Some of us when we think of winemaking, we see people with bare feet stomping on grapes in a barrel. After all, that’s how it was done traditionally. In fact, that’s how it is still done in some places where those traditional techniques are maintained. Nevertheless, as with anything, the winemaking process has evolved to take advantage of machinery throughout each step.
While some may argue that hand-picked grapes reduce potential damage and improve the selection of grapes, others will note that mechanical harvesters are cheaper and faster. And both are true. So while the methods used may vary between winemakers, the general steps taken in making wine remain the same: harvesting, pressing, fermentation, clarification, and bottling. Of course, some winemakers may add steps depending on the style of wine they want to produce. Regardless, these 5 steps are the backbone of how to make wine.
This is where the magic happens, after all, you can make bad wine from good grapes but you can’t make good wine from bad grapes. The grapes are what hold the potential for the wine, and wine grapes are the only fruit that can annually produce a reliable amount of sugar to yield sufficient alcohol. Likewise, no other fruit has the required acids, esters, and tannins to make a stable wine year after year.
While some vineyards hand-pick their grapes, more and more are taking advantage of machine harvesters because they’re more cost-effective. So how do winemakers know when to pick the grapes? While there is some science involved, a lot of the decision-making is based on good old-fashioned tasting. Once it’s been determined that now is the time to pick the grapes, the mechanical harvester will pluck the grapes off the vines and dump them into bins that will get brought to the winery.
Once the grapes are in the winery, they are sorted and destemmed to be ready to be crushed and pressed. In this process, any rotten or raisined grapes together with the leaves are removed. They may also go through a destemmer, which as the name suggests, removes the stems to leave behind only the grapes.
Once the grapes have been sorted, they are ready to be pressed and crushed. This is where the external skin is split so that the juice can start to run and it allows the sugars to mingle with natural yeast found on the skins. Whilst this step was traditionally done by stomping on the grapes, today it is done mechanically with a heavy spiraled steel roller.
Note: If the winemaker is producing red wine, they will leave the skins in contact with the juices; however, for white wines, the skins will be removed prior to fermentation.
This is where red wine and white wine-making differ. Red wines will be fermented with the skins in contact with the juice, whereas white wines have the skins removed prior to fermentation. Likewise, white wine fermentation often occurs in stainless steel tanks, except for Chardonnay which is often fermented in oak barrels like most red wines. Another difference is that red wines are fermented and then pressed, whereas white wines are pressed and then fermented.
Fermentation, if left to its own devices, occurs naturally within 6-12 hours with the aid of wild yeasts in the air. However, many winemakers intervene in this stage by killing the wild yeasts and adding their own yeasts to provide more control of the finished product. If you’ve ever wondered how wine is made alcoholic, it is in this process. Fermentation is when the sugars get converted into alcohol and it continues until there is no more sugar left. In other words, to control the sweetness level of wine, winemakers have to intervene in this step to stop the fermentation.
Note: Some wines will also go through a malolactic fermentation in which lactic bacteria converts the harsher malic acid to produce lactic acid. This helps create a wine with a softer mouthfeel and overall, a more pleasing palate.
While there are some steps between fermentation and clarification such as stirring the lees for white wine, clarification is the most common next step in winemaking. Within this step is when wine undergoes fining and filtration.
Fining is done to bind tiny floaters in the wine to weigh them down so they can be separated and removed from the bottom of the barrel. Egg whites are the most common fining agent, which is why many wines aren’t vegan-friendly. Nevertheless, there are some vegan-friendly fining agents that some winemakers use such as clay.
Filtration, on the other hand, is when larger particles such as dead yeast cells are removed. Collectively these processes transform a cloudy wine into one that is bright and clear. This clarified wine is then racked into another vessel where it’s likely to then be aged further or bottled to either be aged in the bottle or brought to the market.
This is the home stretch of the winemaking process. If a winemaker decides to age a wine further before putting it out for the market, they may choose to do so in oak barrels, stainless steel tanks, or within the bottles themselves.
Most red wines are aged in oak barrels, either French or American, to impart new flavors to the wine. The oak allows tiny amounts of oxygen to penetrate which helps to ease the tannins in red wine and develop further flavor complexity. Stainless steel tanks are most often used for white wines, however, more winemakers are opting for stainless steel as it’s the more economical option. If they want the flavors that oak provides, many add oak chips to get a similar effect.
Quick fact: American oak often gives off notes of vanilla whereas French oak will provide a subtle spice.
Once a winemaker has determined that the wine is ready (by periodically tasting it), the wine gets bottled and labeled, and that’s the essence of how wine is made. Of course, there are many steps in between and variations depending on the style of wine being produced, the winemaker’s preferences, etc. So next time you open up a bottle of wine, revel in how each aspect of it, from the mouthfeel to the flavors to the color are all intentional choices by the winemaker.