[chiralSPO (OP)]

You couldn't use the stuff we normally call "sugar" to make fake honey; it's sucrose and honey is largely glucose and fructose.

Depends how it’s done. When there is a poor nectar flow - we are about to enter one - beekeepers feed sucrose solution to tide the bees over. The bees will invert the sucrose, but you end up with a diluted flavour so you can’t (or rather shouldn’t) extract it for sale.
We also use an invert syrup with same glucose/fructose mix as honey so the bees don’t waste energy converting it, but same problem of saleability. Unscrupulous people could add the invert directly and I think this has been detected in imported honey.

But you could use golden syrup- which is a partially inverted sugar (and thus is much more similar to honey).

Honey police will get you 
Golden syrup contains high amount of 5-hydroxy methyl furfural (HMF). Honey is tested for HMF as it is a sign that the honey has been overheated in processing and adding golden syrup would push it above the legal limit.
Most amateur beekeepers don’t heat their honey in order to keep it as natural as possible.

Testing for fakes is interesting enough as a piece of analytical chemistry, but more than a little off topic.

That would be a very interesting topic. Particularly if you know a simple test to identify sucrose in honey.

Does polarimetry count as simple? I would expect that even a rudimentary polarimeter should be able to identify if significant amounts of sucrose had been added to a fructose/glucose mix…

https://en.wikipedia.org/wiki/Specific_rotation

[Bored chemist]

Apparently, they do.
https://www.anton-paar.com/corp-en/products/applications/determination-of-honey-purity-and-quality-by-polarimetry/

[Colin2B]

Does polarimetry count as simple? I would expect that even a rudimentary polarimeter should be able to identify if significant amounts of sucrose had been added to a fructose/glucose mix…

https://en.wikipedia.org/wiki/Specific_rotation
It’s certainly simpler than mass spectrometry which is often quoted

Apparently, they do.
https://www.anton-paar.com/corp-en/products/applications/determination-of-honey-purity-and-quality-by-polarimetry/

That still sounds expensive, but I’ll investigate. Thanks

[chiralSPO (OP)]

There is always an expensive way, and a less expensive way. If you need high throughput and high precision it's gonna be expensive. If you want to check that the monthly jar of honey purchased from the farmers market isn't 20% sucrose, I bet you could do it with a $100–200 budget:

you'll want a sodium lamp, two polarized filters and a photodetector/meter along with a cuvette.

see also:
https://pubs.acs.org/doi/10.1021/acs.jchemed.7b00767
https://www.bonanza.com/listings/NEW-Disc-Polarimeter-with-Sodium-Lamp-180-degree-Brix-Refractive-Index/159040957?goog_pla=1

[Bored chemist]

There is always an expensive way, and a less expensive way. If you need high throughput and high precision it's gonna be expensive. If you want to check that the monthly jar of honey purchased from the farmers market isn't 20% sucrose, I bet you could do it with a $100–200 budget:

you'll want a sodium lamp, two polarized filters and a photodetector/meter along with a cuvette.

see also:
https://pubs.acs.org/doi/10.1021/acs.jchemed.7b00767
https://www.bonanza.com/listings/NEW-Disc-Polarimeter-with-Sodium-Lamp-180-degree-Brix-Refractive-Index/159040957?goog_pla=1

maybe...
But it seems that some honey is 10% or so disaccharide (which may well be sucrose).
Also the proportions of glucose and fructose differ a bit.
https://www.researchgate.net/publication/257742572_Physicochemical_and_melissopalynological_characterization_of_Estonian_summer_honeys

If I was making a polarimeter, I'd not bother with a sodium lamp; I would just use a yellow LED.
And I'd not bother with any complicated photometer. I'd use my eyes.

But measuring the polarisation of honey won't tell you much.