Can you really smell and taste different things in wine? Our resident expert David Carne delves into the ‘mystique’ surrounding wine-tasting
Here’s a question for you. Can you really smell and taste things in wine? If all wine is made from grapes, can people genuinely smell or taste blackcurrant, cedar, violets or pencil shavings? Is it science – or the power of suggestion? Let’s take a closer look and find out…
How we taste and smell
Aromas and flavours come from three interacting systems:
Firstly, Chemesthesis, or mouthfeel. Chemesthesis is the sensations like the burn of chilli, the coolness of mint, the fizz of carbonation, or the viscosity of a liquid. These sensations are triggered by the trigeminal nerve as chemicals react with mucosal surfaces in the mouth, nose, throat and eyes.
Secondly, basic taste. These come from non-volatile compounds detected by tastebuds on the tongue (sweet, sour, salty, bitter, umami). While all these sensations can be detected all over the tongue, the tip and sides are more sensitive generally to sweet and salty tastes, the back to bitter flavours.
Finally, aromas. A significant part of taste is actually smell. As food and drink evaporates in our mouths volatile compounds travel up the nasal passage and activate smell receptors, revealing more complex aromas and flavours. We call this retronasal tasting. But we also detect aromas directly through the nose as well, which is why wine experts like to smell their wine.
So, what might create these sensations in wine?
Different flavours come from different parts of the winemaking process. We refer to these as ‘Primary’ – those that come from the grape, ‘Secondary’ – those that come from the production methods, and ‘Tertiary’ – those that come from age.
Acidity, sugar and bitterness depend on grape variety and ripeness. Riper grapes have more sugar and less acidity; tannins in skins contribute bitterness and astringency, especially in red, rosé and orange wines. Viscosity (or body) is a mix of sugar and/or alcohol, and it can usually be seen in the ‘legs’ or ‘tears’ which run down our glass.
Volatile compounds
Most flavour compounds sit in the pulp just under the grape skin. These volatile compounds – shared with everyday foods – explain why wines smell like non-grape items. Green bell pepper aromas in your Cabernet Sauvignon come from 3-isobutyl-2-methoxypyrazine (IBMP). If you examine green bell peppers you actually find the same volatile compound! Thiols in Sauvignon Blanc give the passionfruit aromas, Rotundone in Shiraz gives black pepper flavours, terpenes create floral smelling wines, Ethyl cinnamate gives Pinot Noir its strawberry nose, and many more. In other words, it is more than just the mere power of suggestion.
Production methods
Secondary aromas come from processing of the grapes. Fermentation produces alcohol, which we often detect as a warm sensation. Lees ageing (letting the wine mix with dead yeast cells) produces biscuity, brioche notes. We also sometimes allow a bacteria to convert the harsh malic acids to softer lactic acids (like those found in milk) – malolactic conversion. This gives creamy, smoother, buttery flavours and mouthfeel. Oak introduces all kinds of flavours depending on the type of barrel, the level of toast it has received and whether it is new or used. Volatile compounds in oak are similar to things like vanilla, cloves, coconut and the toasting can contribute smoke, toast, chocolate, coffee and other aromas.
Ageing the wine
Tertiary aromas are about how the wine changes chemically as part of ageing. With time, oxygen and internal chemical reactions shift fresh fruit towards dried fruit, and introduce complex flavours such as mushroom, forest floor, nutty or leathery notes.
Pulling it all together
The final product is a mix of all these different chemicals interacting together. But don’t worry if your wine just smells like wine! Identifying aromas and flavours takes practice. And bad news for us men… women on average have a better sense of smell, so have an advantage.
Next time you pour a glass, take a moment to swirl, sniff and explore – you might recognise more than you expect. And whatever you choose, please drink responsibly.
DAVID’S RECOMMENDATIONS FOR FEBRUARY
Something Fresh and Fruity
Kleine Zalze Sauvignon Blanc – £10, Waitrose.
A great example of pyrazines – plenty of green bell pepper, tropical fruits, citrus and sharp acidity. Expect an explosion on your palate.
Something Sparkling
Crémant du Jura – £8.19, Aldi.
Crémant is a great source of good quality sparkling wine and this one from Aldi, doesn’t disappoint. Apple and citrus with subtle brioche to finish.
Something English
Gusbourne Blanc de Noir 2019 – £65, The Champagne Company.
With 27 months of lees ageing you’ll be spotting the brioche alongside the citrus, red fruits and fruits of the orchard.
Something Big and Bold
Beronia Rioja Reserva Red Wine – £16.50, Sainsbury’s.
Red fruits and cherry focus, with nice coconut, vanilla and spice on the finish. Not overly oaky, and smooth tannins.
Something Classic
Domaine Bernard Michaut ‘Beauroy’ Chablis Premier Cru 2022/23 – £34, Majestic.
Apple, pear and melon with some honeysuckle and strong mineral notes. Long finish and complex.
Something Different
M&S Classics Cote De Provence Rose – £10, M&S.
Dry and refreshing with strawberry, cranberry and redcurrant notes. A nice floral note with some well-integrated citrus. Delicate and great value at this price point.