Perhaps you are familiar with ‘flash detente’. If you are not you should read our book The Creation of a Wine (A Wine is Born, unfortunately not yet available in English – Ett vin blir till). Basically, it is a method to extract more from the grape skins by heating up the grapes and then rapidly subjecting them to a vacuum. It is a big machine sold by Pera.
Another big vinification equipment manufacturer, Bucher-Vaslin, has now invented another process which is different but that does essentially the same thing: Delta Extractys. It uses high pressure instead of low. After heating the grapes to around 60 degrees C (in e.g. a thermo-vinificator) they are transported to a pressure chamber. The grapes are put under high pressure, up to 4 bars, and then rapidly returned to normal atmospheric pressure.
The effect is very similar to what happens in flash detente: the grape skin membranes are damaged so that the extraction of polyphenols is more intense. It supposedly increases the fruit and body of the wine and gives them a better tannic structure. Most likely to be used by cooperatives and other large producers of not too ambitious wines. And not cheap: 35,000 to 90,000 euros. (Source: La Vigne, Bucher Vaslin).
