Honey is expensive and manuka honey fetches especially high prices - so it's important to prove it's the real thing.
That's something GNS Science senior scientist Karyne Rogers has been working on, and she talked about it at the National Apiculture Industry conference in Wanganui on Monday.
She was one of several experts helping beekeepers test honeys for taste, colour, moisture content, pollen grains and mineral content. People moved from table to table, listening and trying out the various tests in a hands-on honey workshop.
Dr Rogers said New Zealand beekeepers didn't adulterate manuka honey with other honey or sugar, but that was sometimes done in Asia and Europe. Sometimes that honey was then labelled as being from New Zealand.
The result was that countries such as the United States had import alerts on New Zealand honey, and a third of all honey was affected.
A major problem is the Association of Analytical Chemists' test for a sugar that's used to adulterate honey. The test has been giving false positives for New Zealand honey, dropping its price and damaging its reputation.
Dr Rogers is working with the Government to define what manuka honey is and give guidelines to the countries that test it. "There's no one test that will tell whether it really is manuka honey," she said.
Some of the importing countries were listening but they had been slow to change their laws.
She said there were encouraging signs that manuka honey had healing properties but there was not enough scientific evidence to convince the medical establishment.
Other yet-to-be discovered New Zealand native plants might have equally valuable nectars for honey. Rewarewa and kamahi were both possibilities.
"We know very little about the values of native honeys apart from manuka and kanuka.