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To improve the quality of fermented drinks, or more specifically, wine, some strains of yeast have been isolated, tested and studied, such as Saccharomyces and non-Saccharomyces. Some non-conventional yeasts present good fermentative capacities and are able to ferment in quite undesirable conditions, such as the case of must, or wines that have a high concentration of acetic acid. One of those yeasts is Lachancea thermotolerants (L. thermotolerans), which has been studied for its use in wine due to its ability to decrease pH through L-lactic acid production, giving the wines a pleasant acidity. This review focuses on the recent discovery of an interesting feature of L. thermotolerans—namely, its ability to decrease wines’ volatile acidity.

In recent years, in line with consumer preferences and due to the effects of global climate change, new trends have emerged in wine fermentation and wine technology. Consumers are looking for wines with less ethanol and fruitier aromas, but also with a good balance in terms of acidity and mouthfeel. Nonconventional yeasts contain a wide range of different genera of non-Saccharomyces. If in the past they were considered spoilage yeasts, now they are used to enhance the aroma profile of wine or to modulate wine composition. Recent publications highlight the role of non-Saccharomyces as selected strains for controlling fermentations mostly in cofermentation with Saccharomyces. In this article, I have reviewed the ability of some bacteria and non-Saccharomyces strains to modulate wine acidity.

The most known and traditional vinegar is the one that is made from wine. For its production, the grape must undergo alcohol fermentation and the posterior oxidation of ethanol to acetic acid. Yeasts and acetic acid bacteria (AAB) carry out the biochemical processes in sequence. The process of wine acetification can be achieved by slow traditional processes (the Orléans or French methods) or by a quick submerged industrial process. High-quality vinegar is usually produced by traditional methods using oak casks, once the wood allows the continuous aeration of the acetic bacteria culture. Sour–sweet vinegar presents a balance of both bitter/sour and sweet flavors. The sourness typically comes from acetic acid, while the sweetness can come from the type of fruit or the amount of sugar present at the end of vinegar production. In general, sour-sweet vinegar has a more complex and nuanced flavor profile compared to regular vinegar, which is often simply sour. One kind of vinegar produced by wine acetification where yeasts and bacteria co-exist and produce savory vinegar is traditional balsamic vinegar (TBV), from Italy. In Spain, fortified sherry wine has also been used for vinegar production. In Portugal, some wine companies have produced port wine vinegar since 2018. These three distinctive vinegar products have in common the sweetness that can be found, well balanced with the acetic acid sourness. In this review, we analyze the sour-sweat wine vinegar process, bearing in mind the possible interactions between yeasts and AAB that occur during vinegar production and considering the symbiotic or competitive features of a diverse microbiota.

Modern industrial winemaking is based on the use of specific starters of wine strains. Commercial wine strains present several advantages over natural isolates, and it is their use that guarantees the stability and reproducibility of industrial winemaking technologies. For the highly competitive wine market with new demands for improved wine quality and wine safety, it has become increasingly critical to develop new yeast strains. In the last decades, new possibilities arose for creating upgraded wine yeasts in the laboratory, resulting in the development of strains with better fermentation abilities, able to improve the sensory quality of wines and produce wines targeted to specific consumers, considering their health and nutrition requirements. However, only two genetically modified (GM) wine yeast strains are officially registered and approved for commercial use. Compared with traditional genetic engineering methods, CRISPR/Cas9 is described as efficient, versatile, cheap, easy-to-use, and able to target multiple sites. This genetic engineering technique has been applied to Saccharomyces cerevisiae since 2013. In this review, we aimed to overview the use of CRISPR/Cas9 editing technique in wine yeasts to combine develop phenotypes able to increase flavor compounds in wine without the development of off-flavors and aiding in the creation of “safer wines.”

Non-Saccharomyces are important during wine fermentation once they influence wine composition. In the early stages of wine fermentation, and together with indigenous or commercial strains of Saccharomyces cerevisiae, non-Saccharomyces are able to transform grape-must sugars into ethanol, CO2, and other important secondary metabolites. A better understanding of yeast biochemistry will allow the selection of yeast strains that have defined specific influences on fermentation efficiency, wine quality, and the production of human health-promoting compounds. Yeast metabolism produces compounds derived from tryptophan, melatonin, and serotonin, which are found in fermented beverages, such as wine and beer. Melatonin is a neurohormone secreted from the pineal gland and has a wide-ranging regulatory and neuroprotective role, while serotonin, as well as being a precursor of melatonin synthesis, is also a neurotransmitter. This review summarizes the importance of some conventional and nonconventional yeast strains’ alcoholic fermentations, especially in the production of metabolites that promote human health and thus, attract consumers attention towards fermented beverages. A brief reference is also made on fermented beverages containing probiotics, namely kombucha, also known as kombucha tea, and its interesting microorganism’s symbiotic relationships named SCOBY.

Wine sensory experience includes flavor, aroma, color, and (for some) even acoustic traits, which impact consumer acceptance. The quality of the wine can be negatively impacted by the presence of off-flavors and aromas, or dubious colors, or sediments present in the bottle or glass, after pouring (coloring matter that precipitates or calcium bitartrate crystals). Flavor profiles of wines are the result of a vast number of variations in vineyard and winery production, including grape selection, winemaker’s knowledge and technique, and tools used to produce wines with a specific flavor. Wine color, besides being provided by the grape varieties, can also be manipulated during the winemaking. One of the most important “tools” for modulating flavor and color in wines is the choice of the yeasts. During alcoholic fermentation, the wine yeasts extract and metabolize compounds from the grape must by modifying grape-derived molecules, producing flavor-active compounds, and promoting the formation of stable pigments by the production and release of fermentative metabolites that affect the formation of vitisin A and B type pyranoanthocyanins. This review covers the role of Saccharomyces and non-Saccharomyces yeasts, as well as lactic acid bacteria, on the perceived flavor and color of wines and the choice that winemakers can make by choosing to perform co-inoculation or sequential inoculation, a choice that will help them to achieve the best performance in enhancing these wine sensory qualities, avoiding spoilage and the production of defective flavor or color compounds.

A relevant trend in winemaking is to reduce the use of chemical compounds in both the vineyard and winery. In organic productions, synthetic chemical fertilizers, pesticides, and genetically modified organisms must be avoided, aiming to achieve the production of a “safer wine”. Safety represents a big threat all over the world, being one of the most important goals to be achieved in both Western society and developing countries. An occurrence in wine safety results in the recovery of a broad variety of harmful compounds for human health such as amines, carbamate, and mycotoxins. The perceived increase in sensory complexity and superiority of successful uninoculated wine fermentations, as well as a thrust from consumers looking for a more “natural” or “organic” wine, produced with fewer additives, and perceived health attributes has led to more investigations into the use of non-Saccharomyces yeasts in winemaking, namely in organic wines. However, the use of copper and sulfur-based molecules as an alternative to chemical pesticides, in organic vineyards, seems to affect the composition of grape microbiota; high copper residues can be present in grape must and wine. This review aims to provide an overview of organic wine safety, when using indigenous and/or non-Saccharomyces yeasts to perform fermentation, with a special focus on some metabolites of microbial origin, namely, ochratoxin A (OTA) and other mycotoxins, biogenic amines (BAs), and ethyl carbamate (EC). These health hazards present an increased awareness of the effects on health and well-being by wine consumers, who also enjoy wines where terroir is perceived and is a characteristic of a given geographical area. In this regard, vineyard yeast biota, namely non-Saccharomyces wine-yeasts, can strongly contribute to the uniqueness of the wines derived from each specific region.

Tannins, a diverse class of polyphenolic compounds, are widely present in a variety of plant-based foods and beverages, where they contribute significantly to flavor, astringency, and numerous health benefits. Known for their antioxidant, anti-inflammatory, and cardioprotective properties, tannins are associated with a reduced risk of chronic diseases such as cardiovascular disease, cancer, and diabetes. Their bioavailability and metabolism are influenced by factors such as polymerization, solubility, and interactions with the gut microbiota. Tannin-rich beverages, including tea, wine, fruit juices, and cider, offer a range of health-promoting effects, including antioxidant, cardioprotective, and antimicrobial activities. In addition, tannins contribute significantly to the sensory and nutritional characteristics of fruits, nuts, and vegetables, influencing flavor, color, and nutrient absorption. The levels and efficacy of tannins are subject to variation due to factors such as ripeness and food processing methods, which can increase their impact on food quality and health. This review provides a comprehensive examination of the bioactive roles of tannins, their nutritional implications, and their sensory effects, highlighting their importance in both dietary applications and overall well-being.

Grape musts sometimes reveal excess acidity. An excessive amount of organic acids negatively affect wine yeasts and yeast fermentation, and the obtained wines are characterized by an inappropriate balance between sweetness, acidity or sourness, and flavor/aroma components. An appropriate acidity, pleasant to the palate is more difficult to achieve in wines that have high acidity due to an excess of malic acid, because the Saccharomyces species in general, cannot effectively degrade malic acid during alcoholic fermentation. One approach to solving this problem is biological deacidification by lactic acid bacteria or non-Saccharomyces yeasts, like Schizosaccharomyces pombe that show the ability to degrade L-malic acid. Excessive volatile acidity in wine is also a problem in the wine industry. The use of free or immobilized Saccharomyces cells has been studied to solve both these problems since these yeasts are wine yeasts that show a good balance between taste/flavor and aromatic compounds during alcoholic fermentation. The aim of this review is to give some insights into the use of Saccharomyces cerevisiae strains to perform biological demalication (malic acid degradation) and deacetification (reduction of volatile acidity) of wine in an attempt to better understand their biochemistry and enological features.

Humans have used their senses to evaluate food for several thousands of years. Since so many phytotoxins and bacterial metabolites are bitter and sour, humanity probably used sensory evaluation since before Homo sapiens were human. The necessity for herbal teas driven by the functional health benefits associated has far beaten global supply. [...]this is an important study, not only in terms of academic knowledge but also for industrial purposes. The results demonstrated that rooibos and Honeybush tea had an overall sweet-caramel, honey-sweet, perfume floral, and woody aroma while bush tea and special tea depicted green-cut grass, dry green herbal, and astringent/dry mouthfeel. [...]compounds identified in this study can be valuable markers for discriminative herbal tea sensory characteristics. [...]a review article was written by Vilela et al.