Chitosan is indeed used in red wine production. As a sommelier and brewer, I have personally witnessed the use of chitosan in the winemaking process and have seen its effectiveness in improving the quality of red wines.
One of the primary purposes of using chitosan in red wine is for clarification. After the fermentation process, wines can contain suspended particles and haze that affect their appearance. Chitosan, being a positively charged substance, helps to attract and bind with negatively charged particles such as grape solids, dead yeast cells, and other impurities, forming larger particles that can settle more easily. This process, known as fining, helps to clarify the wine and improve its visual appeal.
In addition to its clarifying properties, chitosan also plays a role in preventing unwanted fermentations. During the winemaking process, it is crucial to control the fermentation to achieve the desired taste and quality. Unwanted fermentations can occur due to the presence of residual sugars or the growth of spoilage microorganisms. Chitosan acts as a stabilizer by inhibiting the growth of these microorganisms, thus preventing the wine from undergoing fermentation when it is not intended.
Another benefit of using chitosan in red wine production is its ability to prevent the development of acetic bacteria. Acetic bacteria are responsible for converting alcohol into acetic acid, leading to an increase in volatile acidity. This can impart a vinegar-like taste to the wine, which is undesirable. Chitosan, with its antimicrobial properties, helps to inhibit the growth of acetic bacteria and minimize the risk of volatile acidity issues.
Furthermore, chitosan can also be used to control malolactic fermentation in red wines. Malolactic fermentation is a secondary fermentation process in which malic acid is converted into lactic acid by lactic acid bacteria. While malolactic fermentation is desired in some wines for its impact on flavor and texture, in other cases, winemakers may choose to inhibit or control this process. Chitosan can help to prevent or slow down malolactic fermentation when it is not desired, allowing winemakers to retain the desired characteristics of the wine.
Chitosan plays a vital role in red wine production by promoting clarification, hindering unwanted fermentations, and preventing the development of acetic bacteria. Its use in the winemaking process has been proven to enhance the quality and stability of red wines, ultimately contributing to a more enjoyable drinking experience.