What is Pet Nat (and why should you care)?
In short, a Pétillant Naturel is loosely defined as a sparkling wine made with organic or biodynamic grapes, fermented with indigenous, wild yeasts, and vinified with minimal or no additives and stabilizers. Pétillant Naturel, or Pet Nat for short, falls within the broader category of Natural Wine, which is a complex one to break down. Outside of one small subregion in France, there is no contiguous, legally-mandated set of guidelines around its definition nor its production. This means that we have a wild range of wines that call themselves Natural with an often confusing range of quality and flavor profiles. An absence of oversight like this means that winemakers have a lot of room to play and be creative; it also means that consumers sometimes have a tough time deciphering what they’re drinking. In order to understand this particularly unique category of wine we need to consider both the science and philosophy that drive it.
In the world of wine, there are 6 internationally-recognized methods for producing sparkling wine. Pet Nat is made in the Méthode Ancestrale, which is the original French name for, you guessed it, ‘Ancestral Method’. For our purposes here, let’s compare it to the two most widely-known methods that are used to make Champagne and Prosecco. Méthode Traditionnelle (aka Traditional Method, Méthode Classique, or Metodo Classico) is used to make Champagne, Franciacorta, and others, while the Charmat Method (aka Tank Method or Cuve Close) is used to make Prosecco, Cava, and others. The Traditional Method was historically referred to as the Champagne Method or Méthode Champenoise. This term has since been banned by the EU so now we’ll stick with the names outlined above.
Though related, these processes are unique approaches to a delicious, bubbly end product. The different methods are the result of geographic mandate, economic necessity, and / or creative output. The widely-accepted but not legally defined Méthode Ancestrale is similar to the other methods in that CO2 is trapped during fermentation, resulting in a sparkling wine. However, with Pet Nat, this is typically the result of one extended fermentation as opposed to two distinct fermentations. With the Traditional Method and Tank Method, wine undergoes primary fermentation, in which sugar and yeast are converted into alcohol, heat, and CO2. In this step, the CO2 is released by an opening in the tank or barrel. This is followed by secondary fermentation, in which sugar and sometimes more yeast are added to the wine in order to create additional alcohol and CO2. This time the CO2 is trapped and retained within the bottle or tank to develop a bubbly characteristic in the wine. When all the sugar has been consumed by the yeast, fermentation ends. Once the yeast is done performing its duties, these dead cells become ‘lees’.
Some specific differences that set Pet Nat and its Methode Ancestrale apart from the other winemaking methods are:
- Very little or no sulfites are added (a common benchmark is less than 40ppm / 750mL bottle equivalent)
- The wines are fermented with 100% native, wild yeasts (they’re all around us! In the air, on plants, and on your skin!) rather than packaged, premade yeasts from a lab in France
- Post-fermentation, the lees are not racked (removed via filtration) or disgorged, they are left in the bottle and help create the unique taste and mouthfeel found in Pet Nat
The ‘artistic’ interpretation of this winemaking method largely identifies around the role of SO2 and of yeast. Advocates of Natural wine (that includes Pet Nat) support the idea that adding higher amounts of SO2 in winemaking reduces the inherent characteristics of a grape and its terroir. Terroir is made up of all elements of an environment that can have an effect on the final taste or structure of a wine. This is ultimately the base for what makes a wine unique. The winemaker or oenologist then adds their own flair and style to what nature has given them in collaboration with the viticulturist.
The other piece of this interpretation concerns the subject of yeasts. Yeasts are a microorganism that naturally occurs on the skin of grapes. A healthy ecosystem typically yields a richer quality of yeasts, which is in part why Natural winemakers require organic or biodynamic grapes to make their wines. Higher levels of yeasts in organic and biodynamic vineyards make for a smoother fermentation process without the need to add prefabricated yeasts. Prefab yeasts are typically high-quality and most often come from fancy labs in France and California. However, with any lab-made or mass-made product, there is an absence of individuality. Wineries that vinify using only natural yeasts typically have high confidence in the health of their surrounding ecosystem. Additionally, they believe that natural yeasts are a part of what makes their wine taste like it is from the Russian River, from the Loire, or from Chianti, etc. We call this a “sense of place”, and Pet Nat has it in spades.
If you ask a winemaker, Pet Nat was historically made as a beverage for the staff; something designed for short-term consumption that rarely left the winery. Even today, it’s made in tiny quantities (rarely will you find production over 500 cases made per year) which is one of the reasons that it can be difficult to get your paws on the good stuff. The producers are passionate folks who have been doing this for a long time - often across multiple generations. They are farmers. Understanding this is a critical part of appreciating Pet Nat and will hopefully help you to recognize why this wine is so special. The majority of producers use only their own estate organic or biodynamic grapes and won’t employ corrective methods in vinification if Mother Nature deals them a bad hand. The overwhelming majority of these producers have no marketing department and no advertising budget. One of the things I love most about Pet Nat is that it really isn’t a CPG product; it’s an agricultural product. Don’t worry about any funky additives here. Just like anything else you buy directly from a farm, what you see is what you get.