PART 1: GROW GRAPES & HARVEST THEM
A grapevine begins to produce grapes after its third year. Regardless of the vine's age, grapes only grow on stalks that are one year old. Because of this, viticulturists prune their vineyards back every year to encourage new growth.
PART 2: CRUSHING THE GRAPES
Wine grapes are usually destemmed to reduce harsh vegetal-tasting tannin. Sometimes wineries have long sorting table conveyor belts to further check for leaves or bad grapes. Then the grapes are crushed and put into an environment that is conducive for the yeast to thrive. Red wines get their deep colour from being fermented with the skins.
PART 3: FERMENTING SUGAR INTO ALCOHOL
The fermentation starts when a yeast culture grows and consumes the available sugar and turns it into alcohol. There are many different kinds of yeast strains that either happen naturally or are added (called inoculation) to control the flavour. Red wines are typically fermented at warmer temperatures than white wines. Also, red wines are usually fermented until all the sugar is consumed, creating a dry wine.
WHY DO WINES GET AGED IN OAK BARRELS?
Before there were glass bottles (the 1600s and before), most wines were stored and sold in wooden barrels. In fact, paintings from around this time period often show wine barrels strewn about. And, while we've outgrown the necessity for barrels to store and transport wine, we've come to acquire a taste for it. Oak barrels are an integral part of modern winemaking.
HOW DO OAK BARRELS HELP WINE?
Oak offers three major contributions to wine: It adds flavour compounds - including aromas of vanilla clove, smoke and coconut. It allows the slow ingress of oxygen - a process which makes wine taste smoother and less astringent. It provides a suitable environment for certain metabolic reactions to occur (specifically Malolactic Fermentation) which makes wines taste creamier.
WHAT FLAVOURS DOES IT ADD?
Unlike beer, wine does not allow flavour additives (i.e. coriander, orange peel, etc.). Thus, oak has become an accepted way to affect the taste of wine. When added to wine, oak flavours combine with wine flavours to create a wide variety of new potential flavours.
FLAVOUR COMPOUNDS FROM OAK
THE DIFFERENCES OF NEW VS USED OAK AND AGEING
Just like tea, oak flavour extraction is reduced each time it's used. You'll also notice that ageing periods vary depending on the winemaker's preference as well as the type of wine
DIFFERENT KINDS OF OAK USED FOR WINEMAKING
There are 2 primary species preferred for winemaking: Quercus alba or American white oak and Quercus Petrea or European white oak. Each species offers slightly different flavour profiles. Additionally, the climate where the oak grows also affects flavours. So, for example, wines aged in Quercus Petrea from Allier, France will taste different from wines aged in Quercus Petrea from the Zemplen Mountains forest in Hungary.
DIFFERENCE BETWEEN AMERICAN AND EUROPEAN (FRENCH) OAK
The major distinguishable physical difference between the wine oak species is its densitv. European oak tends to be denser (closer spaced rings) which has been suggested to impart fewer oak lactones and oxygen than American oak Generally speaking, American oak is ideal for bolder, more structured wines (Cabernet Sauvignon, Shiraz) that can handle American oak's robust flavours and oxvgen ingress, whereas European oak is ideal for lighter wines (such as Pinot Noir or Chardonnay) that require more subtlety.
PART 4: MATURATION. FINING. FILTERING AND BOTTLING
Red wines age for anywhere from 4 months to 4 years before being bottled. During ageing, "fining' often occurs to make the wine clear. Wine additives are often used that glom onto dissolved proteins. After fining, filtration happens, and the wine gets bottled. Some red wines are not fined or filtered to add more body. Unfiltered wines should be decanted before drinking.