Much like the grape grower, the winemaker has a lot of choices when it comes to making her grape juice into wine. We’ll talk about the basic process first and then go over some of the optional techniques a winemaker can use later. As grapes are picked they are placed in bins to be brought to the winery. Most, but not all, wineries choose to empty these bins onto sorting tables where debris, bad grapes and other non-grape material gets picked out. This can be done by human hands or through a variety of other methods as simple as filters (that fit things like grapes but not leaves) or as advanced as optical sorters (sort of like facial recognition software for grapes that only lets the good stuff through). After the sorting table grapes end up in a crusher and destemmer. This is a piece of equipment that looks like a long horizontal washing machine. As the inner drum rotates around, sometimes paddles and sometimes what looks like giant drill bit, gently pluck the grapes from their stems and lightly breaks the skin. From there the grapes go to one of two places.
If a white wine is being made, they go immediately into the press we talked about last time and then onto the fermentation vessel. Since in white wine production winemakers want minimal skin contact, the juice is immediately pressed to minimize skin contact. They still need a little contact with the skins since this is where all the flavor and little bit of color comes from. If a red wine is being made, however, winemakers need longer skin contact in order to get more color and tannin than white wine. For red wine production, winemakers leave the grape juice in contact with the skins, putting the must—grape juice and grape skins—straight into the fermentation tank. This process is called maceration and typically lasts through the entire fermentation process, somewhere between six days and two weeks for most wines.
Winemakers choose from several different types of fermentation vessels. The most common are probably large stainless steel tanks. These are usually fairly large and are helpful to winemakers since they make it easy to control two things essential to a successful fermentation: temperature and cleanliness. Stainless steel is super easy to clean and is usually wrapped with a metal “jacket”, more like a blanket, that water runs through to control the temperature. Winemakers can set the temperature for each tank. Some wineries have even tied their temperature control settings into an online system so that they can change the temperature from anywhere they want. Other fermentation tanks are made of wood or concrete. Wood, as you can imagine, is a bit more traditional but many producers still like using it. Wood can impart some flavor if it’s new, and let’s air into contact with the wine, something some winemakers find beneficial. Concrete has been used for a while, but is becoming a more popular choice because it is a neutral material like stainless steel, meaning it doesn’t impact the flavor of the wine, and it is slightly porous like wood, which allows air to move in and out of the fermenting grape juice.
After the aging is complete the wine is ready to be bottled. It is taken from whatever vessel it’s being aged in and put into a blending tank. From there it gets put into a bottle. It may age a bit longer in bottle or it may be packaged for shipping right away in which case, it is labeled and put into a box.
That’s pretty much it. As I mentioned, there’s a lot of different choices a winemaker can make along the way. All of these decisions impact the final price of that bottle. And pretty much all of them change how the wine that comes out of the bottle tastes.