How would you describe Grapefruit and Cranberries please? We have, at home, always found the taste perception as described for an example in the case of Grapefruit consistently across the brew mediums - espresso, V60 and Clever.
Our knowledgeable members like @MWJB have taken the guess work out of our brew work flows and made brewing easier. When we find the grapefruit flavour as described, we are comfortable to state that there are no brew malfunctions.
It is harder to differentiate the brew malfunction and the flavour from the coffee under these circumstances. The same goes for Rhubarb and hence the reason to try and avoid them. As a fruit, we love all of these three at home. :-)
One way, IMO, to delineate sourness is if it is pleasant or mouth puckering!
