ASSISTANT PROFESSOR – Ms. ISHANJALI

DEPARTMENT OF CHEMISTRY

UTTARANCHAL (P.G) COLLEGE OF BIO MEDICAL SCIENCES & HOSPITAL,

NEAR I.S.B.T, SEWLA KHURD, GMS – TRANSPORT NAGAR ROAD, DEHRADUN, UTTARAKHAND, INDIA

Wines offer us a variety of aroma and flavors, some flying confidently from the bottle with the pop of the cork, others developing slowly and delicately as the wine breathes, or when it hits our palette. Wine bouquets are described variously as buttery, floralsmoky, or chocolatey. They may be bestowed with labels claiming flavor notes as diverse as berries, plums, pepper, spice, nuts, cream, vanilla, oak, or grass.Every glass of wine has unique nuances of taste and smell that come from complex chemistry. Any bottle is 98% water and ethanol, no matter its provenance; but it’s the remaining 2% that makes the difference. The grape varietal itself is important, and there are more than 10,000 varieties used in wine making, all producing different tastes and smells, and each host to different types of yeast that play their part in fermentation. But flavor can also be impacted by external factors, such as processing and storage. For example, the type of wood used to make the barrels that the wine is aged in can add extra tannins to the mix, bringing bitterness and astringency. Climate too can have an effect, since fruit sugars develop more slowly at colder temperatures, meaning that vineyards in cooler climates make subtle, lower alcohol wines, whereas hotter locations results in stronger, more robust products. Terroir is an additional concept to take into account when considering the diverse and complex chemistry of wine.

Terroir describes the character brought to the wine by the unique physical and biological growing environment that influences distinctive characteristics in the grape – from the organic and geological makeup of the soil to the particular layout of the vines and the degree of sun exposure and irrigation. There are over 60 trace elements found in wine that come from the soil – such as sodium and potassium cations that may give a salty taste. Terroir is a uniquely individual signature that would be impossible to copy, and is responsible for sensory diversity even within wines of the same variety.