Honey is about 80% sugar and 18% water. The rest is minerals and ash*, pollen grains and bees’ wings. The sugars and water come from nectar secreted by flowers. When flowers produce nectar (as a way of attracting pollinating insects and birds), it is very watery – maybe 20 to 90 percent water. (This varies a lot.) So bees may carry three or four or even ten pounds of nectar for each pound of honey they produce.
The bees remove water so that honey will be safe to store without fermenting into honey wine. Fermented honey would not last long in a crowded hive because the bees would drink it all in one evening of intoxicated merry-making. That would really put the ‘waggle’ in their famous waggle-dance.
For honey to be stable, the nectar needs evaporated until less than about 18.6% of honey is water. I’m not sure if anyone has figured out how the bees know this number. My hunch is that honey bees don’t actually know. They haven’t perfected their hygrometric skills – we sometimes find honey in the comb that’s been sealed and is not quite stable. In time, it can begin to sour or ferment. That’s really rare, but it can happen, so it points to some design flaw in the bees.
Last month, a friend brought some bottled honey to my home. It came from sealed frames. Surprisingly, it tested over 20% moisture. High-moisture honey is rare in western Canada, but my friend’s bees had been in a heavily wooded spot with poor air drainage. I told him that he had a few choices. He could deep-freeze it, then take out a little at a time and use it quickly. He could cook it until the honey’s yeasts died, but that would darken the honey and give it a burnt flavour. He could possibly feed it back to his own bees, if all the hives were AFB-free. Or he could make wine.
A few days ago, another beekeeper brought honey to me for testing with our bee club’s refractometer. Her honey was still in the comb. Nearly all of it was low-moisture, some all the way down to 16%. But there were also a few frames of unsealed honey – it looked watery. Some of that watery honey approached 21% moisture. Fortunately, there was just a little which was that high. The highest-moisture honey was on the lightest, unfinished frames. The honey flow had ended days ago, so I was surprised that the bees hadn’t dried it out yet. But they had not and she’d removed the honey frames. Since there was so much dry honey (maybe 100 pounds) and so little wet honey (maybe 3 pounds), I did the math and told her to extract it all at one time and let it mix together. [Here’s the math: 100 pounds at 16.5% mixed with 3 pounds at 21% is 16.5 + .63 pounds of water in 103 pounds of honey, making it a very safe 16.7% – if well mixed during extracting.]
To mix the trivial amount of higher moisture honey with the thicker honey during extracting, it would make sense to stagger frames in the extractor and not do all the wet ones separately. I was really surprised that on one frame which we’d tested, the open cells were 20.5% moisture and the sealed honey, just inches away, was 16.2%. You could tell immediately that there would be a big difference – the sealed honey was very thick and sticky while the open honey was quite wet. (It takes only a surprisingly small percentage to go from watery to thick.)
During the nectar flow, you can get very watery nectar in cells right next to dry honey, but we were looking at the frames days after the flow had ended. On this particular frame, I think the small patch of sealed honey was made earlier in the season – it had a darker hue and slightly different flavour than the newer, wetter honey. Nevertheless, I was surprised by such a large difference in moisture in honey on the same frame, well past the end of the season.
(*) An astute reader has pointed out that it’s not really ash, but the burnt residue of the honey following chemical analysis. See the comments below.