The wine making process has both compulsory and optional stages in order to produce the final bottles. This section will look at the choices that can be made and the impact on the final wine.
You may wish to see the guide on Grape growing before reading this.
Once the grapes are picked it's important to limited the amount of interaction that occurs with oxygen, otherwise oxidation can occur. Covering with sulphur dioxide can protect the grapes as it acts as an antioxidant and antiseptic. From here onwards it’s the wine maker’s decision on how to treat the grapes.
This is a method to make fruity red wines that are light in style commonly used in Beaujolais. The grapes are covered in carbon dioxide which allows the production of alcohol to start occurring inside the grapes, this limits the juices contact with the skins reducing tannin. Once the grapes have produced alcohol it splits the skins, the juice is pressed and fermentation begins normally. There are a variety of different styles of carbonic maceration all with similar principles which result in fruity low tannin wines.
It is commonly overlooked, but temperature can make a significant difference when producing wine. Fermentation produces heat as a by-product and if this isn’t controlled then the temperature levels will continue to rise, this has a big impact on the fruit flavours in the wine. Vessels such as stainless steel allow the producer to control temperatures. Wines that are designed to be fresh, floral and fruity will benefit from cooler temperatures e.g. New Zealand Sauvignon Blanc.
All reds and some whites undergo this process. It occurs after fermentation, lactic acid bacteria convert the harsh malic acids into smoother lactic acid. This produces obvious flavours of butter, cream and cheese which can be extremely pleasant in some styles of wine.
Lees contact and Stirring
Aka. Sur lie and Bâtonnage
This principle provides bread, biscuit, pastry, brioche notes associated with the wines secondary characteristics. The yeasts that cause the wine to ferment (and produce alcohol) can produce complex compounds when they break down and the flavours are incorporated in the wine. It's not only flavours that are introduced the body of the wine can become fuller and it can increase stability and reduce oxidation risk.
Oak barrels can be used for maturation for red wine or fermentation and maturation for white wines. The use of oak can have a major impact on the wines' final aroma, flavour and tannins. There are multiple options when it comes to this, the size, the age and the type of oak. The smaller, newer barrels will have the biggest impact of flavour on the wine, however, they are also the most expensive. Larger, older barrels can be used for maturation allowing a smaller impact from oxygen helping to age the wine and develop tertiary characteristics. French oak provides vanilla, spice and toasty notes whereas American oak concentrates on coconut and sweet vanilla. Another cheaper style is from Hungary but it is less commonly used in the best wineries. Different barrels are often blended to get the best combination of flavours. Oak chips or staves can also be used to impart flavour into the wines.
Aka. Passito, Straw wine, Strohwein
This is a method often used in the production of sweet wines but it can also produce some wonderful dry wines too. The grapes are picked when ready and then dried, either by hanging or by lying on straw mats. The principle is to concentrate the flavours, acids and sugars in the grape that can then go on to produce a powerful, complex bottle.