September Back to Wine School: How Red Wine Is Made

September has that unmistakable back-to- school feeling. Fresh notebooks, new routines and the realization that there are probably a few things we should have paid more attention to the first time around. So this month, we are going back to wine school.

Instead of memorizing wine regions or grape varieties, let’s start with the basics: what actually happens when grapes become red wine? The biggest difference between red and white wine is what happens to the grape skins. For most red wines, the grapes are fermented with their skins, which is where much of the wine’s colour and tannin come from.

When grapes arrive at the winery, they may be crushed and destemmed, or some or all of the stems may be left intact. The winemaker then places the grapes into a fermentation vessel. Yeast consumes the natural sugar in the grape juice and converts it into alcohol and carbon dioxide.

As fermentation takes place, the grape skins rise to the surface and form what is called a cap.

Winemakers need to keep that cap in contact with the juice to encourage extraction. They might pump wine over the top of the cap, called a pump-over, or physically push the skins back down, known as a punch-down.

This is where winemaking becomes particularly interesting. The amount of time the wine spends with the skins, along with temperature and extraction techniques, can influence the colour, tannin and overall structure of the finished wine.

If you have ever tasted a Beaujolais that was incredibly juicy and bursting with fresh fruit, you may have experienced the effects of a technique called carbonic maceration. With carbonic maceration, whole grapes are placed into a vessel filled with carbon dioxide. Because the grapes remain intact, fermentation begins inside the individual grape cells. This is known as intracellular fermentation.

Rather than extracting large amounts of tannin, the technique tends to emphasize bright fruit and aromatic character. Think strawberry, cherry and raspberry, sometimes with a distinctive candied quality. It is particularly associated with Gamay from Beaujolais, although the technique is used in other regions and with other grapes too.

Then there is a completely different approach to concentrating flavour: appassimento, the traditional technique behind Amarone della Valpolicella. Instead of sending freshly harvested grapes straight into fermentation, selected grapes are dried for several months on racks or mats in ventilated drying rooms. As the grapes lose water, their sugars, acids and flavour compounds become more concentrated. The partially dried grapes are then crushed and fermented, resulting in a wine that is typically rich, full-bodied and high in alcohol, with concentrated flavours of dark fruit, dried cherry and spice.

Once alcoholic fermentation is finished, the wine may be pressed and then undergo malolactic conversion. This process transforms sharper malic acid into softer lactic acid, helping create a rounder texture. After that, the wine may be aged in stainless steel, concrete or oak, depending on the style the winemaker wants to create. Oak can also influence the wine’s texture and aroma while allowing gradual oxygen exposure that helps soften tannins.

So the next time you drink a red wine, think beyond whether you simply like it. Ask yourself: Is the tannin firm or soft? Does the fruit taste fresh or concentrated? Is the wine light and juicy, or structured and powerful? Those characteristics are clues to how the wine was made.

Welcome back to wine school. Class is officially in session. Cheers!

Stephanie Gilker is the founder of Saint Wine Society, curating polished wine tasting experiences and Champagne service across Alberta. She holds WSET Level 3, French Wine Scholar, and Master of Champagne certificates, bringing expertise, creativity, and elegance to every glass.