“I’m easily distracted by smells,” says Ann Noble, professor emerita of viticulture and oenology at the University of California, Davis. “Nobody has chucked me into an MRI to find out if I process things differently from other people ... I’m a bit like a dog, I haven’t evolved. I listen to my nose. My mother always said, ‘You could smell burned pots before anyone else.’”

The retired sensory chemist is most famous in wine circles for inventing the Wine Aroma Wheel in 1984. The first woman hired as a faculty member of the university’s viticulture department (in 1974) had realized that the wine industry lacked a common vocabulary, or at least one that “you didn’t need a portable linguist to understand.”

“We needed a vocab so that people in the wine industry could communicate with each other – in the wine cellar in the sales room, in the tasting room," explains Noble. "So they could say this wine is ‘blah blah blah,’ and other people would have a clue what they were talking about ... Oh, and by the way, we could also improve it for consumers.”

Drawing on the expertise of contacts in the wine industry and the insights of students in weekly sensory evaluation sessions, Noble started to construct a list of words. She then began to delete what she calls “dorky” words that were commonly used in wine tasting – words such as "luscious, elegant, harmonious or flabby" – which might describe a certain wine quality (to those in the know) but defied objective definition. “All those terms were integrative and judgmental and individual,” Noble says.

The result was the Wine Aroma Wheel, a visual graphic that divided the different wine aromas into 12 basic categories: chemical, pungent, oxidized, microbiological, floral, spicy, fruity, vegetative, nutty, caramelized, woody and earthy. These were then broken down into sub-categories. Fruity, for instance, had the sub-category of dried fruit, which could be broken down into strawberry jam, raisin, prune and figs.

The wheel also included those less-appealing aromas that might indicate a fault, such as the microbiological scent of sauerkraut, and aromas such as "horsey" and "mousy."

“Mousy is a serious problem in sweet wines primarily; it smells almost like stale popcorn,” says Noble.  “The compounds are very similar. Mousy smells like – well, you have to go to where there are mice.”

Readers might have learned at school that taste and aroma are two different things. The tongue can identify only five tastes (salty, sour, sweet, bitter and umami), based on the different molecules or ions that bind to the taste cells on the tongue. Aroma, however, is infinitely variable – the result of the olfactory system processing those volatile thiols that have entered the nasal passages, through both the nose and the mouth.

It is now recognized that while taste and smell are different, they are also inseparable. “Smell and taste are integrated in the brain at the higher levels of processing, so it’s an artificial construct to say that, ‘This is a smell and that is a taste,’” says Noble.

The brain, of course, also influences how we perceive taste and smell. A cheap bottle of plonk sipped on the banks of the River Loire, alongside someone you’ve just fallen madly in love with, might taste terrific, but in less-heady circumstances it might also taste like rubbish. How so?

“It was so great back then, because of the mood, the ambience, all that stuff that totally affects the pleasure part of your brain," explains Noble. "Your cognition is influenced by alien information that has nothing to do with physical smell and taste ... Or, in other words, marketing works.”

But if our experience of a wine drunk in the context of life resists scientific categorization, the aroma wheel offers an objective framework; it can help people to identify exactly what makes one wine distinct from another. It also prompts wine lovers to get in touch with their nose.

“I always tell people that I expect them to outgrow the need to use it,” says Noble. “It’s a way to start. And then people will have the ‘a-ha’ moment; they’re connecting with the smell, the identification of the smell. This helps you start that.”

Twenty-eight years after she first published her Wine Aroma Wheel, Noble still sells it online (as a laminated cardboard disc and on T-shirts). She also gives short courses on wine tasting and serves as a wine judge.

Over the years, she has won numerous accolades. This year, IntoWine.com named her one of the top 100 most influential people in the American industry. Noble says these things are a matter of taste. “It’s integrating all kinds of facets of things that are intangible. My work has hit the fancy of some people, but a number of others could have been chosen.”