Most oxidation reactions in wine require iron as a catalyst. The iron content of wine has decreased greatly in recent decades due to the use of low or no release cellar materials; however, in some cases it is still necessary to adopt winemaking practices to remove excess iron from wine, prevent its oxidation, and be able to reduce the addition of sulfur dioxide and other antioxidants.

Brettanomyces bruxellensis is found in various ecological niches, but particularly in fermentative processes: beer, kombucha, cider and wine. In the oenological sector, this yeast is undesirable, as it can produce ethyl phenols, thus altering wine quality. These compounds are characterized by stable or horse-sweat aromas, unpleasant for consumers.

Eugenol has been identified as a quality marker in armagnac white spirits. In particular, those produced from the Baco blanc variety, the only hybrid variety authorised in a French PDO, bred since 1898 from noah (vitis labrusca x v.riparia) and folle blanche (v. Vinifera). The varietal compound of Baco blanc, eugenol has many original properties.

The use of medium chain fatty acids for arresting the fermentation and producing sweet wines was investigated at industrial level. Doses of 10 mg/l of octanoic or decanoic acid and a combination of 5+5 mg/l octanoic and decanoic acid were used to produce sweet wines of tamaioasa romanească variety in volumes of 3000 l.

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.

In recent years, the consumption of fine wines in Brazil has increased significantly, a phenomenon that is also reflected in the expansion of production to new regions. In the brazilian southeast for example, the so-called “winter wines” are being produced, through management in two cycles, one of formation and one of production, with two prunings and one harvest per year, a technique known as double pruning, with vineyards established at altitudes close to or above 1,000 m above sea level.

Life cycle assessment (LCA) is an effective and comprehensive method for evaluating the environmental impact of a product, considering its entire life cycle. In the context of wine production, although the use of lca is gaining ground in viticulture, its application is still limited to the fine assessment of winemaking processes.

Wine aging with oak chips is nowadays a common alternative to barrel aging, aiming to improve wine quality through the fast extraction of wood derived compounds. From the pool of wood phenols, ellagitannins have been reported to have the most significant impact on the wine’s organoleptic profile. Their final concentration in wines is influenced by several factors, with toasting level considered as one of the most important.

These days, consumers are interested in food products linked to the environment and the concept of naturalness. They prefer “free” products, such as those with no pesticide residues or no added sulfur dioxide (so2) in wines. In fact, so2 is the most widely used preservative in winemaking, as it has multiple properties at low cost: it is antioxidant, antioxidasic and antimicrobial.

Acid aspergillopepsins-i (ap-i) have been suggested for use in winemaking due to their ability to degrade proteins, which reduces haze formation and the necessity for bentonite to achieve protein stability. These endopeptidases cleave non-terminal amino acid bonds of proteins, resulting in their degradation.

Pinking describes the appearance of a salmon-red blush in white bottled wines produced exclusively from white grape varieties. It is understood as an undesirable chromatic phenomenon by both wine consumers and the industry. Nowadays, there are no treatments to fully reverse pinking once it occurs. Partial reversion has been shown after exposure of pinked wine to ultraviolet (UV) light.