Stability of 3-mercaptohexanol during white wine storage in relationship to must pre-fermentative fining

The use of selected cultures of the species Lactiplantibacillus plantarum in Oenology has grown in prominence in recent years. While initial applications of this species centred very much around malolactic fermentation (MLF), there is strong evidence to show that certain strains can be harnessed for their bio-protective effects. Unwanted spontaneous MLF during alcoholic fermentation (AF), driven by rogue Oenococcus oeni, is a winemaking deviation that is very difficult to manage when it occurs. This work set out to determine the efficacy of one particular strain of Lactiplantibacillus plantarum(Viniflora® NoVA™ Protect), against this problem in Cabernet Sauvignon must. The work was carried out at commercial scale and in a winery environment and compared the bio-protective culture with the more traditional approach of reducing must pH by the addition of tartaric acid. The combination of both was also investigated. The concentration of both Oenococcus oeni and Lactiplantibacillus plantarum was determined using qPCR. The adventitious Oenococcus oeni showed the most growth during AF in the control wine, whereas in the wines treated with Lactiplantibacillus plantarum a bacteriostatic effect against this species was observed. This effect was comparable to the wines treated with tartaric acid. This has particular commercial relevance for controlling the flora in musts with high pH, or when the addition of tartaric acid is either not permitted or is prohibitive for other reasons.

Climate change is driving global temperatures up together with a reduction of rainfall, posing a risk to grape yields, wine quality, and threatening the historical viticulture areas of Europe.

The Champagne vineyard extends over 35,300 ha under the Appellation d’Origine Contrôlée, of which 30,000 are in production. It mainly covers 3 departments: in order of importance, Marne (68% of the appellation area), Aube (22%) and Aisne (10%), and more anecdotally Haute Marne and Seine and Mame. It is a young vineyard (for more than half of the surface, the winegrowers have the experience of only one generation of vines), and fragmented (more than half of the exploitations extend over less than 1 ha; the average size of a cadastral parcel is 12 ares).

Extension of the growing season, compression of the annual growth cycle and higher frequency and severity of weather extreme events are consistent features of global warming. While mitigation of factors causing global warming is necessary in the medium-long term, wine growers need “ready to go” adaptation practices to counteract negative effects bound to climate change. This must be done in a sustainably way, meaning that remunerative yield, desired grape quality, low production cost and environment friendly solutions must be effectively merged. In this work, we will review contribution given over the last two decades prioritizing issues related to scion and rootstock choice, changes in vineyard floor management, new perception related to the use of irrigation in vineyards, adaptation practices aimed at decompress maturity, solutions to counteract or minimize damages due to late frost and sunburn and, lastly, some hints on how precision viticulture can help with all of this.

Yeast protein extracts (ypes) have flocculating properties, allowing clarification of musts and wines. They are already authorized by oiv for fining purposes with a maximum dosage limit of 60 g/hl for red wines, and 30 g/hl for musts, white and rosè wines. The extraction of ypes from the cytoplasm of yeasts (saccharomyces spp) cells is defined by the resolution oiv oeno 452-2012, that indicate also some specification of the final product.