Refractometer Reading is 22%

Beekeeping & Apiculture Forum

Help Support Beekeeping & Apiculture Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


New Bee
Aug 27, 2009
Reaction score
Hive Type
Number of Hives
Have just but a refractometer and tried it out on a bucket of honey. I've marked the bucket as uncapped rape - which I initially tested by shaking the combs for loose nectar. After warming the honey the refractometer reading is about 22% water. I've used it as it came on factory settings.

Having had a batch of rape ferment last year, I'm now a bit wary about jarring before making sure it's ok.

So is 22% water ok? Or will it ferment - on a visual level it looks ok - no bubbles?


I am very surprised, if it is OSR honey, that it has not granulated already, unless perhaps spring sown rape. Is that the case and you have warmed it to liquify some of the honey, followed by a test on that sample?

If so, you will get erroneous results as the whole bucket will not be homogenous.

Refractometers are calibrated at a particular temperature, so not knowing the type, one cannot comment on the result's accuracy.

You can buy standard samples for checking the calibration.

You can make your own, even if you do not know the water content, if you have the appropriate equipment.

If you have granulated honey, you will see very quicky if there is a fermentation risk. The suface will not be dry.

I doubt, at 22%, you are safe to bottle it although IIRC I have seen nearly 23% in a honey spec. You need to check the Trading Standard specifications.

Hope this helps.

Regards, RAB
You need a Reference Block & Oil to reset it.
Don't know where to buy one.
I got one with my refractometer.

Assuming you are testing at about room temperature then I suspect the reading should be accurate. From the above table the difference is only half a percent at most. My refractometer came with a block and some oil but it needed no adjustment. You could always try it against some honey form the supermarket. If it comes out at about 18% then this would be an additional guide that your refractometer is fine. Different honeys vary of course but unless it is heather honey it will should have a reading less than 20%.

At 22% your honey is likely to ferment I fear. My solution in the same circumstances is to leave the honey in buckets without lids in a small room with a domestic dehumdifier running. The moisture content goes down by about 0.5% per day with my set up. I have not found it necessary to stir the honey but you could if you felt more comforatable.
My solution to too high water content?

Let the bees reprocess it. A bit late in the season, perhaps, you might be thinking.


Presumably these buckets are covered with something?

honey form the supermarket

Don't rely on it. Remember, pasteurised honey should not ferment and water makes more profit than honey, so the big boys who are blending will be selecting which to blend! Would't you?

Are these full 10l (mine might be in 5,10, 15, 20, or 25l!) plastic buckets? What temperatures are you running in this room?

Regards, RAB
Members I think you will find that the maximum water content is 20% and not higher for bottling honey. That's from memory but I could bee wrong. I'll check it out.

BBKA have an information sheet regarding selling honey.

To answer RAB's questions: The buckets are uncovered but it is a clean room where I do my bottling - no ants or flies etc. The temperature doesn't get much above about 24 or 25C. If someone wasn't sure of the cleanliness of their room then I would suggest they put some cloth over the buckets. I don't think it would slow down the process to much although I haven't tried it.
I would be inclined to check the calibration of the refractometer, did you buy the instrument from eBay, most suppliers offer the oil for their refractometer as a purchase option.

Regards selling at 22%, check what Campbell's Honey in Canada has to say about the multinationals, see ...

However, I would want to see my honey below 20% before selling it, ideally at around 17%.
Thanks for the advice - comprehensive.

Yes I had warmed the honey (was set like stone) for creaming - I did wonder if I should have taken the reading after creaming - ie. well mixed. It was only partially molten at this point.

It did have a dry surface. I did shake each comb thoroughly before harvesting, and left any with loose nectar for the bees.

I once read that heather honey can have a higher water content between crystals - could this be the same for rape too?

It's a nuisance this rape isn't it? But good flows.