National Drink Wine Day

Photo by Mick Stephenson

Photo by Mick Stephenson

National Drink Wine Day is celebration on February 18th of each year.

Wine is an alcoholic beverage made from fermented grapes or other fruits. The natural chemical balance of grapes lets them ferment without the addition of sugars, acids, enzymes, water, or other nutrients. Yeast consumes the sugars in the grapes and converts them into alcohol and carbon dioxide. Different varieties of grapes and strains of yeasts produce different styles of wine. The well-known variations result from the very complex interactions between the biochemical development of the fruit, reactions involved in fermentation, terroir and subsequent appellation, along with human intervention in the overall process. The final product may contain tens of thousands of chemical compounds in amounts varying from a few percent to a few parts per billion.

Wines made from produce besides grapes are usually named after the product from which they are produced (for example, rice wine, pomegranate wine, apple wine and elderberry wine) and are generically called fruit wine. The term “wine” can also refer to starch-fermented or fortified beverages having higher alcohol content, such as barley wine, huangjiu, or sake.

Wine tasting is the sensory examination and evaluation of wine. Wines contain many chemical compounds similar or identical to those in fruits, vegetables, and spices. The sweetness of wine is determined by the amount of residual sugar in the wine after fermentation, relative to the acidity present in the wine. Dry wine, for example, has only a small amount of residual sugar.

Some wine labels suggest opening the bottle and letting the wine “breathe” for a couple of hours before serving, while others recommend drinking it immediately. Decanting (the act of pouring a wine into a special container just for breathing) is a controversial subject among wine enthusiasts. In addition to aeration, decanting with a filter allows the removal of bitter sediments that may have formed in the wine. Sediment is more common in older bottles, but aeration may benefit younger wines.

During aeration, a younger wine’s exposure to air often “relaxes” the drink, making it smoother and better integrated in aroma, texture, and flavor. Older wines generally “fade” (lose their character and flavor intensity) with extended aeration. Despite these general rules, breathing does not necessarily benefit all wines. Wine may be tasted as soon as the bottle is opened to determine how long it should be aerated, if at all.

When tasting wine, individual flavors may also be detected, due to the complex mix of organic molecules (e.g. esters and terpenes) that grape juice and wine can contain. Experienced tasters can distinguish between flavors characteristic of a specific grape and flavors that result from other factors in winemaking. Typical intentional flavor elements in wine—chocolate, vanilla, or coffee—are those imparted by aging in oak casks rather than the grape itself