Why do some wines have a slight fizz?

You know that subtle fizz you sometimes notice in a glass of white or rosé? It's carbon dioxide — the same gas that makes sparkling wine bubbly, just in much smaller amounts.

During fermentation, yeast converts sugar into alcohol and CO₂. For most still wines, the gas escapes during winemaking. But if a winemaker bottles the wine early, some CO₂ stays dissolved. Open the bottle, and you'll feel a gentle prickle on your tongue. This is completely deliberate in wines like Portuguese Vinho Verde, Basque Txakoli, and many young Muscadet.

There's also a growing category called Pétillant Naturel (Pet'Nat for short), which uses the oldest sparkling winemaking method around. The wine goes into the bottle while it's still fermenting. No added yeast, no added sugar — just the original fermentation finishing in the bottle. The result is a gentle, often slightly cloudy fizz that's become hugely trendy.

Sometimes, though, the fizz is unintentional. If a wine has a tiny bit of residual sugar and some active yeast cells survive bottling, refermentation can kick off inside the bottle. In white wines, this can be harmless or even pleasant. In red wines, it usually feels out of place and is considered a fault.

If you open a still wine and notice unexpected bubbles, give it a swirl in your glass. If the fizz dissipates quickly and the wine tastes fresh, it's likely just protective CO₂ from early bottling — nothing to worry about. If the wine smells off or tastes yeasty, the refermentation may have gone too far.

Pro tip: wines with a slight perlance are brilliant with seafood, sushi, and light salads. That bit of fizz lifts the flavours and cleanses the palate between bites.