This years honey harvest was my largest to date; twice as much as last year. This was surprising given that 5 production colonies suffered from CBPV and the associated mortality.
I was curious to see how much honey and wax was in each frame and how the yield could be affected by this.
For a honey bee colony the cost of making wax is immense; they have to ensure there is a flow of nectar, bees of the right age must be diverted to produce the wax, but only once the temperature is high enough to make it malleable.
For the beekeeper the cost of producing wax is also large; mainly because all of the potential nectar which could be turned into honey is going into wax. They are also likely to stimulate wax production by providing a light sugar syrup. The sugar syrup must be topped up and the beekeeper must ensure that it doesn’t adulterate the honey crop.
To explore this balance between wax and honey production within my colonies, I turned to the frame weight data that I have been gathering all season.
As I took each frame out of a box I scraped off any large amounts of wax on the top bar and sides. I then put the frame, resting on the top bar, on a set of digital scales. After uncapping the frames were put in a tangential extractor for 2-3 minutes per side. Empty frames were then weighed again.
- Total Number of Frames Weighed: 91
- Frames weighed:
- 6x 14x12
- 44x DN4
- 29x DN5
- 12x SN4
- All frames are Hoffman spaced and this was retained even in supers
- 15 frames had a single solid bottom bar
- 76 frames had the standard 2 bottom bars
- Most frames only included a starter strip between 2cm and 10cm so the comb was naturally built
- 1.76kg is the average weight of a frame before uncapping
- 1.30kg is the average weight of the honey extracted per frame
- 90% is the average wax percentage of a frame (i.e. there are gaps,
normally a beespace above the bottom bar)
- I did not measure precisely, this is an approximation
- 268g is the average weight of the wax in the frame
- This has been adjusted to accommodate the reduced area of the frame and remaining honey in the frame
It takes 268g of wax of to fill a frame 90% full.
Previous studies suggest that the cost (in honey) for wax production can vary between 5.99kg and 6.6kg. So let’s take the mean value of 6.29kg of honey required to make 1kg of wax.
Honey Required = 6.29 * 0.268 = 1.68kg
So, per frame, 1.68kg of honey is used for the amount of wax produced. For perspective, this is on average 380g more than the total honey removed from the frame.
It should also be noted that this is a conservative estimate which doesn’t account for honey which remains in the empty comb or lost to cappings. This is a difficult to measure due to the labour required to extract it; however, based on observations in these frames, the volume of capped wax could be up to 15% in addition, taking our average weight per frame up to 308g.
Honey Required = 6.29 * 0.308 = 1.94kg
Based on a year’s worth of weight data from a sample of hives, and 91 frames, this short study has given some indication of the volume of wax produced, and applied previous findings to highlight the cost in honey production of this activity. These findings highlight that, to increase honey production, having fully drawn out frames of wax is critical to good yields. This may have several implications for my own beekeeping, and for other beekeepers:
> A bigger honey yield
About 20% of these frames were about to enter their 4th year, so as the NBU advise I have removed that comb from service and it has been rendered down. The frames are awaiting their turn in the oven. So now I’m left with 72 frames of drawn out comb. Based upon the above numbers if next years season mirrored this years then I would expect to further increase yield just from having drawn out frames.
> Older combs were included
This years crop included frames that were newly drawn out and some from previous years. In some cases there was solidified honey which was left in some of the frames. This will have skewed the results slightly
> Foundation strips are key
The image at the top shows 6 SN4 frames filled with honey. Unfortunately they were not fitted with any foundation, be it strips or full sheets. This means that all of the wax had to be rendered down. It’ll be used for foundation or candles.
> More equipment needed
As the bees will not be spending the nectar and honey drawing out wax comb, they will be using the existing comb, the frames will fill up much quicker during a flow. Whereas previously the incoming nectar would be processed into wax to fill up the foundation it can now be stored directly in the cells.
I am going to have to be on my guard and ensure that I have plenty of spare equipment. I will also follow Ian Steppler’s example by putting empty frames at either end of the box to act as a management buffer, it also helps to ensure that there is always fresh comb.
> Storage is key
Wax moths are the saviour of naturally nested colonies but for the honey farmer they are the enemy. You don’t want wax moth larvae eating your comb during the winter! So it’s best to freeze the frames to kill any eggs or any which have hatched.
With thanks to
- Oli Preston for checking my sums and phraseology
- Sara Churchfield for applying her beekeeping knowledge to my findings
- Beeswax Production, Harvesting, Processing and Products, Coggshall and Morse. Wicwas Press. 1984-06-01. ISBN 978-1878075062.
- NBU: Replacing Old Brood Comb. http://www.nationalbeeunit.com/downloadDocument.cfm?id=1074
- Ian Steppler: Next stage of managing spring hive development- beginning of May. https://youtu.be/Fil1Zqvn6bI?t=126