One of the most unique wine tours in Piedmont is in the dark, cool corridors of the Underground Cathedrals to taste a glass of sparkling Moscato d’Asti or—an up-and-coming gem of the area—the Metodo Classico of Piedmont.

In Canelli, a town located at the border of Monferrato territory before the hills become the Langhe, there is more than meets the eye—literally. Deep under the earth, corridors and caverns house millions of bottles of bubbly in what are called Underground Cathedrals. They stand as a monument to the very beginnings of Italy’s sparkling wine production.

The Underground Cathedrals, recognized in Piedmont’s UNESCO World Heritage Vineyard Landscapes of the Langhe-Roero and Monferrato, probably began to be excavated starting in the 18th century. People began chipping away at the volcanic tuff rock underground for natural cellar storage space. The tunnels’ expansion really took off in the 19th century, right around the time when Canelli began to be known as the “capital of spumante” for its production of sparkling wines Moscato d’Asti and Asti Spumante. And today, another bubbly is experiencing renewed consumer interest, giving the city its right to keep its epithet: dry Metodo Classico made from pinot noir and chardonnay.

Italy’s first sparkling wine

Vintage promotional poster

Vintage promotional poster – © Creative Commons

In the 1850’s, Piedmontese winemaker Carlo Gancia visited Champagne. He was so enamored with their sparkling wines that he returned to produce his own from moscato, a wonderfully aromatic grape that has grown in profusion in the area since at least the 1300s. And, just like champagne of the days of old, it was sweet! Few people realize that champagne began as a sweet wine as opposed to the dry wine it is today. Hence Gancia’s intuition to use moscato, a grape that’s naturally high in sugars.

Winemakers, in fact, had already been dabbling in sparkling wine production in the area. Initially, it was so difficult and dangerous that they wore sturdy leather aprons and screened face masks to protect themselves from spontaneous explosions. This was because of a unique sparkling winemaking method that today is no longer used: the wine was bottled before its sugars were used up, which meant alcoholic fermentation continued inside the bottle…building up pressure that was often too much for the quality of glass to withstand.

Gancia was the first to produce sparkling wine with consistency, utilizing techniques he learned in France. The French’s production was more established than Italy’s newly blooming bubbles, and greatly reduced bottle explosions. Gancia produced Italy’s first “official” sparkling wine in 1865, the sweet “Moscato Champagne.”

Later, glass-making techniques improved, winemakers honed their skills and understood when the ideal moment to bottle was, and cellar masters could take down their “Hazardous workplace” signs with a sigh of relief.

Two methods of making bubbly

Canelli was nicknamed capitale dello spumante, or capital of spumante, for its national and international importance in producing first Moscato Champagne, and later Moscato d’Asti and Asti Spumante. Although the quality of Asti Spumante took a turn for the worse around the 1980s-90s, it has been on the rise again; and its popularity was only possible through another (half-)Piedmontese invention, the Martinotti-Charmat winemaking method.

There are two universally used ways to make sparkling wine: 1) the champenoise method (also known as Metodo Classico or traditional method); and 2) the Martinotti-Charmat method (often just “Charmat”).

Neck of a bottle of spumante metodo classico

Neck of a bottle of spumante metodo classico – © Francesco Margutti

The champenoise method requires much more hands-on work, time, and space for higher quality sparkling wines, thus making it much more of an investment. After the grape must has fermented, the still wine is bottled and given an additional dosage of sugar and yeasts, or liqueur tirage, to create effervescence—this is called secondary fermentation. It’s why the bottles rest in those A-frame racks called pupitres to collect the dead yeasts, or lees, at the cap so that they can be disgorged, or expelled (otherwise the wine would be foggy!).

The Charmat-Martinotti method is quicker and less costly. It forgoes the secondary fermentation altogether; instead, the wine undergoes alcoholic fermentation in stainless steel autoclaves, where it develops its effervescence naturally, and is then stopped using cold temperatures before being bottled under pressure. This method was invented and patented in 1895 by Piedmontese Federico Martinotti and developed by French Eugène Charmat in 1907 for industrial production. It’s how the off-dry Asti Spumante is made, which has about a 9% alcohol level. The sweet Moscato d’Asti is also made this way, except its fermentation is stopped earlier, thus leaving a higher amount of residual sugars and about a 5% alcohol level. And, if you’re wondering, yes: it’s also how the famous Prosecco is made!

Inside an autoclave

Inside an autoclave – © Francesco Margutti

False natives of Piedmont, and the next generation of bubbles

Moscato, an aromatic grape variety, could be called a “false native” of Piedmont. It has been grown in the region since at least the 1300s, but once upon a time it was imported from ancient Greece to Italy, finding its perfect soil and climate in the Monferrato. In fact, today’s certified territory for producing Moscato d’Asti DOCG was already unofficially delineated in 1895: “A series of townships belonging respectively to the three regions of Astesana [Asti], Alto Monferrato, and the Langhe together make up a zone that has every right to be called the ‘zone of Moscato.’” (Il Moscato Canelli by Arnaldo Strucchi, Carlo Gancia’s enologist)

But moscato wasn’t the only variety that caught the attention of winemakers at the crux of the 19th and 20th centuries. In the early 1800s, Piedmontese Marchese Filippo Asinari had imported cuttings of chardonnay and pinot noir from France to the hills of Monferrato. There they happily, vigorously took root. While these varieties are still not seen as indelibly “Piedmontese” like moscato, they’ve been present for 200 years and have likewise found the climate and soil to be ideal.

And these two varieties continue to impress. In the past decade, there has been an increase in production and interest for dry metodo classico wines made from pinot noir and chardonnay in the Monferrato and Alta Langa (“high Langhe”) hills with a quality, in its best versions, to match that of Champagne. Like France’s famous bubbles, the Piedmontese metodo classico wines are made with a higher percentage of pinot noir than chardonnay and display a remarkable complexity, structure, marked minerality, and longevity. Keep your eye on this class of bubbles as it begins to make a name for itself as a sparkling wine per eccellenza.

Wineries and more below the earth: open for visitors

As sparkling wine production grew exponentially and the wineries of Canelli grew larger, becoming the internationally-known names they are today—Coppo, Gancia, Bosca, and Contratto to name just a few—the corridors and rooms expanded, chink by chink, to house more wine. Why this fixation with expanding underground? Tuff rock is soft and so naturally lends itself to convenient storage space, but also, the temperature underground maintains a constant 12-14°C (54-57°F), ideal for wine. The Underground Cathedrals finally reached a depth of 40 m (130 ft.) and today account for a total of 18 km (11 mi) of underground space.

The old way to make the disgorging

The old way to make the disgorging – @ Courtesy of Coppo Winery

“Cathedrals” is an interesting choice of name for wine cellars. A cathedral is a place of solemn worship, of silence and contemplation, and even more than a simple parish church, they are majestic edifices built to inspire awe. And indeed, if you visit these deep corridors, which are not simply carved rock but are covered in brick and stone and formed of arches, softly-lit caverns, and walkways filled with barrels and pupitres, you will understand how their earthly majesty matches the incredible craftsmanship in above-ground, traditional cathedrals. They are similar, too, in their silence of the underground, in the echoes of large spaces, and in the long stretch of time it has taken to build them, like many of Italy’s most well-known and incredible Duomos.

Beyond the most famous names, there are hundreds of wineries that have their own subterranean cellars. They make for fascinating tours for wine tourists, but many tunnels are even used as offices and art galleries. The Regional Enoteca of Canelli has transformed their own tunnel into a striking restaurant. The Bank of Alba in Via Giuliani has a secured vault in the tunnel of their building, and the cellars of Reale Insurance, which contain a rare source of water, are used for exhibits and events.