will be regurgitated with the collected nectar and deposited into open comb cells of the hive. While still in the hive the same honeybee might groom her body in an effort to remove entangled pollen on her hairs. During that process pollen can fall into open comb cells or the pollen can fall onto areas of the hive where other bees may track it into regions of the hive where unripe honey is still exposed in open comb cells. Some worker bees also collect pollen for the hive. The smooth, slightly concave, outer surfaces of the hind tibia in worker bees are fringed with long hairs that curve over the tibia surface to form a hollow area. This hollow area is called the "pollen basket" or orbicular. The worker bees collect pollen with their front and middle legs and then deposit it in their cubicula (Snodgrass and Erickson 1992). In the process of depositing collected pollen into special comb cells some of it can fall into the hive or into open honeycombs. It is also noted that occasionally worker bees might add pollen to the nectar they are transforming into honey.

Airborne pollen is another potential source of pollen in honey. Many types of airborne pollen produced mostly by wind-pollinated plants that are not usually visited by honeybees can enter a hive on wind currents. These airborne pollen grains are usually few in number, when compared to the pollen carried into the hive by worker bees, nevertheless, those pollen types regularly enter a hive on air currents and can settle out in areas where open comb cells are being filled with nectar. Sometimes airborne pollen is deposited into ripened honey when it is being removed from a hive by the beekeeper. Although the pollen rain for various regions consists mainly of airborne pollen, and those data are often used in forensics, archaeology, and ecology to identify a specific geographic region, those pollen data are not always as useful in melissopalynology because they generally form only a minor (?) fraction of the total pollen spectrum found in a honey sample.
  • #8
Honey is not thought to ever go bad, when stored properly. They found some in an ancient Egyptian tomb and it was still partially liquid and seemed just fine.

Quote: "They had hit the jackpot; one of the most amazing discoveries up until this point in Egypt. Apparently, even though there seems to have been cracks in all the sealed barriers, the tomb was so devoid of atmosphere that silver was still bright and shinny, but within three days of the tombs opening had it had turned black. Some vessels that were uncorked by the archaeologists still contained thick oil, and honey that was almost liquid but still preserved it scent after thousands of years."

Source: http://www.touregypt.net/featurestories/yuyat.htm
  • #9
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There almost certainly is some pollen in the honey in the hive. But bottled honey has been warmed and allowed to stand, and the particulates rise to the surface as a scum which is scraped off and discarded.

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