Wine, a beloved beverage enjoyed for millennia, owes its enduring popularity to its diverse and complex composition. Derived from the fermentation of grape juice, wine encompasses an intricate balance of chemical compounds, including sugars, acids, tannins, and alcohols, that contribute to its distinctive taste, aroma, and mouthfeel. This article delves into the composition of wine, exploring the various elements that interact to create the sensory experience wine lovers cherish.
The Basic Components of Wine
Sugars
Grapes, the primary ingredient in wine, contain various sugars, including glucose and fructose. These sugars serve as the primary energy source for yeast during fermentation, transforming into alcohol, carbon dioxide, and other by-products [1]. The residual sugar left in the wine after fermentation determines its sweetness, with levels ranging from bone-dry to lusciously sweet.

Red wine pouring into wine glass. Bottle with dropstop. Dark background.
Acids
Acidity plays a crucial role in wine’s taste and structure, contributing to its freshness and vibrancy. The primary acids found in wine are tartaric, malic, and lactic acid [2]. Tartaric acid is the most abundant and stable acid in wine, helping to maintain its chemical balance. Malic acid contributes to the wine’s tartness, while lactic acid, produced during malolactic fermentation, imparts a smoother, creamier texture.
Alcohols
The most prominent alcohol in wine is ethanol, which results from the fermentation of grape sugars by yeast. Wine’s alcohol content varies, typically ranging from 8% to 15% by volume. The alcohol content contributes to the body, texture, and warming sensation of the wine, as well as influencing its flavor and aroma [3].
Tannins
Tannins are a group of naturally occurring compounds found in grape skins, seeds, and stems, as well as in oak barrels used for aging wine. They contribute to the astringency, bitterness, and mouth-drying sensation in wine, particularly red wine. Tannins play an essential role in the aging potential and overall structure of wine, with well-integrated tannins contributing to a wine’s balance and complexity [4].
Aromatic Compounds
Wine’s unique and enticing aromas arise from a complex array of volatile compounds that interact with one another and evolve during the wine’s production and aging processes. Some of the most important aromatic compounds include:
Esters
Esters, formed during fermentation, are responsible for many of the fruity aromas in wine. They result from the combination of acids and alcohols, with different esters responsible for different fruit scents, such as apple, pear, or strawberry [5].
Terpenes
Terpenes are a large group of aromatic compounds found in grape skins that contribute to the floral and citrus notes in wine. Some of the most well-known terpenes include linalool, geraniol, and limonene, which impart aromas of rose, geranium, and orange, respectively [6].
Pyrazines
Pyrazines are responsible for the herbaceous, green, and vegetal aromas found in some wines, particularly those made from underripe grapes or certain grape varieties such as Cabernet Sauvignon and Sauvignon Blanc. Pyrazines can evoke scents of green bell pepper, grass, or asparagus [7].
Thiols
Thiols are sulfur-containing compounds that contribute to the tropical, citrus, and sometimes savory aromas in wine. They are particularly prominent in Sauvignon Blanc, where they can impart aromas of passionfruit, grapefruit, and even blackcurrant [8].
Aging and Wine Composition
The passage of time also significantly impacts the composition of wine. As wine ages, both in the barrel and in the bottle, its components interact and evolve, leading to changes in flavor, aroma, and texture.
Oak Aging
During oak aging, wine can absorb various compounds from the oak barrels. These compounds, including tannins, lactones, and phenolic aldehydes, can impart flavors of vanilla, spice, smoke, or toast to the wine. Additionally, the slow introduction of oxygen through the barrel can lead to the oxidation of certain compounds, altering the wine’s aroma and color [9].
Bottle Aging
Once in the bottle, the wine continues to evolve through processes such as oxidation, polymerization, and esterification. Tannins can polymerize, becoming larger molecules that precipitate out of the wine, leading to a softer mouthfeel. Aromas can also evolve, with primary fruit aromas often giving way to more complex secondary and tertiary aromas, such as earth, spice, and nutty notes [10].
Conclusion
The composition of wine is a complex, dynamic symphony of chemical compounds that work together to create the sensory experience we enjoy in each glass. From the basic components of sugar, acids, alcohol, and tannins to the multitude of aromatic compounds and the transformative effects of aging, each aspect plays a vital role in shaping the wine’s character. So, the next time you savor a glass of wine, take a moment to appreciate the intricate dance of elements that contribute to its unique flavor and aroma.
References:
- Robinson, J. (2006). The Oxford Companion to Wine. Oxford University Press.
- Boulton, R., Singleton, V., Bisson, L., & Kunkee, R. (1996). Principles and Practices of Winemaking. Springer.
- Ribéreau-Gayon, P., Glories, Y., Maujean, A., & Dubourdieu, D. (2006). Handbook of Enology: The Chemistry of Wine Stabilization and Treatments. Wiley.
- Waterhouse, A. L., Sacks, G. L., & Jeffery, D. W. (2016). Understanding Wine Chemistry. Wiley.
- Jackson, R. S. (2014). Wine Science: Principles and Applications. Academic Press.
- Styger, G., Prior, B., & Bauer, F. F. (2011). Wine flavor and aroma. Journal of Industrial Microbiology & Biotechnology, 38(9), 1145-1159.
- Ryona, I., Pan, B. S., Intrigliolo, D. S., Lakso, A. N., & Sacks, G. L. (2008). Effects of cluster light exposure on 3-isobutyl-2-methoxypyrazine accumulation and degradation patterns in red wine grapes (Vitis vinifera L. Cv. Cabernet Franc). Journal of Agricultural and Food Chemistry, 56(24), 10838-10846.
- Tominaga, T., Furrer, A., Henry, R., & Dubourdieu, D. (1998). Identification of new volatile thiols in the aroma of Vitis vinifera L. var. Sauvignon blanc wines. Flavour and Fragrance Journal, 13(3), 159-162.
- Fernández de Simón, B., Cadahía, E., Jalocha, J. (2003). Volatile compounds in a Spanish red wine aged in barrels made of Spanish, French, and American oak wood. Journal of Agricultural and Food Chemistry, 51
Also read:
Wine is a drink that people all over the world enjoy. It has been around for a long time.. However, what people don’t know about wine is its many other uses. It can be utilized in cooking. It can also be a natural remedy for various ailments, such as headaches and colds. Wine can also be used to make vinegar for eating or cleaning purposes.
Why is Wine So Complex?
The winemaking process is complex because of the many variables that come into play from grape variety, temperature, yeast, bacteria, and more.
Besides these factors, several environmental factors can affect the process. The climate and soil conditions in which the grapes were grown can affect how much sugar and therefor alcohol will be in the wine.
The Role of Alcohol in the Human Diet
Alcohol is a substance that can be consumed for pleasure, for its psychoactive effects, or as a medication.[13] It is one of the most senior and most widely used drugs globally. Alcohol is not just an intoxicating substance but also has some nutritional value.
The alcohol content in food and beverages can provide calories, carbohydrates, proteins, and other nutrients. However, alcohol consumption has been linked to liver disease and cancer risk. See more articles here
This Day in Wine History
June 18, 1913: Robert Mondavi, a famous American winemaker, was born. He was not only a winemaker but a philanthropist who was given the “Order of Merit of the Italian Republic” award in 2002.
February 26, 1859: On this day, Romeo Bragato was born. He developed the wine industry of New Zealand and Australia, introducing new varieties of grapes to both countries. In particular, he created around 10,000 gallons of wine in Australia. [14]
September 17, 2008: One of the most famous winemakers in France, Didier Dagueneau died. He is known for his unique winemaking style. He was born in 1956 in the Loire Valley of France, where he started his career as a winemaker.
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References:
[1] Victor Armando Pereira de Freitas, Ana Fernandes, Joana Oliveira, Natércia Teixeira, Nuno Mateus
Vol. 51 No. 1 (2017): OENO One
Received : 7 November 2016; Accepted : 2 January 2017; Published : 28 March 2017
DOI: https://doi.org/10.20870/oeno-one.2017.51.1.1604
[2] En.m.wikipedia.org. 2022. Fermentation in winemaking – Wikipedia. [online] Available at: https://en.m.wikipedia.org/wiki/Fermentation_in_winemaking# [Accessed 20 May 2022].
[3] Gladstones, john. 1992. “Viticulture and Environment: A Study of the Effects of Environment on Grapegrowing and Wine Qualities, with Emphasis on Present and Future Areas for Growing Winegrapes in Australia.” john Gladstones 310.
[4] Jozef Ševcech, Ľubica Vicenová, Katarina Furdikova, Fedor Malik, Czech Journal of Food Sciences 33 (1), 91-96, 2015
[5] María-Pilar Sáenz-Navajas, Eva Campo, Purificación Fernández-Zurbano, Dominique Valentin, Vicente Ferreira, Food chemistry 121 (4), 1139-1149, 2010
[6] Saira Aijaz Khaderi, Clinics in liver disease 23 (1), 1-10, 2019
[7] En.m.wikipedia.org. 2022. Fermentation in winemaking – Wikipedia. [online] Available at: https://en.m.wikipedia.org/wiki/Fermentation_in_winemaking# [Accessed 20 May 2022].
[8] Triangle Wine Country Tours. 2022. The Components of Wine. [online] Available at: https://trianglewinecountry.com/wine-blog/the-components-of-wine/ [Accessed 20 May 2022].
[9] (E.A.Maury 2012) E.A.Maury. 2012. “your good health .” E.A.Maury 99
[10] Suresh Varma Penumathsa, Nilanjana Maulik
Canadian journal of physiology and pharmacology 87 (4), 275-286, 2009
[11] California Winery Advisor. 2022. The Most Popular Red Wine Grapes & White Wine Grapes | CWA. [online] Available at: https://californiawineryadvisor.com/red-wine-grapes-white-wine-grapes/ [Accessed 20 May 2022].
[12] Gladstones, John. Wine, terroir and climate change. Wakefield Press, 2011.
[13] Guiterrez, Winston. 2016. “Alcohol consumption.” Winston Guiterrez 211.
[14] En.m.wikipedia.org. 2022. Romeo Bragato – Wikipedia. [online] Available at: https://en.m.wikipedia.org/wiki/Romeo_Bragato [Accessed 20 May 2022].