Sugar for the Beekeeper
Last month we learned where our imported sugar came from – namely Australia, Malaysia and Thailand – and before that we looked at how bees use it. Now, in part three of our series on sugar, resident science writer Dave Black explores how beekeepers use sugar in New Zealand, from raw, to liquid, invert and even candy.
By Dave Black
Most of the sugar refining is done overseas. Process-grade raw sugar we import is dissolved and re-crystallised here in a controlled manner to supply the various consumer ‘grades’, distinctions made mostly according to crystal size and colour.
White and raw sugars
The grade we are most familiar with, white, granulated sugar, is 99.85% sucrose, contains very little moisture (<0.04%) a small amount of insoluble material (5mg/kg or 0.0005%, 0.02% ‘ash’), and virtually no yeasts, fungi or bacteria. Provided it is kept dry it will store perfectly well for several years.
The consumer product labelled ‘Raw’ sugar (not actually raw cane sugar) differs in a few ways. The moisture content is a little higher (0.3% max), there is significantly more insoluble material (60mg/kg or 0.006%, still a tiny amount), more sodium, and the amount of yeasts or fungi can be higher. The higher microbial counts and moisture make this a little more sensitive to storage conditions in that fermentation becomes a possibility, but properly stored it too can be kept for years. The ‘ash’ and insoluble portion is largely indigestible residues bees would prefer to avoid, but for consumers it is responsible for some of the colour and character they value, sometimes symbolic of more ‘natural’ sugar.
Both white and raw sugars – intended as fit for human consumption – do not contain anything in sufficient quantity to be relevant to bee health, other than sucrose. Either can be used dry, and in New Zealand dry raw sugar is often used. In the northern hemisphere, where it’s colder, dry feeding is usually reserved for emergency rations. Depending on the scale a beekeeper operates at, dry sugar is usually dissolved in water to supply a DIY syrup, a clear sucrose solution. It is also possible to buy some ready-made (Farmlands for instance) in which case it is frequently prepared from raw sugar because that’s cheaper, and this imparts a pale golden tint. In my experience the later doesn’t store as well, but you shouldn’t be storing it!
Liquid sugar is also supplied as ‘Invert’ syrup which is quite a different product. Invert syrup contains very little sucrose (<1.5%) and contains instead glucose and fructose at 65.7% or 70.6%. Apart from convenience, invert sugars are less prone to robbing (sucrose is the sugar most attractive to bees), contain more ‘digestible’ sugars, and are less likely to crystalise or freeze. There are various ways of producing invert syrups but the ‘right’ way to do it, from a beekeeper’s perspective, is by adding an enzyme to the sucrose solution. That way, the resulting feed is not acidic, and HMF production is negligible. For example, New Zealand Sugar’s FLS Invert syrup is supplied with a pH of 8-9, and HMF at less than 10ppm (typically between 1ppm & 5ppm). For context, freshly extracted honey would have HMF at about 10ppm and the honey you sell is not allowed to contain more than 40ppm.
Candy and fondant
It’s worth just mentioning two other forms of sugar beekeepers come across, ‘candy’ and ‘fondant’, You will hear of ‘candy boards’, or might have used ‘candy’ in queen cages. You may see these used interchangeably to describe quite dissimilar homemade and commercial products. A fondant (as in cake icing) is a thickened sugar syrup, thickened with a vegetable fat, gelatine, or starch. Another method of thickening is by cooking the syrup to 115°C evaporating a lot the water, and then ‘working’ it to incorporate air and control the crystallisation to a ‘soft’, fluid, ‘set’ (as you do with creamed honey). Sometimes a bit of each process is used!
The second process is also known as ‘candying’, for producing a soft toffee candy. Reducing sugars (glucose and fructose) can be used as an ingredient, or produced by the heating, so both of these are semi-solid forms of invert sugar. Just remember the issue beekeepers have with heating sugar. Practical Beekeeping in New Zealand by Matheson and Reid contains a recipe for creating candy for queen cages which is easy to follow, but a packet of marshmallows is also an effective ‘life-hack’!
Starch syrups and … adulteration
As far as I am aware, so-called ‘starch syrups’ are not used in New Zealand, these include Apifortune, Apikel20 and Apifood. The most well-known type are High Fructose Corn Syrups (HFCS). Sucrose, glucose and fructose can all be produced from starches and besides corn; wheat, rice, and other grains can be used. It’s a more complex process and for bees these all seem to have mixed results, with problems likely due to the creation of acidic pH and high HMF. Created to suit food manufacturing, they don’t seem to me to be particularly well suited to honey bees, even if some of them are effective honey ‘mimics’, or, as we know them, adulterants.
That’s another story though. For now, I hope you have learnt a bit about the types of sugar you might be feeding your bees and where it has come from.
Note: New Zealand Sugar, a major supplier to apiculture, was consulted for information in this story.
Dave Black is a Bay of Plenty based hobbyist beekeeper who now works in the kiwifruit industry. He has a degree in Environmental Science and for the past 25 years he has been reading and writing about bees and beekeeping. His essays are available at www.beyondbeebooks.substack.com/
References:  (<10 cfu/10g on Yeast and Moulds and <1000 cfu/10g of bacteria).  New Zealand Sugar.