How is wine actually made?

Hi I’m Antony (Tony) Anderson from Wine Matchmaker and today I want to talk about wine making basics.

In my upcoming blogs and podcasts there are terms I use that you may not be familiar with and a quick introduction to wine making may help explain them, and give you a good foundation to discuss and understand wine. If you would like to listen to the podcast as well please click here.

There is a saying that “good wine is made in the vineyard” and there is a lot of truth to that. The raw material for wine is grapes from the grape vines and generally the better the quality of the grapes, the better the wine.

Ideally the grapes are ripe, disease free, and have the right balance of flavour and sugar, the raw material used to create the alcohol. You don’t want grapes that have too much juice or it will be too dilute and lacking flavour but there needs to be enough juice to make enough wine so it can be sold at a reasonable price. This makes choosing the right time to pick the grapes tricky especially with ever changing weather conditions.

Once the grapes are picked they are brought into the winery where they are crushed to release the juice and at this point the making of white and red wine diverges. White wine is simpler as the skins are discarded and the white grape juice is generally put into stainless steel tanks. Yeast is added and the yeast convert the sugar in the grape juice into alcohol. The process normally takes a few days and the tank needs to be cooled as the process creates heat as well as carbon dioxide along with the alcohol.

If all of the sugar is converted to alcohol then the wine is said to be “dry” which is an unusual term for a liquid but that is the convention. Sometimes the fermentation is stopped before all of the sugar is converted to alcohol and the wine is said to have “residual sugar” and some level of sweetness. The measure of sweetness is grams of sugar per litre of wine with levels above 3 grams per little being noticeable for most people although levels much higher are common in sweet wines.

Once the fermentation is completed the white wine is cooled and the leftover sediment, including dead yeast cells (called lees), is allowed to settle creating a clear wine which most consumer prefer. Strangely most people don’t like drinking cloudy wine. The wine is then normally filtered, bottled and released for sale straight away.

Some white wine e.g. Chardonnay, will be transferred to oak barrels and will spend 6 months or longer in the barrels to impart additional flavour. The wine may also be left on the dead yeast cells to add additional completely and mouth feel and then filtered before bottling.

For red wine the juice and and skins are normally fermented together. This is because the red pigment that makes red wine red is in the skins and needs to be extracted. This is done during the fermentation process, aided by the heat of the fermentation, and the juice and skins are also mixed together to improve the colour extraction. Red Wine fermentation can last much longer than white wines to get as much colour and tannin from the skins as possible depending on the style of wine desired.

I have mentioned the word tannin. Tannin is a chemical compound found in the pips, stalks and skins of grapes that give the wine a drying sensation on the mouth, almost like chewing on the stem of a tree. Although this may sound unpleasant it can give the wine what we call “structure” to balance the fruit flavours and gives the wine ageing potential.

Once the fermentation is completed the red grape skins and juice are pressed to extract the fermented grape juice and the skins are discarded. The fermented grape juice is usually transferred to oak barrels to allow the wine to age and develop further. The ageing time varies greatly depending on the style of wine required and can range from months to years. 

The type of oak is important as it imparts different flavours and aromas to the wine. France oak which can add fruit spice aromas and flavours including cinnamon, clove and nutmeg. American oak is more powerful and can impart aromas and flavours of vanillin and coconut. The amount of these oak aromas and flavors depends on how old the oak is i.e. how many years it has been used, and how long the wine spends in contact with it. New oak will impart much more flavour than older oak and have more of a influence on the final wine. Generally new oak is used for wines that are designed to be aged. Oak barrels also add tannin to the wine which can make a new wine quite “woody” or like chewing on a stick of oak. Once again the balance between the fruit flavours and the tannin is crucial.

Most red wine is fermented dry i.e. all of the sugar is converted to alcohol by the yeast, and although sweet red wines do exist they are much rarer than sweet white wine. This means that red wines are generally lower in sugar although the alcohol in wine i.e. ethanol, is still rich in calories. So wine isn’t a diet drink especially when you take into account the snack food that drinking it encourages.

Once the red wine has spent the required time in oak barrels it is removed from the barrel, filtered and bottled. It will often spend further time in bottle to help it soften before being released for sale. As a broad generalisation red wines will be more expensive than equivalent white wines as they take longer to produce and often need oak barrels that can be quite expensive.

Most wine is bottled in glass bottles as glass is inert and doesn’t impart any flavour or taint the wine. There has been a trend in Australia to seal the bottles which screw caps in the last couple of decades instead of using cork enclosures. This is because cork is obtained from a tree and can contain impurities that taint the wine. The cork can also interact with the wine causing a musty smell that many people find unpleasant. On average wine under cork has a fault rate of around 8%, much higher than screw caps. Screw caps are not as popular in Europe and especially China where wine under screw cap is considered to be cheap wine. This is a pity as many people have a bad assessment of a winery because of faulty corks impacting the wine. Most winemakers I talk to much prefer screwcaps as they believe it shows the wine more accurately as they intended it to be.

There are many more wine making techniques and tricks that winemakers can use but these are more advanced and will be covered in other blogs and podcasts.

So there you have it…the basics of wine making so hopefully in the future you will have a better appreciation for the wine you are drinking and have a better understanding of some wine terms.

For more information pop over to our website Winematchmaker.com.au or go to the Facebook Page where I offer free wine advice. Also look out for our wine course on getting Wine Confident.

I’m Antony Anderson the Wine Matchmaker, thanks for reading and in the meantime enjoy some good wine.