That's what I was wondering if a yeast culture has been used for decades, like farmhouse strains of Kveik whether, they mutate and take on a funkiness of their own.I find that many of the older English breweries that have their own yeast often have a very slight phenolic character to them; I can detect it in Bateman's yeast, as well as a couple of others. Not Belgian levels of funkiness, you understand, but a slight hint that is very pleasant.
Bit then, my taste buds are wierd, so that might be complete balderdash.
I didn't get that green apple phenolic twang, more a funky greasiness coating your mouth and as I had the same texture with the different tastes of each beer I am guessing it's the yeast, 4 different ales, same aftertaste.