I'm not sure whether things are actually imaginary, or whether they might just have a lower perception threshold. In beer tasting, we talk about off-flavors li

I'm not sure whether things are actually imaginary, or whether they might just have a lower perception threshold. In beer tasting, we talk about off-flavors like green apple, butterscotch, cooked cabbage, or flavors like spicy/peppery, cloves, bananas, citrus, passionfruit, etc. None of these are imaginary, as each of these are linked to a specific chemical compound, such as acetaldehyde, diacetyl, DMS, various phenols and esters, and of course hop oils and various humulones, cohumulones, etc. from the hops. What would help in wine tasting would be to link each aroma and flavor to specific chemical compounds, it would make detection more objective and make it possible to tell apart the very real aromas and flavors from the imaginary ones.