Telling real honey from the rest

AHoney is among the most adulterated foods in world trade, and the reason is arithmetic rather than wickedness. It sells for several times the price of the syrups that can be made to resemble it, it is a liquid that can be blended in any proportion, and the blending leaves no visible trace. Where those three things are true of any product, adulteration follows.

BThe crudest method is simply to add sugar syrup to real honey, and for most of the twentieth century this was easy to catch. Honey is made by bees from the nectar of flowering plants, which use one photosynthetic pathway, while cane and maize use another, and the two pathways leave different proportions of carbon isotopes in the finished sugar. A laboratory comparing those proportions could spot added cane or maize sugar at a few per cent.

CThe response was to switch to syrups made from rice and beet, which use the same photosynthetic pathway as most nectar plants and therefore produce the same isotope signature. This is the pattern the whole field follows: a test is published, the people it is designed to catch read the publication, and within a few years the cheapest way to defeat it is known. Detection and adulteration are not two separate activities but one conversation.

DThe current generation of tests therefore looks at what honey contains besides sugar. Real honey holds traces of pollen, enzymes added by the bees themselves, and a large number of minor compounds that vary by region and by season. A syrup contains none of these, so the question becomes whether the mixture has the right company of trace substances rather than whether the sugar is of the right type.

EThis has produced an awkward complication, because much of the honey sold is filtered to remove pollen, and the reasons for filtering are legitimate. Pollen makes honey cloudy and makes it crystallise faster, and consumers reject both. A producer who filters is therefore removing the evidence that would prove their honey genuine, and a test that treats missing pollen as a sign of fraud will condemn a great deal of honest product.

FOrigin is a separate question from authenticity and is harder. A jar may contain real honey and still be mislabelled, because the price depends heavily on where it came from. Pollen analysis can indicate a region, but blending several origins destroys the signal, and most supermarket honey is blended by design. The honest position is that current methods can often establish that honey is honey and can rarely establish where it grew.

GWhat has changed the economics more than any laboratory method is traceability at the point of collection. A system that records which hives produced which barrels, verified by somebody who visits, makes adulteration a matter of catching a person rather than detecting a molecule. It is unglamorous, it does not produce a publishable method, and in the places that have adopted it seriously the price difference between verified and unverified honey has become large enough to pay for the verification.