Disgorging Pet Nat: Unveiling the Fizz with Style

Disgorging our sour wild plum and sage flower ambrosia.

About Pet Nat

Pet Nat, short for Pétillant Naturel, is a sparkling wine style that has gained popularity in recent years. Archaeological evidence suggests that it’s the oldest form of sparkling wine and was drunk by the Ancient Greeks and Romans. However, the earliest documented reference to sparkling wine is attributed to the Benedictine monks in the Abbey of Saint-Hilaire in Limoux, France, in 1531. They produced a sparkling wine using the traditional method of bottling wine before fermentation was complete, allowing the fermentation to continue in the bottle and creating natural bubbles. It was a style that became somewhat forgotten for a while, until natural wine producers in the Loire valley began to revitalise and popularise it over the last thirty or so years. Some of my favourite examples are made by tiny Loire valley producer Les Capriades and, from near the traditional home of Pet Nat in southern France, Domaine Plageoles.

Unlike more well-known sparkling wines produced using the Méthode Champenoise or Charmat methods, Pet Nat is bottled before completing its first fermentation. The result is an effervescent and naturally sparkling wine that captures the essence of the grape and the terroir or, in our case, honey, because we use the principles of making Pet Nat when fermenting and bottling our ambrosias. The final step sometimes undertaken in the production of Pet Nat is disgorging, where the sediment accumulated during fermentation is removed to reveal the clear and fizzing wine within (or, in the case of the video above, ambrosia). Below, we’re delving into the disgorging process of Pet Nat and its significance in crafting this unique sparkling wine.

What is Disgorging?

Disgorging is a critical step in the production of many sparkling wines, including Champagne, Cava, and some Pet Nat. During the initial fermentation of sparkling wines, yeast cells consume sugars to produce alcohol and carbon dioxide, creating the bubbles. In the case of Pet Nat, the wine is bottled before fermentation is entirely complete, allowing residual sugars to continue fermentation in the bottle, leading to natural carbonation. This process leaves behind a layer of yeast sediment in the bottle. Disgorging involves removing this yeast sediment, resulting in a clear and visually appealing wine.

Why Disgorge Pet Nat?

Disgorging serves several important purposes in the production of Pet Nat. It removes the yeast sediment, resulting in a visually clear and attractive wine. The process enhances the overall presentation and marketability of the Pet Nat. If you watched the video above, you would have noticed that the ambrosia we disgorged had a layer of lees that were released from the neck of the bottle which, though no doubt nutritious, doesn’t look very visually appealing to drink. If you’ve made a pet nat that was cold settled before bottling, you might not need to disgorge as there will likely be very little sediment. Ditto for many of our plain ambrosias, that are made just from honey and water, which also have very little sediment, so there’s not a lot to remove.

But for wines and ambrosias with a noticeable amount of sediment, disgorging can be useful in maintaining consistency across different bottles of the same batch, ensuring that each bottle showcases the wine or ambrosia’s intended characteristics. And for venues, it ensures consistency in serving, which is particularly important when selling a Pet Nat by the glass.

Disgorging Pet Nat

The process of disgorging Pet Nat is relatively straightforward, though it does need to be started in advance. Here's an outline of the steps involved:

1. Riddling: After the fermentation is complete and the wine or ambrosia has reached the desired level of carbonation, the bottles are placed upside down in racks, a process known as riddling or remuage. Over a period of time, usually a few weeks, the yeast sediment settles into the neck of the bottle. We don’t have racks, so we just turn our bottles upside down in their boxes at least a few weeks before we’re planning to disgorge.

2. Freezing the Neck: Once the yeast sediment has gathered in the neck of the bottle, it needs to be expelled. To achieve this, the neck of the bottle is dipped into a freezing solution of liquid glycol (-15C!) or (more commonly and more simply) the entire bottle can be placed in a freezer for 30-45 minutes, solidifying the sediment in the neck, since it’s the narrowest part of the bottle, so freezes the fastest. If you’re using a freezer to disgorge pet nat, try a couple of sample bottles first, to work out the right amount of time to leave your wine or ambrosia in there. If you’re in a warm climate it may need 45-60 minutes; if you’re in a cool climate or disgorging in winter, it may only take 30 minutes to freeze the solids.

3. Disgorging: The bottle is then quickly uncorked while facing slightly downwards, allowing the pressure within to expel the frozen sediment plug. The momentum of the gas and the sediment forces it out, leaving the clear and sparkling wine behind, and the wine is quickly tilted upright again (as shown in the video). Note that it can get pretty messy, so you don’t want to be doing this in your fanciest clothes. I also wear waterproof gloves if I’m disgorging a lot of bottles because I get cold easily, so they stop my fingers from going numb and clumsy.

4. Topping: After disgorging, there may be some loss of wine, creating a void in the bottle. To return the bottle back to its original volume and maintain pressure, a small amount of the same wine is then added back into the bottle before it is sealed again. You will need to use a crown seal or sparkling cork with a cage; even though there tends to be less pressure in a disgorged wine or ambrosia than prior to disgorging, it’s best to be safe and use bottles and seals designed for sparkling wine to avoid explosions.

Once your pet nat wine or ambrosia is disgorged, it doesn’t need any further ageing - it’s ready to go pretty much straight away. All you need to do is chill it down and enjoy. Sante!

Lou xo

References:

1. Gracie, C. (2019). What is Pet Nat? Everything You Need to Know About Pétillant Naturel. Wine Spectator. https://www.winespectator.com/articles/what-is-pet-nat-everything-you-need-to-know-57462

2. Larner, A. (2016). The Secrets Behind the Rise of Pét-Nat, Champagne’s Cool Little Brother. Food & Wine. https://www.foodandwine.com/wine/secrets-behind-rise-pet-nat-champagnes-cool-little-brother

3. Rego, S., & Gargiulo, L. (2019). Disgorgement of sparkling wine: physical aspects and influences. Beverages, 5(1), 10. https://doi.org/10.3390/beverages5010010

4. Keeling, S. (2017). Pét-Nat: The Wild Side of Wine. Wine Enthusiast Magazine. https://www.winemag.com/2017/07/19/pet-nat-wild-side-of-wine/

5. Ray, T. (2021). Wine: A Cultural History. Reaktion Books.