Can a beer taste different depending on our mood?

I just think the connection between your taste buds and part of your brain that governs mood is one-way. Inconsistencies can result from a single bacteria or errant yeast strain managing to get into an otherwise clean bottle before it's filled (nobody's perfect), from a tiny crack in the bottle due to mishandling, from more light or heat hitting one bottle than another, even within the same six pack. It does happen.

 

If it applies to McNuggets, it applies to beer. As has been said over and over already. Taste is subjective and can be easily influenced by outside stimuli, like advertising and/or expectations

 

As it turns out there are some indications its bi-directional. Here is a link to a news article which mentions but does not provide a link to the research study:

http://articles.latimes.com/2012/sep/06/health/la-he-food-morals-20120818

Note: those tiny imperfections you mention do sometimes happen but its pretty rare. So rare I've never had it happen to me.

 

Sensory processing, especially the sense of smell which is such such a large piece of how things taste, is still in large measure a "black box." We sort of know how the sense organs work, although again least of all the sense of smell, but the sense organs are just sensors/receptors, the information processing appears to all happen in the brain. For taste, as far as current science understands, we're strictly limited to degrees of sour, salty, bitter, sweet and umami, everything else in taste comes from scent. Old theories of scents coming from molecular receptors seem to be well on the their way out, being replaced by theories that involve atomic or even subatomic/quantum interactions. Further, we know that scent can be a powerful memory, and hence association/mood, trigger. I don't think it is a mystery that the same beer can taste different on different occasions and in different contexts. It may be a bigger mystery that they can taste identifiably the same in different contexts and even there truly blind tastings suggest that our ability to reliably identify a beer blind is quite fallible.

 

Yes sure can!