Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Honey and Spoilage
Name: George A. J.
Status: other
Age: old
Location: N/A
Country: N/A
Date: 2/19/2003 - Up-dated Fall 2009

I have been told that raw honey will never spoil because it is hydroscopic. Yet, there apparently is no such word as hydroscopic. There is hygroscopic, the tendency to absorb water.

Therefore, why does raw honey not spoil? What chemical properties does it contain that prevents spoilage?

Hydroscopic refers to using lenses in photography under water. Hygroscopic deals with absorbing moisture.

The nectar brought to the hive by the bees is about 60% water. The bees "cure" it to about 18-19% water. At this level of water and with a pH of 3-4, the honey is very stable and can last for literally centuries. (It was found in Egyptian tombs.) However, it is - as you mention - hydroscopic. (I believe there is such a word.) If it is left exposed to the air, it will absorb water from the air. The greater concentration of water allows yeast (that is found naturally in the environment) to multiply. A by product of the yeast is alcohol - the honey ferments. If the correct yeast is present (and naturally occurring yeast is not such) is produces a drink known as mead. If allowed to ferment naturally, honey develops an unpalatable taste... though it is still sometimes used in baking where the alcohol is evaporated from the honey.

The bees prevent the fermentation of the honey by sealing the honey in the honey comb. When we harvest the honey, we can leave it in the comb or extract it and seal it in jars, like the shelves of your local grocery store.

Because honey is hygroscopic, it is extends the shelf-life of baked goods. They are less likely to dry out because the honey absorbs moisture from the surrounding air. If you want to try this out, bake a batch of cookies using sugar. Then make a second batch replacing half of the sugar with honey. To do this you need to reduce the liquids in the recipe by 1/4 cup for each cup of honey (because of the water in the honey... remember, about 19%) and reduce the cooking temperature by 25 degrees. See which batch survives longer.

If you are interested in knowing more, check out -

Larry Krengel =================================================== George,

Right you are -- the word is hygroscopic. Nevertheless, that is only part of the story regarding honey's ability to resist spoilage. The high concentration of sugar in honey -- and its attractiveness to moisture -- makes honey (raw or otherwise) a kind of dehydrating agent. Molds and bacteria that land on the honey lose their own moisture to the honey, Thus their growth cycle is compromised and spoilage is reduced.

ProfHoff 569

I do not know why honey does not spoil -- good question -- but there is a technical word "hygroscopic".

Vince Calder

Raw honey can ferment. See this site for some further details.

J. Elliott

Dear George,

I am not a honey expert in any way but I will hazard a guess and hope that if a biologist sees this question, you will get another answer as well. I have never had honey go bad. I have had it crystallize and have to heat it to get it liquid again. I would imagine that because honey is mainly sugar, it will not spoil just like granulated sugar does not spoil. It might get hard or lumpy, but not moldy or rancid. Perhaps because it is a complex carbohydrate the bacteria in the air cannot process it.

Anyway that is an answer from a physics person.

Martha Croll

Click here to return to the General Topics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory