How grapes become wine

Show some skin, Sugar.

Before we get too far, let’s answer this simple question. What even is wine?

The technical definition of wine is a “drink made from fermented fruit.” In practice, you can really make wine from any fruit – strawberries, rhubarb, cherries, plums! But, most commonly, wine is made from fermented grapes.

Grapes are ideal for wine-making because of their high sugar content and balanced acids and tannins. These qualities make grapes ideal for producing a fermented beverage that not only tastes good, but ages well (we’ll talk about aging in another article).

So, how do grapes become wine?

While grapes are picked differently according to available technology, regional traditions, time of year, and even just personal preference, producers take the following steps when producing their wine.

1. Pick The Grapes

What is wine without grapes? The first step of the process is to acquire the goods. People, or machines, cut grapes (stems and all) from the vines and collect them into large bins that are then transported to a crushing pad.

Small wineries especially prefer that the grapes are harvested by hand as this method of production tends to yield superior results to wine made from machine-cut grapes. While manual harvesting has high costs, namely in efficiency and intensity of labor, humans can control the quality of the grapes picked – resulting in a better overall wine.

Depending on the harvest at hand, grapes can be picked night and day. This not only increases overall efficiency and improves working conditions (lower night-time temperatures), but it also allows for wineries to ensure that they are picking the grapes at the most stable sugar levels – ie. the perfect level of ripeness.

2. Crush The Grapes

Once the grapes are picked, they are de-stemmed and crushed.

For white wine, grape juice is extracted from the skins using a machine called a press (exactly what it sounds like) and then transferred into a tank. After the sediment has sunk to the bottom of the tank, the juice is then “racked,” which means that the sediment is filtered out from the grape juice, and transferred to yet another tank to start the fermentation process.

For red wine, crushed grapes and skin alike go into the tank to start the fermentation process. *Fun fact – the skin to juice contact is what makes red wine, red. The juice itself, regardless of whether it is a red-skinned or white-skinned grape, is almost always clear.

3. Fermentation Begins

Yeast is added to the vat of grape juice (and skins, if it’s a red wine), and the fermentation process starts…

Not to get all scientific on you, but the simple formula for fermentation is this:

Yeast + Sugar = Alcohol + CO2 (+ Heat)

—> The yeast consume all (or most) of the sugar which produces alcohol.

—> Carbon dioxide (CO2) is released —> For red wines, the carbon dioxide pushes the grape skins to the top of the vat. In order to ensure that the juices stay in contact with the skins (and get their red color), winemakers will “punch down” or “pump over” – which essentially just means that they re-mix the grape skins and the grape juice.

—> Besides alcohol and CO2, the fermentation process naturally generates heat. Temperature can actually have a positive effect on the flavors, colors and tannin-levels of the wine, but winemakers have to make sure that fermentation doesn’t happen too quickly. Nothing is rushed in this phase. If fermentation happens too quickly (ie. sugar converts to alcohol at too high of a temperature), some of the wine’s key qualities can be missing. Because of this, some winemakers will even try to decrease the temperature in order to retain terroir. Red wines are typically fermented at higher temperatures, 20-30 degrees C, and white wines between 7-16 degrees C.

4. Aging & Bottling The Wine

The requirements of wine aging are vast, complicated, and different depending on the type of wine you are producing. Before wine even gets bottled (and aged in bottle), a winemaker must make the choice about whether or not to…

• Age for months, or years

• Age in stainless steel, or oak

• Age in new oak, neutral oak, or used barrels

• Age in American oak, or French oak

• Age in a toasted (ie. charred) barrel

Once the winemaker is satisfied with their wine, it’s time for the next step…bottling.

Whether the wine is then drunk immediately, or saved like precious cargo for the next 30 years, really depends on whoever bought the bottle. Maybe you want to save it for a special occasion like a holiday dinner or an anniversary, or maybe you treat yourself everyday (couldn’t we all use a little bit more of this?) What’s your “special occasion” bottle? Tell me in the comments!