Col fondo

Col fondo means “with the bottom” in the dialect of the Veneto hills. It is the older, rural face of Prosecco: refermented in the bottle rather than in a pressure tank, undisgorged, cloudy, with live yeast resting on the bottom. Producers like Casa Coste Piane (Loris Follador), Costadilà and Bele Casel pushed the style onto international wine lists during the 2010s, carried by the Italian natural wine movement around Vinitaly Resistente and VinNatur.

The technique

Glera is vinified into a still base wine. In spring, often timed to the first lunar cycle for biodynamic makers, the wine is bottled with residual sugar from the harvest or with grape must. Fermentation restarts inside the glass. No liqueur de tirage with cultured yeast and sugar solution as in Champagne, no autoclave as in standard Charmat-method Prosecco. The wine stays on its lees until the bottle is opened. Pressure usually ends up between 2 and 3 bar, lower than regular Prosecco. The glass arrives slightly cloudy, or the host deliberately leaves the sediment in the bottle.

The legal layer since 2019

This is where things get awkward. The Consorzio Conegliano Valdobbiadene formally allowed col fondo inside the DOCG rules in 2019, branded as “Sui Lieviti”. The conditions are strict: at least 90 days on the lees in bottle, no filtration, mandatory label declaration. Wines without DOC or DOCG that call themselves “col fondo” sit outside that framework and can technically be made differently. A bottle labelled Conegliano Valdobbiadene Prosecco Superiore DOCG Sui Lieviti is not the same product as a hazy IGT Veneto with col fondo written on the front.

A critical observation

Marketing around col fondo sells the image of unbroken tradition that simply survived. That story holds for a handful of families, but the visible boom is recent and commercially driven. When pet-nat took off in Brooklyn and Berlin, the Veneto realised its own old variant could fetch premium prices. The 2019 DOCG regulation is not a return to roots, it is the legal containment of a trend. Buyers who pick up a cloudy bottle without the DOCG mark often assume something different from what is actually inside. Read the label.

Key producers

Casa Coste Piane (Loris Follador) is the historical anchor producer in Valdobbiadene, with col fondo in the family since the 1970s. Costadilà (Ernesto Cattel) has produced ancestral versions since 2006. Bele Casel follows comparable practice. Malibran and Sorelle Bronca run medium-sized productions. Outside Veneto there are a few Friulian and Slovenian col fondo versions, but Glera remains the anchor grape and that grape grows almost exclusively in Veneto and Friuli.

In the glass

Pour col fondo carefully to leave the sediment in the bottle, though some drinkers deliberately keep a portion of it back for a rustic finish. In the glass it shows cloudy gold-green, with green apple, white pear and a bready note from the yeast lifting off a herbal edge from the skins. The palate is lively and fresh, unpolished, usually dry in a brut nature sense with no perceptible sweetness. Pressure runs lower than Charmat Prosecco, often 3 to 4 bar instead of 5 to 6, so the mousse feels softer. Drink it cold, around 6 to 8 °C, with fried seafood, Venetian cicchetti, salami with vegetables, or goat cheese with honey.

Difference with pet-nat

Col fondo and pet-nat overlap technically: both use second fermentation in bottle, both typically remain undisgorged, both carry living yeast. The difference sits in geography and grape: col fondo is almost exclusively Glera from Veneto, pet-nat covers any grape worldwide. For the drinker looking for regional style: col fondo is recognisably Venetian, pet-nat is a world category without a single regional pattern. Both are legitimate expressions of méthode ancestrale, each with its own identity.