If he ever had fresh Knapweed honey he would change his mind. you put it in your mouth and you have that sweet delicious taste and as the honey is dissolved and washed away, once the honey is gone what you are left with is the most bitter taste that will not go away. the sweet honey taste last 30 seconds, It takes 3 minutes to loose the knapweed taste from your mouth. To describe the taste ever have a little car battery acid residue on your fingers and end up tasting a little of it. or residue from acid flux soldering paste. that is the after taste it leaves.
The taste comes from oils in the plant that are picked up in the nectar. This is the reason the bitter taste lingers after the sugars have dissolved. If left in an open container for 6 months and allowed to vent most of the oils will evaporate and the after taste will be much less, but is is still there and I can taste it.