Winemakers who make red wine ferment their pulp and skins together, in contrast to white wine grapes which are crushed to extract juice. The tannins and colour as well as the flavor of the wine are taken from the skins. To keep the liquid close to the skins winemakers must “punch down” or press on the cap several times a throughout the day.
Fermentation
The winemakers set crushed grapes into tanks that are where the yeast will consume sugars that transform the grapes into alcohol. Red wines are fermented with the skins left on. This adds colour, flavor and texture to the final product. Must is the name given to this particular juice.
During this stage, as the fermentation continues, a layer of solids (called a cap) develops on top of the liquid. The cap will dissolve into the must when you mix the must (known as punching and pumping) is mixing. The juice may absorb aromas and tastes of the skins by contacting the skins.
Some wines are later matured by aging them in large oak vats or oak barrels that are left for several months or even a couple of years. This stage adds additional complexity and richness to the wine, particularly through interaction with the concrete or wood used in the aging. For the ultimate wine, many winemakers blend several barrels and vats. The acidity of red wines is also lowered by the maturation process.
Press to the right
As opposed to white wine, which usually fermented prior to pressing, red wine benefits from having its juice come into close contact with its skins. Maceration is the process that permits flavors, texture, color and substances to be extracted, and yeast transforms sugar into alcohol.
This results in a red wine with more tannins, more flavor, and more color than white wine. For these reasons, most dry red wine spends 18-24 months aging before bottling.
As red wine ages and aging, winemakers must eliminate the sediments that build up in tanks or barrels. Racking is a method that requires siphoning or pumping wine out of the bottom of a barrel or tank to clear unneeded deposits. The winemaker can also alter a cloudy or tannic wine by fining. It is a process that utilizes binding substances such as egg whites and isinglass as well as bentonite clay, to bind to and force out unwanted particles of sediment.
Along with removing unnecessary particles, press can also remove more harsh chemical compounds from the pomace. They also make the final wine easier to drink and smoother. The process is usually a labor intensive, time consuming, but critical component of winemaking.
Blending
The grape skins provide for a large part of the taste and colour of wine that is red, and this is why they need to keep in close contact with the wine. Maceration is a process in which winemakers “punch” or stir to open the cap. It is the clump of grapes that have been crushed up floating above the fermenting wine.
It is important to make sure that the skins and juice can be as full of flavour and tannins as they can. Some winemakers also opt to begin the maceration process ahead of the fermentation process, leaving the grapes rest in tanks for several days to draw additional colour and flavor in the skins.
The art of blending really comes into play, and this is the place where the most exciting wines are made. Traditional red blends like French Bordeaux, GSM wines (Grenache-Syrah-Mourvedre) and Italian chianti are blended to set proportions, which gives them their signature taste. They are more popular than ever before because they’re more costly, as well as they make it easier to market.
Filtration
The process of filtering is the forcing of cloudy wine through small pores for capturing contaminants, such as yeast that has died and bacteria. A pad or a cartridge is the most common filtering medium. This latter option is more common for small wineries. The pore size will be determined by the amount of the cellulose fibers get packed into. The sizes of the pores on rough filters and absolute filter are different. A rough filter has a larger pore, while the absolute filter is smaller.
The sedimentation of grapeskins and yeasts present in red wines can cause a thick layer of dirt at the bottom of tanks. The clarifying agents, such as egg whites or isinglass could be added to wine to help remove these bits.
It is also utilized by winemakers to maintain the stability of microbial life. This is especially important for wines with a higher sugar content, which may be subjected to an uncontrolled fermentation after bottling caused by an aeration yeast that is present in the environment. To achieve this it is first necessary to examine and modify the free sulfite levels to avoid spoilage by bacterial.
Packaging
After the wine has matured and come into balance after which it’s finely separated before being bottled. In most cases, a final sulfur dioxide adjustment is done here. The wine then gets bottled with corks and labels.
The wine should be shielded from oxygen intrusion throughout the aging process. Otherwise, it is susceptible to unpredictable reactions that could cause unpleasant smells or deterioration. To do this, fill the carboys up to the maximum and leave their airlocks ajar. At times, inert gasses like nitrogen and argon are employed for covering the wine in its maturation process.
The wine is then bottled into glass bottles, using natural or synthetic corks. The corks must be sanitized and sterilized in order to stop the development of microorganisms which produce TCA as well as TBA (the smelly “nail polish removal” fragrance). ufanax are generally frozen to prevent the growth of unattractive tartrate crystals inside the bottle. Many wines are also fining made with egg white or gelatin, to help clear and repair flaws such as excess tannin. It is commonly used on wines prone oxidation, like wines with a high alcohol content such as those that drink early.