Secondary Fermentation in the Bottle


I do not wish to appear argumentative with those who appreciate and support the “sur lie” type of wine.

Each one to his own taste. However, I would like to make things a little clearer as far as this type of wine, called either “sur lie” or produced by secondary fermentation in the bottle, is concerned. I’m interested not so much about which name to choose but about the actual facts.
Does the “sur lie” (col fondo) type represent or not the old or traditional Prosecco as many continue to uphold? You only need to go into the few bars left in our territory to learn that Prosecco used to be drunk in the still version, served from the demi-john into the litre, half-litre or quarter-litre carafe. The tradition of the farming community must be duly recognised in that wine without bubbles. The few elderly men that can still be found talking for hours and hours sat at the table in the bar drink only that type of wine. It’s rare to see them drink a semi-sparkling wine and even less one “col fondo”. Right up until the fifties, when secondary fermentation in autoclave/pressure tank slowly took hold and gradually became the most popular technique in the territory, farmers’ and workers’ families drank still Prosecco.

At the same time that sparkling wine became popular, rural folk began to bottle the still Prosecco for daily use. There was absolutely no intention to obtain secondary fermentation, but it occasionally happened that a slight sugar residue had remained which caused spontaneous fermentation once again in the spring. This process, which originally occurred by chance, was slowly guided and controlled by man. The habit spread amongst farmers’ families of bottling the still Prosecco with added sugar in spring so as to be guaranteed the sought-after and satisfying bubbles. That is the history of “sur lie” or “col fondo” Prosecco. Nothing more and nothing less than sparkling Prosecco.

Understanding whether this type of wine enhances the vine variety and the territory or not is another matter and in my opinion, the most important. When drinking a “col fondo” Prosecco, rarely or only by sheer chance do you remain fully satisfied. For the moment I do not wish to dwell on the skill of the producer in presenting a genuine, straightforward and pleasant wine, but will talk about the character in general of the “col fondo” type and more specifically about its negative and somewhat degrading effects on the Prosecco variety.

Although there are some vine varieties which are enhanced by and benefit from this method of production, such as Lambrusco, Prosecco on the other hand cannot fully express itself as the yeast flavour is overriding and makes the wine flat. Its delicate varietal aromas are generally absorbed and transformed by the commonplace malolactic fermentation, which occurs immediately after the alcoholic fermentation in the bottle and often generates off-odours and makes the wine unpalatable. The presence of yeast sediment in the bottle and especially if it is disturbed upon uncorking the bottle so that it becomes suspended in the wine, alters the original flavour, giving it a sweetness that reduces perception of its more interesting acid and savoury sensations. For me this type of wine is not stable, it is too susceptible to change due to the presence and continuing work of the yeast.

Its presence in the bottle serves to transfer substance to the wine, to make it harmonious and help it become well balanced. Disgorging therefore becomes an equally important passage, with which the wine starts a new phase of ageing and development. The wine’s true characteristics become clear at that moment. Without yeast the wine can prove its worth, without elements that could spoil it the wine can finally start its journey towards maturity, the ageing process common to all living beings. And a wine that ages well will be a great wine.
For Prosecco the Classic Method allows the expressive character of the wine to be explored unlike the Charmat and even less the “sur lie” (col fondo) method.