The Corkscrew | In praise of pét-nat: hip new wine craze adds affordable sparkle

The newest “pet” in the wine world is pétillant naturel, known in geek speak as “pét-nat”. It’s a cute term for a natural wine with a bit of fizz that can be quite foamy when opened, and ranges from bone dry to a little on the sweet side. But, although it is trendy, pét-nat is not new.

One could call it retro because the tech­niques involved in this style of wine are very old: méthode ancestrale is said to be the earliest traditional way of making sparkling wine. Most likely, this was hit upon accident­ally, when it was noticed that fermentation had been slowed or stopped by unexpectedly cold weather. A French winemaker would have bottled his wine, assuming that it was ready. When opened, it would have been discovered that ferment­ation had restarted in the bottle and that it now contained bubbles. Méthode ancestrale precedes the méthode traditionnelle technique used to make champagne.

What makes pét-nat wines distinct is that no sugar is added; fermentation depends on natural yeasts on skins of the grapes, and bubbles are a by-product of fermentation. The tricky part is in bottling the wine at just the right time: what I call the “wine interrupted” moment, when most or all of the natural sugars in the grapes have been consumed by the natural yeasts, but fermentation is still vibrant.

It sounds easy, but there are a few things to watch out for. One is the sediment (the lees) left over from fermenting grapes – fermenting lees could increase the pressure in a bottle to exploding point. With méthode traditionnelle, disgorgement removes this problem. This starts with riddling, whereby a bottle is gradually spun from upright to an upside-down position, so that sediment migrates to the bottle’s neck. The bottle is then chilled to almost freezing and opened so that a small amount of wine, including the part with the sediment, is allowed out. If no disgorgement takes place, which is often the case for pét-nat wines, a light filtering (at the very least) should be carried out before bottling.

Pét-nat wines are bottled without the addi­tion of any sulphur dioxide as a preservative. It is essential to have absolute cleanliness in the winery to avoid oxidation and other spoilage issues. These wines are meant to be enjoyed young.