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In a previous post, I discussed why grocery store honey often tastes bland and boring. I mentioned floral sources, mixing, and filtering. But one important issue I didn’t mention is pasteurization. Unless it’s specifically marked “raw,” much of the honey on grocery store shelves is pasteurized at some level.
Most of my sources claim that honey is pasteurized to “kill bacteria and yeast, or to reduce crystallization.” Now we all know that honey is famed for its antibacterial properties, that it is still used to dress wounds, and that it can keep for years on end. So why, exactly, do we need to worry about bacteria?
What is pasteurization?
Pasteurization is a process that destroys microorganisms with heat. Different combinations of temperature and time can be used to pasteurize, depending on the substance. Most references I found recommended heating honey to 145° F (63° C) for 30 minutes. Some preferred 150° (65.5° C) for 30 minutes. One suggested that the temperature be brought to 170° F (77° C) momentarily.
It is widely stated that very young children or those with compromised immune systems should consume only pasteurized honey. The reason? There are a small number of cases each year where spores of Clostridium botulinum found in honey have germinated and caused botulism poisoning.
According to the U.S. National Library of Medicine, approximately 110 cases of botulism poisoning occur each year in the United States, mostly from improperly canned food, corn syrup, and honey. About 90% of these cases occur in children under six months old.
Why does botulism in honey affect only children?
Although the spores of Clostridium botulinum cannot grow, reproduce, or make toxin in the acidic environment of honey, they survive in a resting state. But if the spores are eaten by an infant, the spores can grow, reproduce, and make toxins while living in the baby’s intestinal tract.
This occurs because a baby’s digestive system is not mature enough to resist the bacteria. Instead, the bacteria develop until they can release the toxins. The toxins are then absorbed into the child’s body and can cause illness.
Fortunately, children lose the ability to grow the bacteria in their gut by the time they are about six months old. Adults with compromised immune systems may never be able to neutralize the bacteria.
Botulism spores are resistant to standard methods of honey pasteurization
So here’s the catch: pasteurization of honey as it’s normally practiced will do nothing to prevent botulism in infants or in immunocompromised adults.
Both the actual Clostridium botulinum bacteria and the toxins it produces are easily destroyed by boiling for several minutes or by holding them at lower temperatures for longer times. The spores, on the other hand, are extremely resistant. Pressure cooking at 250° F (121° C) for three minutes will kill the spores, as will other combinations of temperature, pressure, time, and acidity. But at standard pressures, it could take hours of boiling to kill them.
As I showed you above, the common honey pasteurization process is much less rigorous and could not possibly kill the spores. However, any of these levels of heat will destroy the nuanced flavors of honey as well as many of the phytochemicals, antioxidants, and nutrients. In other words, we are destroying the best qualities of honey but receiving no benefit.
To be totally safe, young children and those with compromised immune systems should not eat honey. Period. Unless you know specifically the time and temperatures used for the pasteurization process, I wouldn’t chance it.
If it doesn’t kill spores, why do we pasteurize honey at all?
Good question. Honey is pasteurized to make life easier for the people bottling and marketing honey. They may be individual beekeepers, but most likely they are large distributors who buy honey, process, bottle, and redistribute it.
In truth, honey is less likely to crystallize once it is pasteurized, and liquid honey is easier to sell. So it makes sense from a storage, distribution, and marketing perspective to keep it liquid as long as possible.
Pasteurization does little or nothing to help the consumer. After all, the added heat destroys many aspects of taste and nutrition, while it fails to kill botulism spores in most cases.
Unfortunately, people call unpasteurized honey “raw.” This makes it sound like it’s “uncooked” or perhaps “unready” for consumption. Nothing could be further from the truth.
We need more education, not more processing
Most honey already carries a label warning the consumer not to feed it to infants. Couldn’t we extend that warning to include individuals with compromised immune systems and leave it at that?
It’s no wonder that honey is not more popular. We remove the enchantment. After cooking away the flavor, we are left with nothing but sticky sweetness. What is the point of ruining a magical product for so little—or no—benefit?
Honey Bee Suite
I like your perspective!
Do you think that besides straining, the only additional procedure (that might be) required in the processing of honey is the reduction of moisture? Johannsmeier (2001) states that honey with less than 17% moisture content is safe (will not ferment) regardless the yeast content. My idea is to find a honey moisture evaporator (that works at ambient temperature) to reduce the moisture content to 17% and like you suggest add warnings for consumers not to feed honey to infants and individuals with compromised immune systems.
If the honey has been capped, it is safe to assume it is dry enough not to ferment. But it you are adding uncapped honey to capped honey, then you would want to test for moisture and dry it down, if necessary.
Good article on bacteria, but pasteurizing is done to kill yeast, just thought you should know so you can update your article.
Pasteurization can be used to kill mold and fungus, but pasteurization of food products can also kill the organisms that cause tuberculosis, brucellosis, diphtheria, scarlet fever, and Q-fever; it also kills other harmful bacteria such as Salmonella, Listeria, Yersinia, Campylobacter, Staphylococcus aureus, and Escherichia coli. Any intro level book on microbiology will help you with this concept.
Yes, but honey in specific is not pasteurized because they want to kill bacteria, it is pasteurized to kill the yeast.
Yeast will not grow in honey if the water content is at the proper level. Yeast will grow if the water content is too high, or when crystallization leaves the uncrystallized part too watery. Heat destroys certain elements of honey and should be avoided in order to preserve the best flavor and the most healthful properties. One way to handle honey that will crystallize quickly would be to “cream” it using the Dice process.
We harvested 1 ton of honey in the Lowveld of South Africa and ensured that it was 99% capped. The average temperature was 38 degrees celsius and the average humidity 127%. The honey moisture content was 18.5% so I presume the honey (being hygroscopic) absorbed moisture from the air. How do you suggest reducing the moisture content?
Moisture at 18.5% is nearly ideal. I would just leave it. Check locally, but in the UK, for example, honey can be sold with moisture up to 20%.
FYI: Milk is pasteurized at 145 degrees for 30 minutes, or 161 degrees for 15 seconds. Cream on the other hand must be heated 5 degrees higher in both these time frames, 150 degrees for 30 minutes and 166 degrees (or 170) for 15 seconds. It is because of the thickness of the extra fat molecules in the cream, which makes sense that the thicker honey would require the same increase in temp. Good article !
Pasteurized “honey” should not be called honey. It is a shame that this product can be sold in grocery stores, with the label honey, as in fact it isn’t honey anymore. The taste and all health benefits of REAL honey are wasted in the pasteurization process. Instead you should buy honey from your local (preferably) biological beekeeper, who doesn’t use chemicals and practices beekeeping in a natural and bee-friendly way, and harvests honey without heating (= wasting) it.
Sealed honeycombs guarantee the moisture percentage is below 20%; industrial honey is often harvested too early and therefore needs to be heated.
Uhh…no they aren’t.
Rusty and Guy, you are both right. Honey is a natural anti-bacterial and it’s a very harsh environment for bacteria to even try to thrive in. You do have to worry about yeast. They pasteurize honey to eliminate the risk of fermentation. It also doesn’t crystallize as fast, making a more appealing consumer product. Certain types of yeast can pose health risks to people with compromised immune systems like you mentioned. For example Aspergillus is yeast that can cause some nasty disease in humans and animals (think lungs if you open honey with it and breath it in). I for one would not want to eat honey with Aspergillus. Aspergillus produces alfatoxins which when the body metabolizes passes through the liver. It can cause liver cirrhosis and acute hepatic failure.
You probably have a better set of data for this, please do feel free to help me get the numbers right. Specifically the state’s definition of ‘heated’ has a temperature associated with it… somewhere? 🙂
Check your state, province or other regulatory agencies for details for your own area. I would expect that most will have something similar to what Washington State has on the books.
Washington State has exempted beekeeper extracted honey from the requirements of a Food Processing License as long as it is ‘raw:’ “Beekeepers who extract their own honey can sell it in the raw form to the end consumer…” (See the first link below)
If the honey is heated, spun, etc. the license is required. I have seen somewhere, the definition of ‘heated’ in this context. I cannot, however, find the official text to back it up. I *believe* that the temperature was 120 degrees (F) but, as stated I, can neither confirm nor deny this part is indeed a FACT.
This could be a consideration for any plans for pasteurizing, heating to reduce moisture content and so forth.
I don’t know of anything that would prevent a seller to offer a handout with recipes and either a ‘How-To’ or a link to where information on ‘Pasteurizing at Home’ might be found.
Happy New Year all. 🙂
Excellent article! I love honey very much. I would say I am married with honey from my early childhood time. Fortunately in New Zealand the honey is most time in its natural form – raw. I was thinking about the moisture content in honey you guys were discussing above. I know one good method I am using in my job ( I am industrial electrician). It is a “dry air”. In industry I am working for we extract the moisture from the oils by applying vacuum and then filling up the empty space with the dry air. The oil could be mechanically processed to expose all moisture to the dry air to speed up the process (or flashing with the dry air). This process does not strictly require the vacuuming but I am pretty sure that i could be an idea for removing access of moisture from honey. It is not too expensive to equip itself with a dry air compressor .
Interesting. I have never heard of a dry air compressor.
I make my own honey syrup to add to cold tea (honey and water mixture) so I actually need to kill the yeast so it doesn’t ferment in my refrigerator. I usually purchase raw honey, would I need to pasturize it myself by boiling it for 30 minutes, would that be long enough to kill the yeast?
Sure, I have no doubt that boiling honey for 30 minutes will kill the yeast. It will also ruin many of the flavor components, weaken the aroma, and destroy many of the healthful properties including some of the antioxidants, phytochemicals, and nutrients that define honey. Plus, you no longer have raw honey, you have cooked honey.
Also, even though you kill the yeast, next time you open the container, yeast in the air will recontaminate it. So just make an amount you can use up within a week or so.
You pasteurize honey when using as an adjunct in brewing beer. You want the honey flavor but not the yeast to fight with the specific beer yeast the brewer has worked to keep sanitized. Wild yeast and bacteria ruin beer.
Good to know.
A little off topic here, but I haven’t been able to find any information about this. I bought some kosher honey the other day and it’s listed as being “pure honey “.
Is kosher honey pasteurized ?
If I understand correctly, kosher honey is not pasteurized but is pure and raw.
Thanks Rusty. Another question here…does pasteurized honey crystallize slower than honey that is not pasteurized?
Some people say so. But it is more a matter of the ratio of glucose to fructose in the nectar, so it varies by plant. Some things like canola, crystallize very fast. Others, like tupelo, hardly ever crystallize.
Hi Rusty, I bought manuka honey from New Zealand and it’s listed as “100% pure honey”.
Is manuka honey pasteurized? And is it safe for pregnant woman? Please help.
I’m afraid I can’t help you. Manuka is the name of the plant where the nectar was gathered to make the honey. Whether or not the beekeeper pasteurized it, I would have no idea. If it doesn’t say pasteurized, I would assume it’s not, but you can’t be sure. Honey can be 100% pure and be pasteurized or not.
I’ve never heard that honey is not safe for pregnant women, but I’m not a doctor. If you have a question about the foods you should or should not eat while pregnant, you should ask a doctor or perhaps a dietician.
I’m in the middle of processing some honey from my topbar hive, and I noticed that some of the comb and honey came in contact with some small clods of dirt in the bottom of the hive box. I’ll screen these out, but I’m tempted to pasteurize since it has come in contact with dirt, which I’m can’t be a good thing. Any thoughts from anybody?
Any pathogens that may have been in the dirt cannot live or reproduce in honey, which is highly hygroscopic. Just filter out the particles for aesthetic reasons and you’re good to go . . . better, I think, than pasteurization which doesn’t do much of anything. That is why honey is used on burns: pathogens cannot live in it.
Great article and discussion. Informative
The farm that I bought the honey from, informed me it is not pasteurized but filtered twice. What’s the difference?
Pasteurization is done with heat. Filtration is done with a fine mesh strainer. Filtration gives a much better product.