In “Wine Basics – What is Wine”, we covered the elements of fermentation. These “Vine to Wine” posts will go through the steps involved in turning grapes into wine. Please note, there are a lot of variations on each step. This makes it necessary to keep the information here general. As is often the case with wine, exceptions can be found for most of the things I say.
As I was writing this I found it to be way too long for one post so I have divided it into three parts. This first part will cover from after the picking of the grapes until the grapes are pressed. The second will look at how the wine maker deals with fermentation. The last section will cover aging the wine in the winery cellar and bottling the wine.
After grapes are picked they are they are brought to the winery. The first step is to sort them, removing bad bunches such as rotten or under ripe ones. How rigorous this process is can have a lot to do with how the wine will taste. Some wineries reject any grapes they don’t deem perfect. Others have more relaxed standards. For some wineries only the best grapes go into any wine. Many will divert sub-par grapes for lesser wines or wines destined to be distilled into brandy.
Once the sorting is done, the grapes are removed from their stems. Here there is a fair amount of variation and it has more to do with style than quality. Almost all white wines and roses are thoroughly de-stemmed.
With red wines, the winery may decide to allow some stems to stay in the process.
One reason to do so is stems contain tannins which are beneficial in red wine. If the grapes are deficient in tannins, keeping some stems can increase the tannin level. Some wine makers leave some stems as a matter of course. That is traditional in some areas such as Chateau Nuef Du Pape. A winemaker may choose to never use stems and others do it on a case by case basis.
There can be a downside to keeping some stems. In addition to the possibility of having too much tannin, stems can add flavors that are described as herbal or like green peppers. Many people don’t like these flavors in red wine.
The next step is usually crushing the grapes. There is an exception called semi-carbonic maceration but we will get to that some other time. Grapes are crushed using any of a number of systems and presses. In a very few areas they still crush by stamping the grapes with their feet, but that is rare. Pressing is a bit trickier than you would think. Almost all grapes used in making wine have seeds. The seeds have some bitter and otherwise unpleasant flavors in them. The trick is to press the grapes enough to get as much juice as possible without crushing too many seeds.
What comes next depends on the kind of wine being made. With white wines the juice is separated from the skin as quickly as possible. With reds they are left together. For more information see “Wine Basics – Why is Red Wine Red, White Wine White, and What is Rose Anyway?”
In Part 2 we will cover from juice to wine.