Geosmin – an organic compound from a type of bacteria which deliver a rich earthy scent akin to soil, mushrooms or beetroot.
Volatile Acidity – another type of bacteria commonly present during the process of winemaking. A complex, almost pickled or vinegar flavour when in small amounts, but unappealing and very acidic when there is too much.
Sulphur – UV damage can cause a sulphurous scent to take on a woolly note, which is very undesirable in wines. But certain sulphur compounds provide wonderful minerality.
Brettanomyces – A type of phenol (a compound found naturally occurring in peppers, among other plant sources) which comes about as a result of adding a wild yeast to the mix. Expect a pleasant, yet almost medicinal tone from this similar to clove.
Lactones – By its name, you might imagine ‘spicy’ aromas to stop at peppery notes but lactones fall into this category and surface as creamy aromas. Honey, vanilla and coconut are all examples of this delightful flavour.
Rotundone – A classic pepper often found in reds. This particular terpene is also found in essential oils of oregano and black pepper, so you can imagine the kick!
High Dose Thiols – In stark contrast to the thiols found in fruity notes, high doses of this in a wine will present to the palette and nose as distinctly smoky and bitter.
Botrytis – Although this is a fungus which loves ripe fruits, the inclusion of this in wine is not considered a bad thing! This can add a rich honey or in lower concentration, a chamomile note.
Low Dose Thiols – Not all fruit notes in wine are sweet, some are on the bitter end of gooseberry and grapefruit and these are the result of organosulphur compound, thiol.
Pyrazines – Grassy, green aromas like that of elderflower or even grass itself come from this organic aromatic compound.
Esters – Despite coming from acids, esters give that very sweet fruity flavour often described as juicy berries in red or apple in a sweet white.
Terpenes – The most classically floral of the bunch, but with a unique versatility which can come across as resinous.