How wine is born: dry ice and Alfero

Often, on the technical datasheets of wines, we see the words “dry ice” and only by Googling do we learn that this is actually CO2 in its solid state.

It has been used in winemaking for a few years now, primarily to cool the grapes immediately after harvesting and then in the cellar.

I’ve been using it for my Pinot Nero Alfero since 2006, to obtain a gentler, more feminine and balanced wine.

Now let me explain how and why I decided to spend 400/500 euros for a tank with a capacity of just 3.5/4 tonnes of grapes.

I add it during pressing.

When it comes into contact with the must, dry ice sublimes, subtracting heat and producing CO2.

In just a few seconds, the temperature can drop from 30°C to 5°C for example.

The thermal shock causes the vegetable cell walls of the grape skins to tear.

This makes it possible for me to extract colour (anthocyans), perfumes and aromas after just a few days, avoiding the marked extraction of tannin as a result of the solvent action of the alcohol.

The CO2 produced as the grapes are drained to draw off the must saturates the tank, taking the oxygen that could oxidise certain composites during the initial latent pre-fermentation phase, with it.

The end result is more respect for the raw material and more moderate extraction of tannin, reflected in a finer, more elegant wine.

All we have to do is taste it, now in malolactic fermentation.