Wine Basics

How Red Wine is Made

Ever wondered what all goes into the winemaking process, from grape to glass?

Although there are many common steps along the way, the journey varies for red, white, sparkling, and sweet wines.

Today, let’s chat about how a little red grape like Pinot Noir transforms into your next delicious glass of red wine.

HARVEST

The grapes have slowly ripened over the course of the growing season and now it is time to harvest.

As the grapes ripened, sugar levels rose and acidity fell. The winemaker must time the harvest to ensure balance between the two, while also paying close attention to the weather. Heavy rains and early frost can pose large problems.

Red grapes are typically picked after white grapes. This gives them a bit more time to develop their sugars, which will eventually turn into alcohol. Any red grapes intentionally being selected for rosé wines will be picked first. And while less common than with white grapes, some red grapes can be left on the vine to freeze and create ice wine.

The grapes can be picked by hand, or by machine. To be picked by hand is much more labour intensive, but it does save the grapes from being jostled around too much. This extra care helps to prevent the grapes from splitting open early and exposing the juice to oxidation early in the process.

SORTING AND CRUSHING

Once the grapes have made their way back to the winery, they must be processed.

Sorting comes first. Large branches and stems, debris, and even little critters, all need to be removed. They can be sorted by hand or by machine, but hand sorting allows winemakers to be very particular about using only the best grapes.

Once the grapes have been sorted, they are crushed.

The crush is perhaps what most people think of when they imagine winemaking. Thankfully, most places don’t use human feet anymore, although some do just for the tradition and fun of it. They even have crushing parties!

Crushing is gentler than it sounds. We don’t want to pulverize the grapes and bruise them, we just want to apply enough gentle pressure to split the skins open so that the juice can begin to escape.

If this was a white wine, we would then move quickly into pressing the grapes of all their juice and removing the skins. But it’s not! For red wine, we want the juice to stay with the skins in order to extract colour and tannin.

FERMENTATION

Now it’s time to make some alcohol with that juice!

Fermentation is the process of creating alcohol. Microorganisms called yeasts feed on the sugars in the grape juice. As they eat, they create alcohol, heat, and carbon dioxide. The carbon dioxide and heat are allowed to dissipate into the atmosphere.

The yeasts can be native to the grapes and vineyard, or commercially purchased. Commercial yeasts are much more common, as native yeasts can be limited.

Fermentation stops naturally once the yeasts have finished consuming all of the grape sugars. The result is a dry wine. Most red wines are fermented dry, but if a winemaker wanted to leave some residual sugar behind, they could stop the fermentation process early.

Why would they do that? Either because they purposely want to make a sweet red wine (uncommon but not unheard of), or they just want to leave a tiny hint of sugar, which will help to hide and smooth out any imperfections. This is quite a common practice in mass-produced, inexpensive red wines, because it makes them more enjoyable for the average consumer.

This process takes place in temperature controlled vessels. Stainless steel is a popular choice because it’s easy to control, but it can also happen in oak barrels. It’s all about what style of wine the winemaker is going for.

Red wines are fermented at warmer temperatures, between 20° and 30° C. The added heat helps to soften tannins (and can soften flavours that start out a bit too aggressive).

Secondary Fermentation

Did you know that almost all red wines (and even some white wines) also go through a second type of fermentation?

Called malolactic fermentation, this process is not caused by yeasts, but by a type of bacteria. This bacteria transforms tart malic acid (think apples) into much softer lactic acid (think milk).

Malolactic fermentation gives wines a buttery quality that generally goes unnoticed in red wines because it is overpowered by the other flavours. It’s much more notable when used in white winemaking.

PRESSING

Once fermentation is done, we press the wine away from the skins.

Pressure is applied from the top of the vessel, and an opening is made at the bottom for the wine to escape.

The wine at the bottom of the vessel is usually the lightest in colour and flavour. A heavy press at the very end squeezes out the very last of the wine, along with a high amount of skin colour and tannins.

FINING AND FILTRATION

Did you know that most wines aren’t vegan? How can that be, if it’s just grapes and alcohol?

During the fining and filtration process, winemakers are trying to get rid of all the leftover bits that they don’t want floating in their wine. Fining is where some animal byproducts come into play.

The most commonly used fining agents are casein (milk protein), albumin (egg whites), gelatin (animal protein) and isinglass (fish bladder protein). These bind onto the unwanted proteins, tartrates, phenolics and tannins. These much larger clumps are then way easier to remove.

If you’re vegan, don’t despair! There are vegan methods of fining, and will usually be noted on the bottle.

Then the wine is filtered, where it’s run through microscopic filters that remove as much as they can.

Fining and filtration can be skipped, but it will result in sediment left in the bottle. While sediment is not automatically a bad thing, it’s less appealing to the average consumer.

BLENDING

While some wineries and winemakers pride themselves on showing off individual grape varietals in their purest forms, many others blend their wines for a variety of reasons.

Artistic winemakers may tackle blending as a challenging science experiment to create a beautifully balanced, nuanced, and complex wine. A sum greater than it’s parts. This is very popular in “old world” wine regions.

Mass distribution brands might choose to blend their wines in order to achieve a consistent taste and style that their consumers have come to rely on.

And still others might blend not just the grapes, but different vintages, in order to ensure they are putting out a quality product (particularly when vintage variation is large and yields are inconsistent). Non-vintage Champagne is a great examples of blending as it spans multiple harvest years and different grape varietals.

We’re talking about it near the end, but blending can actually occur at any stage of the winemaking process.

STORAGE AND MATURATION

After all that activity, it’s time to give that wine some time to rest.

For red wine, the iconic oak barrels are still the most popular choice for aging vessels. Winemakers use oak for two reasons:

1. the oak adds it’s own flavour characteristics to the wine, thus increasing the complexity (and perceived quality) of the wine.
2. the grain of the oak allows for very small amounts of oxygen to enter the barrel. This controlled oxidation helps to integrate all of the different components and make the wine smoother and more palatable.

Not all oak barrels are the same, however! Differences in size, origin, “toast”, and previous use can all have a significant impact. Barrels are a big business!

Once the wine is inside, it is given time to settle before bottling. This can be just a short period of time, or it can be left for years! Some regions even have laws around how long a wine must age in barrel before it’s released.

We should note though that red wine doesn’t have to sit in oak. Actually, oak barrels are very expensive, and some wineries simply can’t afford it, or are trying to cut costs. These wineries will keep their red wines in steel tanks and simply add wood chips or wooden staves in order to mimic the flavours that would normally be added by the barrel.

BOTTLING

The final step is to bottle. Glass bottles are still the most popular means of getting wine to the consumer, but certainly not the only option.

Within glass bottles there are several different common shapes, a wide range of sizes, and the choice between screw cap and cork closures. Cork closures are still a highly popular choice for red wines, particularly the ones that are meant to age.

Aside from glass, there are also plastic bottles, boxed wines, tetra packs, and even aluminum cans!

That’s it, that’s all! Now that delicious red wine is sitting patiently on the shelf waiting for you to buy it and enjoy!

What to read next:

• How White Wine is Made
• Wine Baby’s Guide to: Pinot Noir
• Wine Baby’s Guide to: Merlot
• Wine Baby’s Guide to: Cabernet Sauvignon
• Wine Baby’s Guide to: Syrah/Shiraz