Wine is an everyday drink that has been around for seven thousand years, and it is made in pretty much the same way as it was originally. Wine is such a normal thing that we don’t stop to think about the magic that transforms grape must into wine. It’s no divine mystery, even if the taste is divine. If you want to know how wine is made, step by step, then here is your lesson.
After cultivating the vineyard throughout the entire vine cycle, generally speaking, the basic steps involved in winemaking are the following: harvest, destemming, crushing, maceration, alcoholic fermentation, pressing, maturation or aging, clarification and bottling.
In winemaking, these steps are usually followed for white, rosé and red wines but may happen in a different order depending on the style of wine. White wines are made in a different order to red wines and we can explain why.
Once the grapes have been harvested, which might be done mechanically or manually, they are immediately taken to the winery to avoid any possible oxidation that could alter the organoleptic characteristics of the wine.
It’s important to remember that the time of the harvest usually coincides with the hottest time of the year, the summer. This is why many wineries decide to carry out night harvests. Harvesting at night avoids having to deal with the high temperatures of the day and their potential consequences on the fruit.
White wines can also be made from red grapes (blanc de noirs) but we will explain the most common method, which uses white grapes.
When the grapes reach the winery, the bunches are destemmed, which means the berries are stripped of their “wooden skeleton” and of everything that isn’t the fruit, leaving the berries loose and free of other debris. The bunches might also pass over a “selection table” before going to the destemming machine. At the sorting table, expert personnel remove all materials (leaves, stalks, vine shoot remains, etc.) that are not the fruit. They also remove any grapes that are not in good condition, which contributes to an even better quality final product.
The grapes are crushed to break them up and extract the juice, which will facilitate the start of fermentation. Crushing and pressing are not the same thing and are often a source of confusion. Crushing involves a gentle pressure while pressing uses a stronger pressure.
Crushing does the same thing that was traditionally achieved by treading the grapes: gradually and gently bursting the berries so that only the best characteristics of the fruit come to the surface.
One of the differences between the process of making white wines and red wines is that the pressing and crushing are carried out at different times.
To make red wine, crushing is usually carried out after the harvest reaches the winery and after destemming. Pressing is carried out at the end of fermentation.
To make white wine, the grapes are pressed after destemming and before fermentation begins. It should be noted that the first must that comes from pressing is always the best and that the gentler the pressing, the better the quality of the resulting must. Excessive pressing can result in the extraction of more bitter components that will not benefit the wine-to-be.
In some cases the winemakers crush the grapes and leave the must to cold-macerate (to prevent fermentation from starting) for a few hours with the mixture of pulp and grape skins. This produces white wines with more body and aromas, but this step is optional. Following this method, a white wine that has undergone a short skin-contact maceration must be racked before fermentation begins.
This process of cleaning the must prior to fermentation is known as “racking”. To do this, the must is kept cold so that fermentation doesn’t start prematurely, and is left to settle so that the particles can fall to the bottom of the tank. The clarified must is removed through a side hole in the vat, so the particles stay at the bottom without affecting the fermentation process.
When making red wines, maceration is necessary because this is how the wine gets its characteristic colour thanks to the anthocyanins, compounds (polyphenols) found in the skins of the red grapes. These compounds, as well as colouring the must, also provide particular organoleptic characteristics to each wine.
This is the magic moment. During fermentation the must is transformed into wine thanks to the action of the yeasts, which feed on the sugar contained in the juice to generate alcohol, carbon dioxide and energy.
For the magic to happen, yeasts can be inoculated or nature itself can start the process using the yeasts that are already on the grape skins and have been naturally integrated into the must.
During fermentation, the yeasts not only transform the must into wine but they also add aromas and other organoleptic properties.
When fermentation has finished, the yeasts die. Some winemakers tend to leave them (the famous lees) in contact with the wine for a while as this gives more volume and flavour.
At this point the must has already been transformed into wine. When it comes to white wine, this liquid is racked, which means it is transferred from one container to another in order to separate the clean wine from the solid residues generated during fermentation.
Red wine is racked and then pressed. The press is used to extract the wine accumulated in the solid remains from the fermentation process.
And now comes the time when winemakers decide whether to add sulphites or not. Adding sulphites can help to prevent other microorganisms changing the characteristics of the wine.
A common practice, especially in red wines, is to apply a process called malolactic fermentation following alcoholic fermentation, which is caused by the yeasts. Malolactic fermentation can either happen naturally or be brought about. At this stage of the vinification process, what winemakers are looking for is to use a series of bacteria to convert a hard acid, like malic acid, which is present in the wine (similar to the acid you can taste in an apple) into a softer acid like lactic acid (which you find in milk and yoghurt). This process has a direct impact on the taste of the wine and can help refine its flavour
From this moment on, the wine can have sulphite added if the winemaker chooses to, and then it is clarified and bottled ready for sale if they are making a young, unaged wine.
If the aim is to make an aged wine, this would be the moment the wine is transferred to the barrel or tank chosen for maturation. Barrel aging gives the wine aromas and flavours and refines its tannins and acidity.
Clarification and filtering
In order to have a final wine that is bright and clean, refining agents are used to help capture the small solid particles that have stayed in the liquid. If this doesn’t fix it, winemakers might then use filtering techniques that involve pouring the wine through a thin membrane.
Finally the wine is bottled ready to be sold, although wineries usually leave bottled wine to rest in the cellar for a short amount of time to stabilise and refine it before it is sent out. Some red wines, either through regulations in the denomination of origin or through the winemaker’s choice, might spend a few years in the cellar before being released for sale.
It goes without saying that each winemaker, as well as following the fundamental steps of winemaking that we have described here, can also make different decisions that we haven’t covered here but that can give each bottle its own personality and the winemaker’s unique touch.
We wanted to take this opportunity to describe how a wine is made step by step in a general and easy to understand way, and, as you can see, the winemaking process, as well as being interesting, is delicate. But understanding this process helps us to understand and appreciate what we find inside each bottle of this very common companion: wine, something we love having on our tables and that is often there for us during life’s special occasions and joyful moments. Cheers!