This article is circulating among beekeepers right now. Everyone needs to know how bad it is that fake honey is in the market. I tell everyone to buy local honey - better yet, buy from a beekeeper you know. This article focuses on on-purpose dilution of true honey.
As beekeepers, we also are possibly bottling honey that isn't real unless we truly take precautions. If you never feed your bees, then most likely your honey is pure nectar-based honey (unless your bees find a candy factory as in this article!). The French bees in the article produced blue and green "honey."
To be absolutely sure that you are harvesting pure honey, there are a couple of things you can do:
1. When/if you feed your bees, put food coloring in the sugar syrup. Blue is a good choice. Then if you pull a frame to harvest and the honey is blue or bluish, you can know that the honey contains sugar syrup.
2. Put a mark on the boxes that were filled with honey before you feed the bees and you can be assured that if you harvest from the marked boxes, you'll have pure honey in the frames and not honey that has been contaminated with syrup.
3. Never feed your bees during the nectar flow.
This is not an issue for me in that most years I don't need to feed my bees and if I feed the bees, I harvest long before that happens.