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Chemistry of Red Wine - What gives red wine their taste?

Tannin is a water soluble organic substance present in wines and tea as well as other drinks like beer, grape juice, apple juice and apple cider to give them a taste known as astringency (Wine Folly, 2020). It is supposedly found the most in red wines in comparison to other beverages but there is some presence in white wine from being stored in wooden barrels at really cold temperatures. The word “tannin” originates from the latin word “tanner” and refers to the use of tree bark. Some examples of wine tannins include grape seeds, grape skins, tannin powder and oak.

Tannins are used in wines to balance out the taste in wine when complemented with food (Wine Society, 2014). They are also used to help in the aging process of wine, with the wines that have the highest tannin concentrations aging the best for long periods of time (Compound Chem, 2017). Tannins play an important role ‘as a raw material for sustainable green industries’ (IntechOpen, 2019) thus being used prominently in sustainability related industries like beverages. Tannins can also be applied as potential medicinal agents and antioxidants due to them displaying important properties like antiseptics, anticarcinogenic and anti-inflammatory properties which is what makes them suitable for pharmaceuticals. A major ongoing issue is that synthetic compounds with a lot of harmful chemicals are utilised in human health and food industries, creating adverse effects on the body and to substitute these harmful chemicals tannins can be used as an alternative (IntechOpen, 2019).

What gives the colour to the wine is the fact that there is the presence of a substance known as anthocyanins, a part of a group of substances known as flavonoids, powerful antioxidant agents. When red wine is being made, the grapes are crushed and placed into vats, with the extra parts such as the stems and pulp forming residue, giving the wine its musty smell. When the alcohol goes through the fermenting process, the colour of the wine depends on the time the juice from the skins and the extra parts of the grapes is in contact with the must. The longer the time, the more dark the wine. On the other hand, white wine is made from crushing the grapes at a fast pace to allow the juice created to ferment.

Finally, red wines have another presence of a chemical called flavonols. Flavonols have an isomer called flavon-3-ols which differ very slightly as flavon-3-ols have some sensory impacts as well. The main use of flavonols is to give red wine its bitter taste. The most common type of flavon-3-ols are called Catechin and Epicatechin and they can be found in other antioxidant beverages like tea and they come from the seeds of the grapes, displaying its benefits (Compound Chem, 2017).

Although alcohol is known for not being a very healthy beverage, red wine in particular does have some health benefits when it comes to drinking. This is due to a compound known as resveratrol. Resveratrol “has anti-inflammatory effects” due to the free radicals present that can react with our bodies, helping reduce inflammation. However not all of these health benefits have been studied in excruciating detail but maybe before opening a bottle of red wine, learning these benefits and the composition may surprise you (Compound Chem, 2017).

Works Cited

Clegg, Brian. "Tannins." Chemistry World, 30 Apr. 2014.

"Discover The 5 Basic Wine Characteristics." Wine Folly, 18 Apr. 2020,

P. Singh, Akhlash, and Sunil Kumar. "Applications of Tannins in Industry." Tannins - Structural Properties, Biological Properties and Current Knowledge, 27 Sept. 2019.

"The Key Chemicals in Red Wine – Colour, Flavour, and Potential Health Benefits." Compound Interest, 18 Feb. 2017,

Lee, Jessica A. "The Life and Times of a Tannin Molecule." Welcome | Stanford Wine Society, 2 Sept. 2014,

Krebiehl, Anne M. "What Are Tannins, Really?" Wine Enthusiast, 4 Dec. 2018,

Watrelot, Aude A., and Erin L. Norton. "Chemistry and Reactivity of Tannins in Vitis spp.: A Review." Molecules, vol. 25, no. 9, 2020, p. 2110.

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