Thanks Seppo Korpela for your additive information! I'll try to find the article. /Unit for HMF is normally mg/kg instead of % Sorry, 'percentage' was an translation error. Right now I have 3 questions: - Refering to the text of Seppo Korpela: /According to G.L. this study contains information on /HMF changes in honey when liquified by microwaves, but he does not tell /these results in the article. Does anyone have any test-results of heating honey with a microwave, or knows where I can find them? - How can I preserve/conserve honey so that the HMF will increase in the most slowly way by the rising of the years? - I'm a member of a beekeepers-club where we discussed the results of a honey-contest. The winners always heat there honey to liquify it and the honey gets a golden-yellow color. For the "pure" beekeeper, it is sometimes a crime to get in a natural way the same results. The only (?) way to check if the honey has been heaten is to decide the HMF (in a laboratory). Is there an easy way to check if the honey was heaten? May be a cheap instrument (that every beekeeper could afford)? I would be grateful for any help. Peter van Empel