Definition: Carboglace

Carbon dioxide ice or dry ice

This ice has the unique property of changing from a solid to a gas without passing through a liquid state, making it ideal for cooling grapes.

It is used to protect the harvest from heat, to prevent the wine from coming into contact with oxygen, and to control the temperature during skin maceration or cold maceration. This technique is said to give the wine more fruitiness, suppleness and colour.

Carbonic snow at minus 80°C is used during the harvest to intensify the colour of the wine. This is the latest trend among prestigious châteaux. Every year during the harvest, lorries deliver large coolers filled with carbonic snow at minus 80°C, which is added to the harvest before maceration. The result is surprising: wines with an almost inky colour (black as ink). This technique dates back to the early 1990s and has been a huge success in Bordeaux and Burgundy. According to Carboxyque, the only French manufacturer, sales are increasing by 25% each year (300 tonnes/year in 2002). The effect on colour is unanimously recognised. However, its influence on aromas and tannin quality is still being studied. The aim now is to compare it with traditional pigeage or remontage techniques. It is clear that this technique allows the temperature of the must to be lowered to levels never before achieved with coils, i.e. 10°C and down to 5°C. The wines are darker, with a noticeable improvement in aroma and taste. Skin compounds are extracted, which add body to the wine. Is there a risk of moving once again towards the standardisation of wines? It would appear not, as the subsequent fermentation plays its part. Others say that this method will not catch on because it is too expensive. It takes 600 grams of dry ice to cool 100 litres of wine by 1°. For example, for an 8-hectare estate, it takes up to 2 or 3 tonnes at an average of £3 per kilo of dry ice. The bill is enough to cool the customer.