Author’s bee yard alongside canola field. Honey produced here granulates quickly.
The American Bee Journal published a timely piece in their August issue. It just hit my mailbox. The article is about avoiding granulated honey in your extracting frames. It’s written by your favourite bee-blogger. Me.
I’m not going to repeat my article here because you can read the whole thing in the bee journal. If you don’t already subscribe to the ABJ, you should. It’s a great resource for beekeeping and bee science. You can see my article in the magazine, but I will paraphrase part of it because it’s an important topic.
Trouble: granulated comb
Granulation can be a big expensive problem for some beekeepers, but others never see combs of crystallized honey. Along north Florida’s Apalachicola River, beekeepers produce tupelo honey which almost never granulates. But in northern, dry regions of the plains and prairies, canola honey may crystallize in the hive a week after bees store it.
Most honey is between the extremes of canola and tupelo, crystallizing a few months after extracting. The primary causes of granulation are the honey’s glucose-to-moisture ratio, storage temperature, the passage of time, and purity of the honey. I cover these in detail in the American Bee Journal. Today, I will just give a summary of two points – moisture and glucose.
High-glucose honey – safely in a jar.
There are two main sugars in honey – fructose and glucose. They vary between species of honey plants. It’s the glucose that forms crystals. Just a little more glucose makes a big difference in granulation. Floral varieties high in glucose include canola, cotton, mesquite, and manzanita. Those with low glucose levels include tupelo, acacia (black locust), and sourwood. The low ones are slow to granulate.
Water is also important in this discussion. Think of honey as an unstable, supersaturated solution of just glucose and water. Glucose crystals precipitate if there is about one-and-a-half times more glucose than water in the honey. In other words, if your honey is 18% water, then 27% glucose is the cut-off. Very few types of honey have such low amounts of glucose. Average American honey is 31% glucose. Canola averages 36% while tupelo is just 25.6%. These numbers are similar in other parts of the world – most honey has enough glucose to crystallize if moisture is below 19%. (Honey over 19% is less likely to granulate, but it will sour and ferment.)
Here’s how this relates to your honey crop. You probably can’t avoid areas or crops with higher contents of glucose. You probably don’t want to – maybe that’s where you make most of your honey. But if you are in such an area, get the honey off the bees quickly (as long as it’s ‘cured’ or ‘ripe’ enough and below 18.6% water content. Then keep the boxes warm – combs granulate most rapidly at about 15 ºC (60 ºF). Finally, extract as quickly as possible – don’t let the boxes sit around for weeks, but get at ’em and get ’em done!
There is more to this story. Temperature and timeliness are important. And there’s something I call ‘purity’ in my article. This involves avoiding dust and old granulation crystals in the honey frames. These serve as starting points for new granulation. These things (and more) are included in my American Bee Journal piece. The bottom line is keep things clean and warm and get things done on time – the same advice you’d hear from any beekeeper.
Which honey will granulate? Those at the top of the graph are most likely to crystallize because of their higher glucose level. Moisture varies with region and local climate, lower moisture honey granulates more quickly than higher moisture honey.
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Congrats on your article. How do you recommend keeping the boxes warm and what would be the ideal temperature to keep them at?
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Hi!
Keeping the boxes warm is two-fold. First, if you can get them off the hives as soon as the honey is ready, the honey will retain some hive heat. (Some beekeepers have 5, 6, or more boxes stacked above the brood nest – the top boxes may become rather cold late in the fall. This can be a problem.) When the ‘warm’ supers are brought in, it’s easier to keep them warm.
Second, most beekeepers here (Canada) park their full supers in a hot room before extracting. This is an insulated space where a furnace (or radiant natural gas tubes, or heated water in the floor) keep the boxes at about 100ºF (38ºC) until extracting. It’s easier to keep the boxes warm than re-heat cold ones. Finally, of course, extracting as soon as possible is always smart.
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Thanks Ron. Not encountered the 5 or 6 supers problem here in London! Occasionally I have seen a hive with 3 supers on. Are these commercial beekeepers who have the special hot rooms, surely a hobby beekeeper wouldn’t have one?
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Hello Ron! Thank you for the very informative article. I did have some frames like this today as we were harvesting our honey and wasn’t sure what the problem was. They are ceryainly some “crystals” now in the mix of our several gallons that are sitting to be final filtered (200 micron). With these frames I did not return them to the house. I set them outside of the hive for the bees to clean. Will this be problematic in that they may bring in some of those crystals back to the hive? Thank you in advance for your response! Deb K.
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Hi,
I don’t think that the bees will carry granulation crystals back to the hive while cleaning the frames. Most likely all the ‘wet’ honey will be robbed and any crystals will be left behind in the combs. The trick is to get the honey cleaned out before the first crystals form. You likely already know about risks of setting frames out in the open to be robbed – if any disease is present, it can be carried or given to other bees in the neighbourhood; and, once bees begin to rob, they sometimes get pretty caught up in the excitement and start to fight or rob weaker hives that may be nearby. Sometimes beekeepers put the frames to be robbed inside a box stacked back on the hive so just the hive they came from can get at the sticky frames.
In another note, you mentioned you have alfalfa, sweet clover, and locust – those all make nice quality honeys and are usually slow to granulate. But given time and low humidity, almost all honey does eventually set up. Good luck with your bees and thanks for reading the blog!
Ron
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Hi Ron,
Your article is food for thought!
We live in a very dry area and never had honey granulating in the frames until last year, which was unusually humid (El Niño). This seemed a contradiction, until I realised the reason: the wild flora – the main origin of our honey – had changed according to the increase in humidity, so our bees had foraged on different species. Nature never ceases to amaze me!
How about returning those partially crystallised frames to the hive? Will the bees use crystallised honey as a source of energy? Or rather, will that honey become fluid again at hive temperatures..?
Thank you!
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Hi Graciela,
Thanks for the interesting perspective – usually humidity increases moisture in honey, thus reducing granulation speed, yet you ended up with granulation in a wet year! I think you’re right – even a minor switch in forage plants can shift fructose/glucose levels and change chances of crystallization.
If your bees are hungry, they will certainly clean out most of the granulation and use it as energy. They won’t usually store Xlz’d honey in combs after eating it – they’ll usually just eat it as they need feed. Also, I don’t think the honey will become fluid again at hive temperatures, though with the mild hive-heat, it will soften a little and be easier for the bees to eat.
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Thanks for the comment!
I hope people don’t think that crystallization is entirely due to temperature change – it’s a component, but I think that the strongest correlation is with glucose/moisture ratio. Honey that’s high in fructose is slow to granulate, but glucose-rich honey on a chilly night in a dry climate (the moisture level is lower, making a more saturated solution) may turn hard in days. If I had to rank the qualities, I’d go glucose percent, temperature, honey moisture, and fine grains (dust, pollen, previous granulation nuclei) – in that order of importance.
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