Red wine is produced by fermenting red wine grapes. It gets the red colour and grippy mouthfeel from the time it spends with the grape skins. Fermentation is the process where the sugars of the grape berry are turned into alcohol with the help of yeasts.
In a nutshell
Once the red grapes are picked from the vineyard and are taken to the winery, the winemaking process starts. The fermentation starts while the grape skins are still in contact with the must (grape juice). That’s when colour and tannins are extracted, in the same way tea is made. After pressing, the wine then is aged for a few weeks or even a few years, before being clarified, filtered and bottled. Read about our red wine recommendations with our Red wine 101 guide [link to article]
Phase 1: Harvesting of the red-wine grapes
When it’s time to harvest the red grapes, there are a lot of parameters that should coincide. First of all, the sugars have to be at a desirable level, while balanced with enough acidity. Also, the skins of the grapes have to be ripe. Ripe skins give smoother tannins to the wine.
Sometimes, sugars accumulate faster than the skins ripen. Climate change is making this more common, resulting in red wines tending to have higher and higher alcohol levels.
Harvest may be done by hand or by machine. It depends on cost, the producer preference and the winemaking technique to be used.
Phase 2: Destemming and Crushing of the grapes
Once the grapes reach the winery, they are typically destemmed, crushed and transferred into red wine fermentation tanks. The stems can give a bitter mouthfeel, so many producers choose to remove them.
Alternatively, the grapes can go through carbonic maceration, which gives fruitier wines. Here, the grapes must be hand-harvested and are transferred whole, with care not to crush the berries, into the fermentation tanks. It is also referred to as whole cluster fermentation.
Phase 3: Red wine fermentation
Red wine fermentation is done while the grape skins are in contact with the must. This process is called maceration.
Anthocyanins and tannins are responsible for the wine colour and mouthfeel and are found in the skins of the grapes. When skins stay with the must, these natural compounds are extracted into it, just like when making tea.
Maceration can last from a few days to many months, depending on the style the winemaker wants to produce and the grape variety.
Phase 4: Pressing of the grapes
Once there is enough colour and tannins extracted into the must, it is transported to the press.
The pressing of red wines can be done during fermentation or after. The must or wine is then pumped into closed fermentation tanks or barrels, to finish the fermentation there and start maturing.
Phase 5: Malolactic Fermentation (MLF) of red-wine grapes
Red wines are usually aged for longer periods. To do that they need to be as stable as possible so that they won’t spoil.
During Malolactic fermentation (MLF), lactic acid bacteria consume malic acid and transform it into lactic acid. Lactic acid feels more creamy, less acidic and is more stable microbiologically.
MLF is favoured by the higher pH of red wines and the higher fermentation and storing temperatures, compared to white wines. As a result, most red wines go through malolactic fermentation.
Phase 6: Red wine racking
During racking, any sediments that have developed in the wine are removed.
In red wine, racking is performed after MLF is completed. These sediments may result in off flavours if they remain in the wine. Sediments may include inactive yeast and bacteria, as well as polymerised anthocyanins and tannins.
There is always new sediment in red wines. Some winemakers choose to remove it regularly, while others leave it for long periods of time. Traditionally, racking is performed under candlelight, so that the producer can clearly see when the sediments start and stop the wine transfer.
Phase 7: Red wine ageing and maturation
On average, red wine is aged more than white or rosé wines. Ageing usually happens in oak barrels for the most high-end wines.
Red wine generally needs ageing for the tannins to become smoother. While the wine is maturing, it not only gets a balanced mouthfeel, but the flavours also become more complex.
Many red Italian wines require a minimum ageing time in oak, in order to qualify for the regional appellation (DOC or DOCG), like Vino Nobile di Montepulciano DOCG in Tuscany.
Phase 8: Red wine blending
Blending and red wine go hand by hand. Since it is so difficult to harvest the red grapes when all sugars, acid and tannins are perfectly balanced, winemakers have turned to blending.
Blending may include different varieties, like with the Super-Tuscans and the wines of the Valpolicella. Alternatively, the wine can be from a single varietal. Then, many different vineyard parcels are used to bring the wine to balance. That’s what many producers in Piedmont prefer to do with Nebbiolo when making Barolo or Barbaresco.
Phase 9: Red wine fining
Since red wine is typically aged for a while, fining to reduce instabilities is not really needed. However, it is sometimes used to improve the taste of the wine. Sometimes tannins don’t become smooth, even after long ageing. That’s when the winemaker may choose to use fining agents that bind to the astringent tannins and help them precipitate.
Tannins bind very well with proteins, so traditionally egg white was used for red wine fining. Don’t worry, the sediment is removed by a final racking and there isn’t any trace of egg whites in the wine. There are however industrial products that are Vegan certified and are most commonly used by commercial wineries.
Phase 10: Red wine bottling
Finally, it is time for the winemaker to choose when the red wine is ready to be bottled. That is after blending and fining have been performed.
Traditionally red wine is bottled in 750 mL glass bottles. The preferred closure for red wine is the cork stopper. Cork suits red wine especially well since it allows some oxygen to go through, allowing the wine to develop inside the bottle. Cork closure is also mandatory for most Italian red wine appellations.
The wine may be aged inside the bottle by the producer or it can be sold after bottling. Keep in mind that not all red wine is meant to be aged and some are crafted to be drunk young.
FAQs
How is red wine made step by step?
The red grapes are crushed but are not immediately pressed. The coloured grape skins are left to ferment with the must, and that gives red wine colour and structure. After fermentation, the wine is pressed and often aged in oak vessels. It is then blended, fined and bottled.
H3:
How long does it take to make red wine?
Red winemaking takes longer than white wine. Red wines are typically released six months to two years after the harvest, but some styles may be sold after five or more years.
Are red wines filtered?
Some of the red wines that are released early are filtered. The red wines that have matured in the winery don’t need to be filtered, since all the instabilities have precipitated. These might undergo a coarse filtration to make sure no large sediments go into the bottles.
