HydroxyMethylFurfuraldehyde

HydroxyMethylFurfuraldehyde, apart from being a spectacular headline, is also known as HMF and strikes terror into the hearts of some honey sellers. HMF isn't harmful, but it is an indicator of the heat honey has been exposed to or how long it has been stored. The European Union uses it as a quality indicator with limits above which the honey must be classed as "bakers' honey".

There's an interesting debate on Bee-L at the moment if HMF is actually a trade-protection tool used by the EU. If you are in a hot country, it can be pretty damn difficult to keep HMF levels down even if you don't heat your honey.