With the arrival of the wet Autumn weather, the Cabernets are struggling to ripen (most Merlots are in) and rot is setting in. Potential is there (particularly for the Merlot); colour looks good, intense aromas of black fruits, freshness from the cool nights. The last of the cabernets are being harvested int he Medoc and Graves (good luck!) . Final days of harvest, harvest festivals to celebrate in this difficult ‘winemaker’s vintage’.
The real work now starts in the winery to gently extract the colour, flavours and tannins from the un-uniformly ripe skins and pips. The decision of when to stop maceration is going to be crucial this year to not get any green flavours.
The yeasts are busy at work and the grape juice is being transfered into wine (the production of CO2 gas makes work int he winery hard-going) – no problm this year for fermentations to get going - and finish!
Gentle extraction of the colour, flavours and tannins from the skins is done by gentle pumping over at the beginning of the fermentation process when the extraction is soft as it is water and not alcohol that does the extraction of the skins. Also the use of a gaz stick (using inert C02) enables gentle extraction by breaking up the cap of skins with gas, it performs in a few seconds what pumping over does in several minutes – but more gently. The must-have tool of this season!
As the juice turns into wine the sugar levels fall and turn into alcohol. The vats are tasted constantly (by the producers and their oenologist consultants in the labo) to determine the type of treatment needed to extract; the temperature to be used, how many pumping overs etc.
Delestage was performed on each vat before the juice turned into wine (at around 1060° density). It involves the pumping of the juice into an empty vat leaving behind the cap of skins. This is done from the bottom of the vat so the pips are removed also as they lie at the bottom of the vat. The juice is then repumped on the top of the cap to extract the skins and to break it up (during pumping over the wine tends to take the same channels through the cap). The secondary function of a delestage is the removal of the pips, very important for this vintage.
As you can see this year the pips are a bright yellowy green colour. Every year the number of grapes and the health of the grapes is set for the following year during the flowering period. That is the spring of 2011 set the grapes of 2012 (not the spring of 2012). This is called the ‘induction florale’. During the spring of 2011 the conditions were so favorable that the grapes produced three or four pips in each grape rather than the normal two pips. What this meant this year is that as the grapes swelled some of the pips became detached inside the grape (that is they stopped receiving nutrition). This meant that they stayed in that state and did not ripen further, staying yellowy green rather than turning brown. It is important this year to try to remove these unripe pips and not extract their green tannins.
Once the juice becomes wine, this year there is very little pumping over to be done, only the wetting of the cap (which sinks into the wine as there is no more C02 gas to push the cap upwards).