How much heather to make extraction difficult.

[Sutty]

I'm not familiar with the apparently distinctive smell or taste of heather honey. I'm just extracting again after some supers refilled rather fast. It doesn't look smell or taste much different to the last lot (maybe a bit darker) but has been very reluctant to spin out until I ran a spiky "heather roller" over the combs before spinning.
I'm guessing there's just enough heather in it to give a problem!