Rows of grape vines in a farm

In 2017, archeologists discovered a collection of jar fragments in an ancient village near the Georgian capital, Tbilisi. The jars, which had lain undisturbed for almost 8,000 years, contained unmistakable evidence of wine making and were decorated with images of grape clusters and a dancing man. They are the earliest known evidence of grape wine production. 

Similar jars, known as qvevri, are used to this day to store Georgian wine made in the traditional manner. Grapes, stems, and seeds are crushed together and left to ferment. The basics of modern wine making would be recognizable to Neolithic Georgian vintners, but techniques have been refined over the millennia to support wine production on an industrial scale. 

In this article, we’ll explore the wine-making process, including the main steps on the journey from vine to glass. 

1. Grape Harvesting

Grape harvesting is the first step in making wine. The grape farmer — also called the vigneron — chooses when to harvest grapes, which affects the wine’s flavor, aroma, and quality. Sugar and acidity levels determine the optimal time for grape harvesting, and instruments like refractometers are commonly used to measure them, ensuring that red and white grapes are harvested under ideal conditions.

Grapes destined for red wine and white wine are usually harvested at different times: Red grapes are picked later in the season when they have a higher sugar content, while white grapes are harvested earlier to preserve their acidity.

2. Crushing, Destemming, and Pressing

Crushing breaks the grape’s skin to release the juice inside, which initiates fermentation. Mechanical crushers are most commonly used, but foot-treading is still employed in some wineries. The degree of crushing can impact the wine’s flavor and tannin content. Lighter crushing is often used for wines aiming for a more delicate profile.

Destemming removes the grape from its stem to prevent tannins and other compounds in the stem from imparting a bitter or vegetal character to the wine.

In red wine production, grapes are commonly destemmed and frequently crushed, although some types of red wine are fermented with whole grapes. 

White wine grapes, in contrast, are not usually crushed or destemmed but are immediately pressed. Pressing extracts the grape juice and separates it from the skin and stems. For white wines, winemakers aim to prevent the extraction of tannins and other components from the skins and stems, although some rosé wines are made with the skin intact to add color. 

3. Primary Fermentation

Primary fermentation, or alcoholic fermentation, is the core of wine production. Wine yeast metabolizes grape sugars, producing alcohol and carbon dioxide gas as byproducts. The critical distinction between red and white wines lies in the fermentation process: Red wine ferments with grape skins, allowing for the extraction of tannins and color that define their character.

Winemakers can use naturally occurring or commercially cultivated yeasts. Natural yeasts provide unique regional characteristics but risk inconsistent results. Commercial yeasts offer reliability and are engineered for specific flavor profiles.

The fermentation stage occurs in containers ranging from stainless steel tanks, which offer a neutral environment and precise temperature control, to oak barrels that enable micro-oxygenation and introduce complex flavors such as vanilla, caramel, and spice.

4. Free-Run Wine Extraction and Red Wine Pressing

In red wine production, the post-fermentation phase centers around the extraction of free-run wine and the subsequent pressing of the grape skins. Free-run wine is the initial juice that flows freely from the fermented grapes, generally yielding a wine with milder tannins and flavors.

Once the free-run wine is collected, a mechanical press squeezes the remaining juice from the skins. The liquid is richer in color, tannins, and flavors, resulting in a more concentrated wine. Pressed wine is frequently aged independently and may later be blended with the free-run fraction to achieve a balanced and complex final product.

5. Malolactic Fermentation and Aging

Many wines undergo a secondary, malolactic fermentation. Bacteria transform malic acid into lactic acid, reducing the wine’s tartness and adding a richer, more velvety texture. In red wines, it’s a common practice aimed at mellowing tannins and adding depth. Some white wines, notably Chardonnays, undergo malolactic fermentation to achieve a buttery texture.

After fermentation, wines are typically aged to improve and enhance their flavor, aroma, and overall complexity. Aging allows the various components in the wine, such as acids, sugars, tannins, and phenolic compounds, to integrate and harmonize. 

Aging can soften red wine tannins, making the wine less astringent. In red and white wines, aging develops tertiary flavors that complement the primary fruit flavors present in young wines. These can include leather, tobacco, and earth notes in red wine and nutty or honeyed flavors in white wine. 

White wine is generally aged for shorter periods, ranging from a few months to a year or two, especially if the goal is to preserve fruity and floral aromas. Some full-bodied whites like Chardonnay can benefit from longer aging periods, up to several years, to develop complexity.

Red wines often undergo longer aging, typically from one to three years, although some premium wines may be aged for even longer periods — up to decades in some instances. The aging time allows the tannins to soften and the wine’s flavors to integrate.

6. Blending

Blending involves mixing various wine batches, potentially from different grape types, to achieve a balanced and cohesive final product. While red wines are frequently blended to enrich complexity, combining elements like fruit intensity, tannins, and acidity, white wines are generally blended more conservatively, aiming for a balanced interaction between fruitiness and acidity.

The art of blending extends beyond merely mixing different grape varieties. It may include blending wines from different harvest years, vineyard locations, or even wines aged in different types of barrels. These techniques enable winemakers to produce consistently high-quality wines that meet the expectations of their brand or comply with regional wine regulations.

7. Clarification: Fining and Filtration

Before a wine can be bottled, it undergoes clarification to eliminate impurities and suspended particles, enhancing its appearance and stability. The two main approaches to clarification are fining and filtration. Fining uses substances like bentonite, egg whites, or isinglass to attract and bind particles, causing them to settle at the bottom of the tank for easy removal.

Filtration, in contrast, uses a physical barrier like a membrane filter to separate impurities from the wine. This technique is frequently applied to white wines that demand a high degree of clarity and brilliance.

Each method comes with its own set of trade-offs. Fining may inadvertently strip the wine of some flavors, while filtration needs to be executed meticulously to avoid the risk of oxidation. The choice between the two is contingent on the wine's specific needs and the winemaker's goals.

8. Bottling and Bottle Aging

Bottling signifies the end of the wine production process and the beginning of its journey to consumers. During this stage, wine is transferred into wine bottles, which are corked and capped with a protective seal to prevent oxidation. 

After bottling, some wines will continue to age and develop, particularly complex red wines and some full-bodied whites, which can mature and improve when stored under the right conditions. 

Bottle aging enables the slow interplay of flavors and tannins, leading to a nuanced and integrated wine vastly different from its freshly bottled state.

Conclusion

We’ve covered eight of the most common processes wines undergo on their journey from grape vines to your glass. But the wine production industry is incredibly diverse, and many other techniques are used to produce the desired quality in a bottle of wine, including the Méthode Champenoise, which introduces Champagne’s famed bubbles, and fortification, which gives us wines like Sherry and Port.

At Wine Deals, you can buy thousands of different wines produced using many different methods, so you’re sure to find the perfect bottle for any taste or occasion.