Fumaric acid (FH2) is an additive allowed by the Codex Alimentarius and the International Organization of Vine and Wine (OIV) that can be used for wine acidification but also to inhibit malolactic fermentation (MLF). FH2 has a positive effect in the reduction in SO2 doses by controlling LAB and other bacteria and by preserving molecular SO2 due to pH effect. This article reports the use of FH2 at 600 mg/L in wines produced with 3 varieties of Vitis vinifera L. grapes (Tempranillo, Garnacha and Viura) made in vintages 2018, 2020 and 2021. Wines treated with 600 mg/L of FH2 were more stable in the long term and showed lower pH by the preservation of malic acid due to both the absence of MLF (which reduced the pH in 0.1–0.2 units compared with controls) and the effect of FH2 acidification (what produced and additional reduction of 0.05–0.1 pH units). The wines treated with FH2 also remained with very low volatile acidity contents close to 0.2 mg/L or lower. These results corroborate that FH2 can be used to successfully control malolactic fermentation in all still wine types (red, white, and rose) from either of the studied varieties.

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Pulsed light is an emerging technology used to limit the proliferation of microorganisms in food matrices. The treatment consists on the emission of ultra-short high intensity white light pulses. The light is composed by ultraviolet, visible and near infrared spectra. Its use in enology allows the winemaker to carry on ternary (simultaneous) and sequential fermentations. The PL working conditions were determined through this investigation at the same time that the implantation feasibility of yeast and bacteria for the acidification of red wine was assed. The experimental set up evaluated different doses (number of pulses and energy density) on destemmed grapes. The grapes were placed inside a laboratory-scale cabinet inside a tray and the grapes were mixed randomly three times within the treatment. The microorganisms (both native and inoculated) were followed up with selective and differential growing media. The yeast population decreased 1.2 log10 UFC/mL, although the reduction is less sensitive when the initial population is already low (e.g. 1 × 102 UFC/mL). The use of PL favored the accumulation of lactic acid, produced by either yeast or bacteria, in treated musts. The concentration of lactic acid was higher when using L. thermotolerans against the use of O. oenni in coinoculation or sequential MLF.