A new paper from researchers in Naples, Italy, asks a practical question: as climate change makes some red wines higher in alcohol and alters their acidity, does that also change how strongly certain aromas are released and perceived?
The researchers focused on two naturally occurring aroma compounds, γ-nonalactone and massoia lactone. At noticeable levels, these can contribute sweet, cooked-fruit aromas such as prune and dried fig. In some dry red wines, these notes may be interpreted as over-ripeness or premature ageing rather than desirable fruit development.
They took one red wine, removed most of its original aroma, and rebuilt it in nine versions. These ranged from 12% to 16% alcohol and had different combinations of pH and total acidity. The researchers then added fixed amounts of the two aroma compounds, measured how much escaped into the air above the glass, and asked 24 trained tasters to assess the wines.
Alcohol and acidity did not act independently. Together, they changed both how readily the aroma compounds escaped from the wine and how the brain interpreted the overall smell and taste.
The two compounds were especially detectable in the 16% alcohol wine with the strongest acidic profile. This suggests that acidifying a very alcoholic wine may sometimes make certain prune-like or prematurely aged aromas more noticeable, even though acidification is normally used to restore freshness and stability. Simply “adding more acid” may therefore not solve every heat-related imbalance.
A wine’s aroma is not determined solely by which flavour compounds it contains. Alcohol, acidity and the rest of the wine can make the same compound seem stronger, weaker or qualitatively different.
A high alcohol figure on the label does not automatically mean a bad or “climate-damaged” wine. However, in a very ripe red, the combination of high alcohol, weak freshness, heavy body, bitterness and pronounced prune or dried-fig aromas may reflect the sort of imbalance examined here.
