At Mumm Napa, we have some strong ideas about what separates a memorable sip of sparkling from an ordinary one—it all starts with winemaking technique.

Steeped in Tradition

It really comes down to our method—or méthode, if we’re being proper. Mumm Napa sparkling wines are made using an intricate process called Méthode Traditionnelle—the same time-honored approach used to make French Champagnes. In the video below, our head winemaker Ludovic Dervin talks you through the 13 steps behind the making of each sip, lending his authentic French accent to describe Old World techniques we’ve perfected here at Mumm Napa.

Watch: An Introduction To Méthode Traditionnelle 

Step One: In the Vineyard

Mumm Napa grapes are grown in the cooler regions of the Napa Valley under the meticulous care of our growers. Every sparkling wine crafted with the Méthode Traditionnelle is made from the classic primary varietals Pinot Noir, Chardonnay, and Pinot Meunier—just like in the Champagne region of France.

Step Two: Harvest

How our grapes are harvested sets the tone for the winemaking process. Harvest marks the end of the year and starts a new cycle in the cellar. We harvest earlier to dial down grapes’ sweetness, selectively harvest by blocks to make sure the grapes are ready, and carefully (as in, gently) hand-pick and transport to prevent bruising and bring the best quality grapes to the presses.

Step Three: Pressing

Only whole clusters of grapes are pressed, slowly and gently to extract the most delicate and fresh juice and preserve freshness. The first press is known as the cuvée, while a second and third press results in the “taille”—juice with less acidity and more tannin.

Step Four: Fermentation

Freshly pressed juice is fermented right away at cold temperatures—most often in steel tanks, while a small percentage may be fermented in traditional oak barrels. During fermentation, yeasts convert sugars into alcohol and carbon dioxide, resulting in a base or “still” wine.

Step Five: Assemblage

The most artistic part of the process is sometimes called “The Winemaker’s Expression.” During this stage, winemakers taste from 80 to 120 different individual base wines to carefully craft each blend. The result reflects the winemaker’s distinct vision for each wine, whether it be retaining consistency from year-to-year (as with Brut Prestige) or developing a unique expression based on a particular year’s crop (as with Devaux Ranch).

Step Six: Bottling (Or, Fermentation, Take Two)

Mumm Napa winemakers carefully introduce a small amount of pure, fine cane sugar and yeast into the blend, and then place it in thick glass bottles that are sealed with a bidule and a crown cap for secondary fermentation.

Step Seven: Bottle Aging

During the secondary fermentation, the yeast works its magic, producing alcohol, flavors, and carbon dioxide. Now, with the bottle sealed, the carbon dioxide cannot escape. As it infuses into the wine, the bubbles emerge, and—voila! You can see why we call this stage prise de mousse, or literally, “capture the sparkle.”

Step Eight: En Tirage

The process of “on the yeast” aging adds more creamy flavors and toasty aromas. The longer the wine remains in this stage, the more rich, delicate, and creamy the wine.

Step Nine: Riddling

This involves the gradual tilting of the bottle down while rotating slightly in increments. With all that yeast multiplying during fermentation, some sediment—or “lees,” as it’s known—remains in the bottle. Riddling is the removal of lees from the wine. It releases proteins and molecules that transform the wine flavors from mere fruitiness to multifaceted nutty and creamy flavors.


Step Ten: Disgorging

We eliminate the yeast deposits that have collected in the neck of the bottle by freezing the top portion of the wine. Then we unseal the bottle to allow the pressure to eject the yeast and leave behind only a perfectly clear wine.

Step Eleven: Dosage

The sparkling wine is finished with a blend of cane sugar and reserve wine, which will determine the wine’s ultimate style and personality. It is the final artistic touch of the winemaking craft, and defines the final style of the wine, from a dry brut to a lightly sweet demi-sec.

Step Twelve: Adding the Cork

The bottles have their corks inserted, wired, and put to rest for several months to recuperate from disgorging, and to allow the dosage wine to fully integrate. The bottles also receive their signature Mumm Napa label.

Step Thirteen: Cellar Aging

Most sparkling wines are ready to drink, but they will age gracefully for at least five years. Some premium wines will age 10 to 30 years.

Extra Credit: Popping and Toasting

The meticulous method behind the bubbles is not without purpose. Taking care to follow process while leaving room for a winemaker’s personal style is what introduces unforgettable, award-winning, remarkable vintages into so many occasions. The next time you raise a glass, you can do so knowing many little details went into those deliciously tiny bubbles.