## 1 Introduction  
Most red wines, but also some white wines and basic sparkling wines, undergo malcolactic fermentation (MLF) to improve wine organoleptic properties and provide further improvements. Traditionally, _Oenooccus oem_ has been chosen to carry out MLF [1; 2; 3], thanks to its ability to tolerate the unfavourable environment of wine after the end of alcoholic fermentation [4]. However, exploration of relevant eoncological characteristics of _Lactobacillus plantarum_, such as tolerance to harsh wine conditions similar to _Oenooccus oem_, and a more diverse array of enzymes for wine aroma and colour changes [5], contribute to the arrival of _L. plantarum_ as the new generation of wine MLF starter cultures [6; 7; 8].  
Several works on changes in the chemical and organoleptic properties of wine are based on the comparison of _O. oenti_ and _L. plantarum_ for their metabolic potentials [9; 10; 11; 12], the timing of inoculation [10; 13; 14] or yeast interaction, with each of the two bacterial strains [15; 16; 17]. All previous studies have focused on the use of a single MLF culture (either _O. oenti_ or _L. plantarum_) for an overall reduction in fermentation time or changes in the volatile and sensory properties of wine [18]. Previous studies have shown that different strains with different metabolic activities could alter the wine characteristics, depending on the fermentation parameters [19; 20].  
Limited studies have focused on a blend of both _L plantarum_ and _O. oenti_ on wine organoleptic properties and fermentation dynamics [7; 9]. The studies observed a distinct profile of volatile compounds mainly for anthocyanin and other phenols at various inoculation timings [13]. The differences were considered to be the result of the metabolism of yeast and bacteria in the different stages of wine fermentation [15].  
The overall aim of this research is to verify whether the early inoculation of homolactic acid bacteria for hexoses (_L. plantarum_), carried out after 24 h, compared with that of the saccharomyces operating alcoholic fermentation, could be advantageous with respect to a traditional innoculation with a different heterolactic bacterial strain for hexoses (_O. oenti_) operated at the end of alcoholic fermentation. In particular, the moment at which the starter cultures of lactic acid bacteria are inoculated is an important factor that influences not only the success of malolactic fermentation, in terms of depletion of metabolisable compounds (e.g., malic acid, hexoses, citric acid), but also the management of subsequent cellar operations. In addition, the methods of inoculation affect the time interval during which the must/wine is exposed to microbial and oxidative alterations. The grape variety chosen was Sangiovese, the protagonist of Tuscan oenology and the main component of the seven Tuscan DOCGs: Brunello di Montalcino, Carmignano, Chianti, Chianti Classico, Morellino di Scansano, Montecucco, and Nobile di Montepulciano. Currently, the \"Sangiovese\" vine is the most widespread vine in Italy, with about 10% of the total vineyard area [21]. In Tuscany, it is the most widespread vine, with 67.4% of the regional wine-growing area [22].  
The evaluation focused on different aspects such as the management of winery operations, the quality and longevity of the product, carried out in all phases of winemaking, analysed both from a chemical and sensory point of view.