By Kevin Kourofsky
“Sometimes you have to be like Luke Skywalker, throw the instruments away and go by feel.” Quotes by Phil Plummer
Phil Plummer held the bottle warily at an arm’s distance as one might hold a stink bomb that might explode at any time. He carefully lifted up the crown cap on one side, then the other and then the other side again. He explained that he brought to the lecture some purchased pét-nats along with his own wines and he did not know these makers. He explained that pét-nats can be unpredictable and can gush or fly out of your hand on opening. If not made carefully, they can launch themselves like a Saturn V rocket. But these were well behaved pét-nats and all that occurred was a pleasing sssssh.
Phil was giving a talk on natural wines and pét-nats at the New York State Home Winemakers Seminar in June 2023. Phil was the perfect choice as he is always on the cutting edge of the industry. Phil has been making wine in New York’s Finger Lakes region for over a decade, spending the bulk of those years at Montezuma Winery, where he has served as head winemaker since 2013. Phil has also taken the lead in the development and production of a wide-ranging portfolio of wines made from grapes, fruit and honey, and was instrumental in the launch of Montezuma’s sister wineries Idol Ridge and Fossenvue. He is also a contributor to WineMaker Magazine.
Pét-nat is a pet name for pétillant naturel one of the fastest growing categories in the wine world, especially amongst those who like craft beers, including sour beer, and cloudy hard ciders. It’s a sparkling wine made in the méthode ancestrale, the original sparkling wine method. It is more unrefined than the clear and elegant Champagne we all know.
The word pétillant derives from the French and is usually translated as sparkling, as would seem evident. But the French word pétillant is not the usual word for a foamy wine which is mousseux. Pétillant also means crackling as well as sparkling, like the embers of a fire and that certainly describes a Pét-nat.
Sparkling wines in the Champagne style are made in the méthode traditionnelle starting with a base wine finished at an alcohol level of about 10 or 10 ½ %. The wine is gently clarified and may be aged before being re-inoculated after additional sugar is added. A second fermentation occurs in the bottle. The added sugar determines the final pressure and alcohol level of the wine. After this second fermentation and after further aging on the yeast, the yeast is removed by gathering it at the cap-end of the bottle and freezing the yeast. The pressure within the bottle clears the yeast out when the crown cap is removed. The wine is then given its distinctive cork and wire cage. Nothing could be simpler, except everything about it!
Pét-nats go through one continuous fermentation starting in a usual fermentation container and finished within a champagne style bottle. As part of the natural movement, they are made in a low or no interventionist style and are meant to be lower in alcohol and with moderate to low fizziness. Think frizzante. They are usually a bit rustic, unexpected and perhaps with a lure of danger. With the help of expert winemaker Phil Plummer, in this article we’ll explore together how this style can be made by the amateur winemaker without expensive equipment and with the lure, but avoiding actual danger.
Natural Wine versus Modern Winemaking
“I don’t know a single interesting person who doesn’t have a flaw. Wines are the same.”
Pét-nats fall under the umbrella of ‘natural wines.’ That’s a very large umbrella and the term has become confused. Generally it’s thought that a natural wine is one where the grapes used are grown organically or bio dynamically, intervention is nil or at a minimum, and fermented with wild yeast. But really there is no one accepted definition of what constitutes a natural wine. Winemakers now generally accept that this category is on a spectrum, from low intervention to the hardcore category of ‘zero-zero’ wines. In that category, nothing is added and nothing is subtracted. But what is an addition? Is fruit selection an intervention? What about heating or cooling the must? Are even minute amounts of stabilizing sulfites allowed? Luckily, we amateur winemakers can do as we choose, subject only to the law of common sense. We don’t need to create an indigenous fermentation or risk off aromas by forgoing sulfite completely. In fact, Phil strongly recommends that amateurs use a commercial strain of yeast. And unless you are in the zero-zero category, low intervention winemakers use sulfites, though in low amounts. Don’t let the ‘woo’ and ‘magic talk’ stop you from trying this exciting method.
Making Pét-nat
“You have to babysit these wines. You have to hang out with these wines. You have to listen to them. Observe rather than force.”
What You Need
Most of what you need to make these wines you already own if you are a winemaker. A hydrometer is crucial as are very sturdy champagne style bottles with very strong crown caps. You will also need a capper that can affix these caps. Safety equipment, such as eye and hand protection is also recommended. A strong fermenting yeast is also a must (This a low intervention article and no pun was intended).
A core decision is the grape varietal. This is an area where acidic varietals are necessary. Low tannin is also suggested, as tannin becomes aggressive when the wine is served chilled. This is an area where Hybrids shine. Phil’s favorites are Catawba, Diamond and Marquette. Iona and Vidal Blanc may work well. Don’t count out Riesling or Sauvignon Blanc, both with citrus and floral aromas and bracing acid.
Gauging the remaining sugar left in the fermenting wine at bottling is difficult, thus the exact amount of pressure in the champagne bottles may be stronger then calculated. These bottles will need to be strong. They must have a push up, called a punt. This is a deep recession in the bottom of the bottle that should fit most of your thumb. This gives the bottle the strength to hold up to 6 atmospheres (ATMs) of pressure, (a tire holds 3 ATMs). I reuse bottles of sparkling wine I’ve purchased, as ones sold to the amateur are often good only for a very light pressure. Also be aware that Europe/Australia use bottles with a larger neck and opening. These won’t fit US caps.
Champagne style caps are different from most beer caps as they hold higher pressure than beer and much more acidic wine. Seek out crown caps that are made for sparkling wine. They may be made of stainless steel, but not necessarily so. You will see a thick silicone sealing ring and not light, foamy plastic that some cheap caps are made with.
Many times capping machines have two plates, one for beer caps and one for champagne caps. Double check before you buy.
Unless you are zero-zero, you’ll need yeast. Phil strongly recommends EC-1118 for reasons discussed below.
To track residual sugar you’ll need a hydrometer and perhaps a Clinitest kit. A refractometer can’t be used, unless you’re a wiz at math as the alcohol in the wine will disrupt its reading. There is a formula you can use to account for the alcohol, if you insist. Good luck with that.
Safety equipment is important as pét-nats can be unpredictable. He uses eye protection and Kevlar gloves. Sturdy clothes or aprons would be in order. Let’s respect the power of all sparkling wines.
Beginning the Journey
Having gathered all you need, the next step is fermentation. If you are dealing with cool climate grapes or ones that have low sugar and high acid, you may make a low intervention decision and you may not need to adjust either. However if the sugars are high, that may not make for a good sparkling wine and may be difficult to bottle. If you wish to be zero-zero, there are no decisions to make.
Phil suggests the amateur winemaker use a commercial yeast to avoid the difficulty of an indigenous fermentation. Also commercial yeasts, especially Phil’s preferred yeast EC-1118, provide more flexibility and safety. EC-1118 is a strong fermenter and is often used for sparkling wines. You can also chill the juice during fermentation to slow the end point where bottling is necessary, which may occur at two in the morning. You can guide the fermentation to a bottling time that works for you. Another benefit, according to Phil, is that it will react to pressure in the bottle and stop fermenting at 6 atmospheres, the limit of a strong champagne style bottle. If your sugar calculations are off, you may have some residual sweetness in the wine, but you shouldn’t have an exploding bottle. He warned that that is not true of all yeasts, especially QA23, as he learned at his cost.
All fermentations need nutrients and oxygen. The addition of organic nutrients, such as Fermaid O, may avoid a reductive quality in the finished wine. Again, that is an intervention call.
Gushing Prevention
Gushing is the unfortunate spewing of the bottle’s contents and can occur in any sparkling wine for two reasons besides not chilling the bottle properly. One is too much pressure in the bottle and a second is tartaric acid crystals in the bottle. The crystals act as an irritant causing foaming.
Phil partially disgorges his pét-nats to assure the pressure is even across the bottles, with no surprises for his customers.
To avoid the crystals, he cold stabilizes the fermenting wine. EC-1118 is a flexible yeast and it can hibernate when subjected to cold temperatures, then can restart when warmed. Unlike still winemaking, you can chill the wine then allow it to warm to finish the pre-bottling fermentation. The fermentation is not stopped, only interrupted.
The Tricky Bit
Pét-nat fermentation must be constantly monitored to determine when the ongoing fermenting wine is bottled. You want just enough sugar to create a nice sparkle in the finished wine. A hydrometer can be used, checking for the amount of residual sugar. The fermentation finishes in the bottle creating CO2 bubbles we all enjoy. Generally, the yeast is left in the bottle, unlike Champagne style sparklers. The amount of yeast can be reduced by disgorging, or partially disgorging some of the yeast.
When the sugar levels drop sufficiently, Phil chills the wine to slow the process. It’s like slowing down on the expressway exit ramp. Phil suggests that the wine be bottled when the wine contains 2.5% Residual sugar (RS). RS is a percentage of sugar and is not directly correlated to Brix or Specific Gravity (SG). RS is expressed in grams per liter (g/L). A wine with a 0.1% residual sugar is considered dry and is 1 g/L or about 1/8th of an ounce of sugar per liter. A wine with 1.0 is ten times that and would be a sweet wine. One Brix is defined as 1 gram of sugar in 100 grams of liquid. From your hydrometer, you need to calculate the total brix per liter and convert to RS. Or if you’re like me, whose math is not to be trusted, use an online calculator such as vinolab.hr or winebusiness.com.
Keep in mind that every 0.4% RS (4 grams per liter) equals one atmosphere of pressure. So, Phil’s 2.5% number is close to the 6 ATMS limit. Perhaps 5 ATMS should be a maximum for an amateur. A more cautious number might be 1.5% RS, or about 4 ATMs. That’s a very respectable fizz and in keeping with the low alcohol profile of pét-nats.
It’s also very important to account for the still trapped CO2, particulate matter and alcohol in the wine when using a hydrometer. You may want to rack the wine and stir the sample before testing. Then pass the sample through a coffee filter to clarify. The alcohol will also skew the results. Phil warns that you should consider that there is a likelihood that the sample contains 1% RS more sugar than your reading. That would be about 10 g/l or 1 brix.
Clinitest kits can be a big help as they read in RS percentages. But they were not made for wine and you must follow the conversion directions carefully.
If you are very low to no intervention, wild yeasts can still be robust, so Phil recommends that if you are using a wild fermentation, your RS number should be on the lower number just to stay on the safe side.
I also reached out to a winemaking friend for advice about how he makes his pét-nat wines. He won a double gold for his pét-nat at an AWS amateur wine judging a few years ago. I had the pleasure of tasting his sparkler and I was pleasantly surprised at how enjoyable it was. He explained he took advice from a family with a long history of making pét-nats. Their process was to adjust the juice to 21 brix, about 12% potential alcohol, and ferment to dryness. They picked up their cool climate juice in October and allowed a lengthy fermentation through the following April. They then bottled, adding a teaspoon of sugar and no additional yeast. The wine he said, had “plenty of bubbles and some nice pressure” with no popping bottles. He tells me those winemakers have gone a little lower-intervention by not adjusting the juice before fermentation, but they now add a “heaping” teaspoon of sugar. This seems to be a hybrid method, not really a Champagne style or a continuous pét-nat style, but a great practical compromise between the two. It certainly tasted to me like a full, clean pét-nat!
Either way, you may want to consider some slight SO2 very early on to avoid malolactic fermentation or spoilage, but NOT at bottling. You would want almost zero at that point as it inhibits fermentation especially under the stressful conditions in the bottle.
“The only way to figure it out is to figure it out!”
When Phil finished his talk at the seminar, I could sense an air of excitement in this normally reserved crowd. Here was something new and different, perhaps bringing back memories of one’s early days of winemaking. Part of the joy was in the doing, but also in the figuring it out. If you are feeling a bit jaded about your winemaking-been there, done that sort of feeling-then this new style of winemaking may be a way of putting some fun into your winemaking. Make pét-nat, why nat?
Kourofsky Wine 