Although it says nothing about coffee I though it might explain why often our cupping notes vary.
From Todays Age.

BO is all in the genes

September 18, 2007 - 10:31AM

Body odour can smell sweet to some, and foul to others, and it all comes down to genes.

A US study has found a potent ingredient in male body odour can smell like stale urine or vanilla, depending on variations to a single odour receptor gene.

Scientists from two universities made the discovery after exposing 391 people to 66 odours, and asking them to rate each one for pleasantness and intensity.

The smell tests included androstenone, which is derived from testosterone and found in higher concentrations in urine and sweat in men than women.

The researchers found adrostenone activates an odour receptor known as OR7D4. They used DNA testing to reveal that participants responses differed based on which variation of this gene they had.

One group that had the same variation said the odour was foul and intense. Another group were less likely to think the odour unpleasant - with some describing a hint of vanilla - or were unable to smell it at all.

Some mammals use androstenone to send out social and sexual signals, and the researchers say their findings raised "intriguing" questions about whether it had a similar effect in humans.