Corks could slow ageing in wine

Natural corks may release phenolic compounds which can slow the ageing process and increase the health benefits of wine, according to Paulo Lopes, oenologist and member of Amorim’s R&D team.

Speaking at the Wine Faults Workshop at the London International Wine Fair last week, Lopes said: “Natural corks are rich in phenolic compounds and we are looking at whether they can migrate into the wine.”

According to research conducted at the University of Oporto, cork dust has been found to have both anti-oxidant and anti-cancer properties.

However, Lopes added: “With a whole cork we don’t know if these phenolic compounds are able to migrate and if they contribute in a positive way to the wine.”

Meanwhile Lopes presented research to show that the main source of oxygen in wines sealed with cork was not from the atmosphere but from the cork itself, and that it was released primarily at bottling when the corks are compressed.

This explains, he said, “Why oxygen entry occurs in the first two to three months [for wines closed under cork] and then stabilises.”

He added that testing oxygen transmission rates over a 24 month period on wine bottled under a range of closures showed that synthetic closures gave the highest levels of oxidation and screwcap the greatest levels of reduction, while cork sat somewhere in the middle.

Ronan Sayburn MS, director of wines at Hotel du Vin, was also present and talked through a series of wines with different faults.

Addressing the delegates at the event, he said: “The most common wine fault is oxidisation and you often get it due to heat damage, especially if there is a lot of temperature variation because if there is thermal expansion and contraction of the cork then it works like a piston drawing oxygen into the liquid.”

Patrick Schmitt, 26.05.2011