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…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.