Although there are still few months till the next harvest, it is a perfect time to write about grape processing and bring back some memories from my first Bordeaux grape-picking, which took place a few months ago.
In general, after the grapes have been harvested, they need to be turned into wine. Grape processing is the first step of vinification when winemakers need to take care of after the harvest. In this process, the freshly picked grapes need to be processed and this depends on the style of wine that is being made.
I couldn’t stop myself to spend some time after the harvest on watching the winemakers’ team getting through the entire grape processing stages. My friend let me ‘do some work’, which literally meant I’ve processed about two boxes of grapes; it made me feel proud ;)
I used to think the machinery for this process is massive and takes a lot of space in the winery, but the one we were using was not, in my opinion, that big ;) Although it looked small, it can process about 40 tonnes of grapes a day!
Sometimes the whole grape processing machinery is the part of winery equipment, but mostly the machinery is rented for the harvest. To rent the size of the basic machinery we’ve been using is very cost effective and varies depends on the type of machine that goes with it, such as harvest machine or tractor. One day of renting the basic machinery cost approximately 1300-1500 Euros.
From the vineyard…
Grapes can be picked by hand or by machine. Sometimes after machine harvest, there are some rows that need to be harvested by hand as the machine cannot get there.
That happened in our case, as with the harvest team we visited a few vineyards to pick the grapes only from a few rows from each vineyard, where it was impossible for the machine to harvest, or where the vines were too young for the machine harvest.
Moreover, the harvest machine picks the berries only, leaving the stems on the vine. While handpicking, the whole bunches of grapes are picked.
After filling up the plastic boxes with grapes, the boxes were loaded carefully on a tractor and brought back to the winery.
… through the sorting table…
The grapes need to be processed as soon as possible after arriving at the winery. This is the stage of the process when berries are treated with the SO2; sometimes they are sprayed with the SO2 during the picking. The dose of SO2 depends on the quality of the fruit and it is a winemaker’s choice whether to use it or not and how big the dose should be.
Grapes we picked were very healthy and they had been treated only with a small dose of SO2 at the crusher.
We unloaded the boxes with grapes on the sorting table. The sorting table was automatic and worked on its own, vibrating the top table and eliminating any unripe or rotten grapes. Simultaneously, we have been sorting the grapes by hand, having a lot of fun while doing it.
… destemming and crushing…
After the sorting table, the conveyor was lifting the grapes to the destemming machine. Because the grapes were handpicked, the stems had to be removed and the process of doing so is called destemming. It is optional to destem grapes during the grape processing.
The destemmed grapes fall through the crusher and the must pump then delivers the crushed grapes to the tank, whilst the stems are removed separately from the end of the destemming machine to a massive plastic box and later loaded by hand on the tractor to be taken to the vineyard.
Crushing is another optional stage of grape processing. The crushing machine breaks the skins of the grapes and lets the juice freely run; that juice is called the free run juice.
While crushing, the special attention needs to be put on the pips so they become untouched. Crushing the pips is very bad for the wine, as crushed pips release the bitter oils that will make the wine taste astringent.
… to the tank.
After being crushed, the grapes with their juice and skins have been transported to the tank, so the maceration could start. The grapes we’ve been processing would have been left with their skins for 15 days.
There was no pressing involved, as we were processing the black grapes that will produce red wine.