Pellenc has been kind enough to use Vrede en Lust as one of its South African test wineries for its exciting new Selectiv Process Winery sorter. When grapes are harvested they come with MOG (matters other than grape) and berries are unsuitable for quality wine production.
The term MOG covers a range of things including snails, snakes, worms, insects, cameleons or even rodents! It may also include stems (if the winemaker does not want stems in the must) and leaves. Unsuitable berries typically include the likes of shot berries (little hard green berries that did not develop properly), grapes that have become raisins or grapes that have rot due to bird damage or actual rot due to the likes of rain at the wrong time.
The goal with sorting the bunches and/or berries is to reduce the MOG reaching the must and also reduce the amount of undesirable berries from impacting quality. Manual berry level sorting is quite a labour intensive job and adds significantly to the cost of production, while also being a fairly slow process which may result in other unintended problems like oxidation.
A few companies (mainly French) have been working hard to perfect the so-called automatic grape sorting machines. These machines will eliminate the human intervention and thus lower the cost of sorting while speeding up the process, significantly to reduce the risk of oxidation.
Susan and her team have the new Pellenc Selectiv Process machine here for the first week of March to test it and give Pellenc feedback. It is only day one of operation, so it is early to tell and the final proof will come in the finished products.
Susan is very positive about the initial results thus far. The destemming process is very effective and virtually no few stems reach the must. The shiraz harvested today went through well, with raisin berries eliminated with the stems and shot berries (not really a problem with our shiraz).
A lot of pip (grape seeds) were eliminated too. As the pips contain the harshest of the tannins, it will be very interesting to see how the wine develops. The grapes are destemmed by beating rods as used in grape harvesting machines. The bulk of the raisins and shot berries remained on the stems, the ones that got through were caught by the sorting rollers.
We also brought in a load of Sauvignon Blanc from a neighbour in Elgin’s vineyard. The machine handled the Sauv Blanc well and the juice is currently in tank settling. We will need to experiment some with the setting of the sorter, but it caught the shot berries, MOG and stems very well.
I took a few photo’s of the process running. As the photo’s show, the machine seems be doing its work fast and well. The sorter can apparently process up to 8 tons per hour, which is more than enough for our winery. We have budgeted for an automatic sorting machine as part of our current winery expansion program, so if the tests go well, you may well see the Selectiv Process machine find a permanent home below the receiving bin!