Great wine begins with the grapes themselves. The process of growing grapes is called viticulture, and it’s a much more sophisticated process than you might imagine. Grape vines are greatly impacted by the climate and region in which their grown. Factors such as amount of sunlight, rain, or wind, temperature, soil composition and quality, and even the topography of the land can have a massive influence on the character and quality of the grapes grown.
In fact, these factors are so important that there is a term for them in wine culture. “Terroir” refers to the collective characteristics of a specific piece of land, which are ultimately reflected in the wine. Terroir literally means a “sense of place”. Terroir varies significantly across wine regions, but can even differ greatly within a region or from individual vineyard to vineyard.
And even in an ideal location, you can’t just plant any old grapes. Certain grape varietals grow best in particular environments and so the wine grower must carefully match the individual grape vines to their surroundings. It’s an art that takes many years of education and trial and error to perfect.
Let’s move on to the grapes themselves.
Grapes are approximately 75% pulp, 20% skin, and 5% seeds.
The pulp is the soft, juicy center of the grape. It consists of water and sugar, and is the part of the grape that eventually becomes the wine.
Sugar is really the critical component in winemaking, because it’s the sugar that becomes the alcohol during the fermentation process. Grapes with a higher sugar content at harvest, can produce wines with a higher alcohol content.
While we’re discussing sugar, let’s take a moment to understand how sugar affects the sweetness of a wine. You have probably heard wines being described as either sweet or dry. These terms are really describing the amount of sugar remaining in the final wine. If all of the sugar in the grape is converted to alcohol during fermentation, the wine is considered dry. If some of the sugar remains behind after fermentation, than the wine has ‘residual sugar’, and is considered sweet.
Wine drinkers often confused sweetness with fruitiness. But fruitiness is actually something entirely different. It is simply the propensity of the wine to have fruit-like flavors and aromas. This has nothing to do with the sugar content. A wine can be both sweet and fruity, or both dry and fruity. But it can never be both sweet and dry.
Now let’s move on to the grape skins. Skins also play a critical role in winemaking, particularly in the production of red wine. The skins are largely responsible for imparting the aroma and flavor of the wine, as well as the color and tannins. All of these elements can be further influenced by the winemaker by varying the length of time that the skins are left in contact with the wine during the production process.
Let’s take a closer look at tannins. You’ve probably heard the term but most people have a pretty hard time describing what tannins actually are. From a technical standpoint, tannins are naturally occurring molecules that are found in plant leaves, seeds, stems, and fruit skins.
In the context of wine, tannin is a structural element that makes wine taste dry and astringent. It is sometimes described as the ‘pucker power’ of the wine, since a very tannic wine can make your lips pucker.
Achieving the right level of tannin is important to a wine maker. Tannins add structure and interest too a wine. But a wine with too little tannin can taste dull and flat, while a wine with too much tannin can be harsh and bitter. As with so many things in winemaking, balance is key.
If you’re still having a little trouble with the concept of tannin, I suggest a quick exercise. Simply brew yourself a cup of black tea. Go ahead and taste the tea, without adding any sugar or cream. It will taste bitter, and will leave your mouth felling dry. It may even make your lips pucker! You are tasting the tannins in the tea.
As a side note, it has long been known that fatty, high protein foods can help balance overly high tannins. This is where the custom of serving cheese with wine comes from. Historically, cheese was served with wine to help mellow out the harsh flavors in an inexpensive, overly tannic jug wine. Something to keep in mind for your next dinner party!