In two years, a perfect control of the oxygen parameter has been put in place on all their cuvées. At different stages of the winemaking and especially at bottling, oxygen analysis has become an integral part of the company's quality controls. The gain: a decrease of sulfites used while significantly improving the shef-life of their rosés, particularly sensitive to oxidation, and whose aromatic finess is now better preserved.
The starting point: the oxygen audit
It all started in 2015. "We noticed that some of the bulk rosés that were taken from our members showed a faster aromatic evolution and were not as good after bottling. We then decided to perform an oxygen audit of the process from collecting wines from our members' cellar to the reception to our bottling facilities, with Wine Quality Solutions, the Vinventions’ enological services brand", explains Stéphan Reinig, quality manager at Estandon Vignerons. Bulk wine loading and downloading, wine transfer and bottling have been inspected for oxygen pick-up. The results obtained make it possible to identify the critical oxygen pick-up steps, and to put in place corrective actions. A first level is reached: the company understands what significant improvements could be implemented thanks to oxygen controls throughout their winemaking process. Estandon acquired the NomaSense O2 P300 oxygen analyzer to perform the oxygen controls themselves and appointed a dedicated person with the mission of "wine oxygen reduction".
More than 250 oxygen measurements performed
At the end of 2016, regular oxygen measurements throughout the production process are put in place. Each transfer is then monitored, each pump tested, and the crucial bottling step monitored meticulously, for their 3 bottling lines. "We have carried out nearly 250 measurements and it is the minimum to have a comprehensive view of our practices. You can’t see oxygen, you can’t smell it, and there is only one way guide us every day through the improvements to put in place it is to measure it. Thanks to these measurements, we have identified, for example, the failure of one of the cellar pumps, which was sent for maintenance, as well as the lack of performance of the filling heads of one of the bottling lines, which was then replaced in 2017", says Reinig. In 2018, Estandon starts a new improvement project: reducing oxygen pickups when bottling with screwcaps. "The ullage in the case of screw-capped bottles is about 50 mm, which represents a large reservoir of gaseous oxygen intake. Despite an inerting system installed on the line, our oxygen controls revealed the need to find a more efficient inerting system. We then decided to go for the NomaLine HS 6000, the headspace inerting system developed by Wine Quality Solutions for screwcaps bottling machine", continues the quality manager.
2 ppm oxygen lower in headspace, 5 ppm of SO2 preserved in bottles
At the time of the NomaLine HS6000 installation, headspace oxygen measurements performed in comparison with the old system, have shown that NomaLine allows reducing the headspace oxygen pickup at 1.5 ppm on a line at 9000 bottles per hour, i.e. 2 ppm less than the previous inerting system. "It has been possible to decrease headspace oxygen by at least two times, but also to reduce the variability of these oxygen intakes compared to the previous system. Reducing oxygen by 2 ppm, it is a "gain" of 5 ppm of free SO2 in our wines. We bottle more and more organic wines and to meet the specifications for this type of wines, these 5 ppm make the difference. In addition, capping with screwcaps is growing. We are therefore very satisfied with this system, which allowed us to considerably improve our bottling performance with screwcaps" concludes Stéphan Reinig. And oxygen sensing remains essential to carry out all these improvements, reminds Reinig