I met a friend for a beer this week and had a server describe a stout on the menu as sour. Upon having a sip, there was an overwhelming deep – and for a stout – satisfying bitterness with just a hint of sweet but surely no sourness. I bring this up not to complain about the service or beer (because both were great) but to point out how often we confuse terminology when discussing taste.

A core part of such befuddlement originates in the conflation of ‘taste’ with ‘flavour’. Most commonly in English, taste refers to the five elements our tongue can identify: sweet, sour, bitter, salty, and umami. To draw upon Bob Holmes, it extends from the question, “do I want to eat this?” He writes, “taste is all about the broad categories of good and bad” and alludes to the evolutionary prerogative to avoid eating harmful foods or toxins.

Flavour, on the other hand, encompasses the act or experience of tasting something. It answers “what is it?” Thanks to our olfactory and gustatory systems, we can make sense of the massive array of odorant and flavour molecules in something like a cup of coffee. Through numerous highly complex sets of nerve cells, our brains cut through the complexity and allow us to see a harmonized and unified ‘flavour perception’.

So back to the stout, why would it be considered sour? Well, it was barrel aged in wine casks, so it contained some base notes broadly associated with red wine. The berry of a cab franc or cherry of a merlot or the plum of pinot noir, for instance. So if you compared it side-by-side to a non-barrel aged stout, it would be more sour for sure. However, I think the key flavours (again, the amalgamation of that complicated sensory information) were more the sweetness of a milk biscuit along with the bitterness of burnt or charred greens.

There is a simple but important message in all of this: taste and flavour are complicated! Over the next couple weeks, I want to build on this starting point to discuss the effects of flavour in coffee and mull over how perceived expertise in tasting operates within our industry. Fun, I know, right?!?