Wine Basics

How White 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 white grape like Chardonnay transforms into your next delicious glass of white wine.

HARVEST

The growing season is over and it’s time for harvest.

Over the course of the season, grapes ripen on the vine. During the ripening process, sugar levels rise while acidity falls. The winemaker must decide when to harvest the grapes in order to ensure they have the perfect balance between the two.

White grapes are typically picked before red grapes, because we want the acidity to remain high. The exception would be grapes that will be used for “late harvest”, botrytized, or ice wines.

And although most white wines are made with white grape varietals, we should note that it is possible to make white wine using red grapes, like pinot noir.

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.

PROCCESSING, CRUSHING AND PRESSING

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

First they are sorted. Large branches and stems, debris, and even little critters, all need to be removed. Pickier winemakers will also take the time to sort out unsuitable grape clusters, so only the best grapes are being used.

(Story time: I once participated in a sorting and was trying to remove as much as I could. I saw a very large spider. I tried to get someone to grab it. The winemaker calmly watched as it passed by and announced “extra protein!” This is common. You can’t catch ’em all!)

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.

Crushing occurs when the grape skins are first split open and the juice starts to get released.

After the initial crush, we press the grapes to extract the rest of the juice.

For white wines, these steps need to be accomplished relatively quickly. Leaving the juice in contact with the skins and seeds will extract colour and tannin. While these thing are desirable in red wine, they are significantly less popular in white wine (unless you are specifically producing “orange wine”.)

FERMENTATION

Now that we’ve got the juice out, it’s time to make some alcohol!

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 is allowed to escape into the atmosphere, unless you are trapping it to make a carbonated wine like Champagne.

These 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. But if a winemaker wanted to leave some residual sugar behind, they can stop the fermentation process early.

This entire process takes place in temperature controlled vessels. Stainless steel is the most popular choice for white wines, but fermentation can take place in large concrete eggs or oak barrels. It’s all about what style of wine the winemaker is going for.

White wines are fermented at cooler temperatures, between 12° and 15° C, in closed tanks to reduce oxygen exposure. Both of these factors help to preserve the more delicate fruit and floral aromas of white wine.

WINEMAKING CHOICES

Lees

Once fermentation is complete, the yeasts die and fall to the bottom of the vessel. This forms a layer of dead cells that we call “lees”.

The winemaker must then decide if they want the wine to remove the lees, or leave them in.

For the majority of white wines, the lees are removed. This is especially true for aromatic grape varietals, as we want their natural aromas to shine through.

But for some, the wine is left in contact with the lees in order to build complexity and add weight to the wine.

While maturing, the lees are continuously stirred up to mix back in with the wine throughout the maturation process. The result is added flavours of bread and biscuits. This process is called battonage and is sometimes seen on the label as “sur lie”.

Malolactic Fermentation

Another choice the winemaker must make is whether or not to let the wine undergo a second stage of fermentation.

This fermentation is not caused by yeasts this time, but rather a type of bacteria. This bacteria transforms tart malic acid (think apples) into much softer lactic acid (think milk). Hence the name: malolactic fermentation.

Nearly all red wines undergo malolactic fermentation, but in white wines it is often stopped in order to preserve the more delicate aromas and flavours. If not stopped, malolactic fermentation gives white wines a buttery flavour that goes unnoticed in red wines.

The choice to utilize lees contact and malolactic fermentation often go hand-in-hand for white wines that are meant to be bold and full bodied.

An excellent comparison would be an oaked Chardonnay vs. an unoaked Chardonnay. The oak isn’t always the only difference.

FINING AND FILTRATION

Finally, once the wine is ready to move on to the final stages, it is fine and filtered.

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. Because of the fining process, most wines technically aren’t vegan.

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.

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

The wine is sent through microscopic filters that remove everything but the liquid.

BLENDING

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

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.

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.

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.

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.

STORAGE AND MATURATION

Now we need to give that wine some time to rest. It’s been through a lot!

White wines can be stored for just a few months, or they can be left to mature for much longer before release.

During this time, most white wines are stored in inert vessels like stainless steel tanks or concrete eggs. Because they won’t affect the flavours of the wine, it doesn’t need to sit there long before release.

Oak barrels might be the vessel of choice for full-bodied whites that have undergone malolactic fermentation, lees contact, or both. The use of oak is another way for the winemaker to add complexity of flavour. Because wood is porous, it also allows for a small amount of oxygen exchange, which helps to soften the wine.

BOTTLING

Finally we are ready 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.

Beyond glass, there are also plastic bottles, boxed wines, tetra packs, and more recently cans!

While traditional glass bottles still have the strong hold, there is definitely a swing in the direction of smaller, more convenient packaging to allow for individual consumption without committing to a whole bottle.

And that’s it! Now that delightful white wine is sitting patiently on the shelf waiting for you to buy it and enjoy!

What to read next:

• Wine Baby’s Guide to: Chardonnay
• Wine Baby’s Guide to: Pinot Gris/Grigio
• Wine Baby’s Guide to: Sauvignon Blanc
• Wine Baby’s Guide to: Riesling
• Wine Baby’s Guide to: Viognier