Red wine is the most common type of red wine. Many people like to use the term “red wine” to refer to all red wines. As the name implies, red wine is only one of many red wines. Freshly squeezed grape juice is not dark in color and is lighter in color than pink wine. The red color comes mainly from the skins of the grapes, so only red/black grapes can be used to make red wine.
Red wine making methods.
There are two ways to pick grapes: by machine or by hand. Only hand-picked grapes have stems. The stems contain a lot of tannins and a very “raw” vanilla flavor. Before making red wine, the stems are usually removed and the grapes are pressed to extract the juice.
The pressing is also very subtle – avoid pressing the seeds, which contain a lot of tannins and bitter oils. If you are careless with red wine, the wine will become bitter. Therefore, in ancient times, it was common for people to stomp on the grape seeds with their feet, without ever crushing them on the bottom of the footplate. At this time, the pressed grape juice was called “gravity juice”.
2、Soaking
As mentioned above, the color of red wine comes from the grape skins. The pressed juice must be macerated in the skins to release color, tannins and aromas. Some winemakers cold macerate – soak the skins at a low temperature to release color and “special” aromas (below 5°C to inhibit fermentation) – before fermentation. More color is released mainly in the early stages of fermentation, and more tannins are released in the later stages of fermentation as the temperature and alcohol content of the red wine increases.
3、Fermentation
Under the action of yeast, the sugar in the must is slowly converted into alcohol and carbon dioxide, while releasing heat and aromatic compounds. Fermentation does not stop until the sugar is completely converted or the yeast stops. Sulfur dioxide and alcohol levels of about 16% and temperatures between 35 and 38°C will kill the yeast. This is often referred to as “dry red”, meaning that the sugar in the must is completely converted during fermentation, producing a red wine with little or no sugar remaining. Alcoholic fermentation usually lasts 1~3 weeks.
4、Change the tank
After fermentation, the red wine should be separated from the lees. However, the leather residue is not directly discarded. The winemaker will also press the leather residue to obtain a “pressed red wine”. The pressed red wine is darker in color and has higher tannins than the artesian red wine. The winemaker will mix the pressed red wine and the artesian red wine according to the style of red wine he wants to make.
5. Lactic Fermentation
After alcohol fermentation, lactic acid fermentation takes place under the action of lactic acid bacteria. The pungent fruit acids are transformed into soft lactic acid, which means that the red wine gradually becomes sour and produces aromas similar to butter and hazelnut. All red wines are fermented by lactic acid. After alcoholic fermentation, lactic fermentation occurs naturally by raising the temperature of the red wine without adding sulfur dioxide.
At this point, the wine is matured in red wine tanks or oak barrels for a period of time ranging from 4 months to 4 years, and the aromas are further developed and changed. During this process, the winemaker may add egg whites to precipitate suspended solids and clarify the wine. Before bottling, the winemaker may choose to filter the residue or not to filter it to make the wine fuller. Before serving, it is advisable to allow the wine to decant without separating the residue.
