A stream of tiny bubbles rising continuously up through a glass of sparkling wine has long been thought of as an indicator of quality. Winemakers believed if the wine underwent its second fermentation in a cool cellar, the resulting bubbles would be small and delicate. But research by Professor Gérard Liger-Belair, at the University of Reims, found that more aroma was released as larger bubbles reached the surface of the wine whereas in wines with very small bubbles, aromas were subdued.
Bubbles are dependent on other factors too. Dissolved CO2 is only released to form bubbles when molecules find spots known as nucleation sites. These can be scratches on the glass or fibres left behind when the glass was polished. This means that the glass you choose and how it was cleaned can have an impact on how the wine displays its bubbles. And why two glasses of an identical wine may display different amounts of bubbles.
Not really. The current vogue for minimal intervention wines means that some are now labelled as ‘sulphur free’ as though a sulphur dioxide addition is winemaking evil. But sulphur has been used by winemakers for centuries and indeed is itself a natural by-product of fermentation, produced by the action of the yeast. So even if the label claims that the wine has had no sulphur additions (some winemakers are choosing not to add additional sulphur either during the winemaking process or at bottling) no wine can claim to be completely free of sulphur dioxide.
It is worth noting that sulphur additions are strictly regulated so even ‘conventional’ wines usually only have the minimum the winemaker thinks will keep the wine in condition.
Corks can be an excellent method of sealing bottles providing the bottle is well stored and the cork doesn’t dry out. Unfortunately a warm cellar or a bottle stored upright rather than on its side can allow the cork to dry out and lose elasticity which allows oxygen to enter the bottle. This usually results in an oxidised, and therefore lesser quality wine.
I’d use an Ah-So rather than a traditional corkscrew if you suspect your cork may be difficult to remove as this method gently removes the cork and causes as little damage as possible. Once opened you can then taste for faults such as cork taint. It is worth noting that sometimes even young wines have a brittle cork so even though the wine is still in good condition, the cork is difficult to remove.
Got a wine-related question?
Those whose letters are published will receive a bottle of wine (18+ years old only).
Photography courtesy of Champagne Bureau Australia