Although I no longer keep bees I still take an interest in beekeeping issues and I still have plenty of honey left from my beekeeping days.  I recently took a jar from my stash in the garage and saw that it had granulated (crystallised) heavily.  The best before end date was 2015.

Heavily granulated honey

Heavily granulated honey

The usual advice to deal with this on granulation advice labels  – including on labels I supply – is to use a microwave or warm water to return the honey to a liquid.

I decided to investigate these options by experimenting with two jars of solid honey both starting from the same state.


The first method I investigated was the use of the microwave oven.  I know that these work by exciting the molecules of liquid in whatever is placed into the oven.

Set my 900w microwave oven to half power.

Placed the jar of solid honey, without its lid, in the microwave and ran the microwave for 15 seconds.  After the first 15 seconds there was almost no change but I tried to stir.  I then repeated the sequence until the jar had been given 20 fifteen second bursts, totalling five minutes of microwaving with a stir between each burst. I checked the temperature of the honey, near the top edge of the jar where it was getting hottest, the temperature approached but did not exceed 60C.   Decided to stop after the twenty bursts, I did not want to spoil the honey.

Honey after microwaving

After microwave


For the second jar I used a hot water method I have seen described where the jar is put into a pan and water is added until the water level is just below the thread of the jar.  The jar is then removed from the pan and the water is brought to a simmer on the hob.  The pan is removed from the heat and allowed to cool for a couple of minutes – we are putting a glass jar into hot water with a risk of shattering.  The jar is returned to pan and left until the water has become lukewarm.  The jar was removed from the pan and stirred, the water brought back to a simmer, removed from the heat, allowed to cools and the jar returned.  I did this for a total of four times.

Honey after water heating

After water heating


Both methods worked.  The microwave method was harder to control and required my attention through the complete process.  When I decided to call a halt there were a few large granules which settled to the bottom of the jar and the honey darkened considerably.  The water method was easier to control, I put the pan lid on and left the jar as the water cooled.  A few small granules eventually settled to the bottom of the jar and the honey was lighter in colour than the microwaved honey.


I would not use the microwave method in future as I would be concerned about spoiling the honey.  For the same reason I would also not recommend it, it needs careful monitoring.  How would you explain that to a customer?


As a result of this experienced I have introduced granulation advice labels which just describe a form of the hot water method.  Labels with both methods are still available from me. I have also revised the wording on my granulation advice labels and made the labels smaller.  There are now 32 labels each measuring 48mm by 34mm to a sheet which is better value for my customers.



At what temperature does honey have to be heated too, too destroy the health benefits for humans? (sic) not my typo.

Don’t wreck your honey!

How to decrystalize honey.

Microwave processing of honey negatively affects honey antibacterial activity by inactivation of bee-derived glucose oxidase and defensin-1.

John Dudman