Maceration is thewinemaking process where thephenolic materials of the grape—tannins, coloring agents (anthocyanins) and flavor compounds—are leached from the grape skins, seeds and stems into themust. To macerate is to soften by soaking, and maceration is the process by which the red wine receives its red color, since raw grape juice (with the exceptions ofteinturiers) is clear-grayish in color. In the production of white wines, maceration is either avoided or allowed only in very limited manner in the form of a short amount of skin contact with the juice prior topressing. This is more common in the production ofvarietals with less natural flavor and body structure likeSauvignon blanc andSémillon. ForRosé, red wine grapes are allowed some maceration between the skins and must, but not to the extent of red wine production.[1]
While maceration is a technique usually associated with wine, it is used with other drinks, such asLambic,piołunówka,Campari andcrème de cassis, and also used to steep unflavored spirit with herbs for making herb-based alcohol likeabsinthe.
The process of maceration begins, to varying extent, as soon as the grapes' skins are broken and exposed to some degree ofheat.Temperature is the guiding force, with higher temperatures encouraging more breakdown and extraction ofphenols from the skins and other grape materials. Maceration continues during thefermentation period, and can last well past the point when theyeast has converted all sugars into alcohol. The process itself is a slow one with compounds such as the anthocyanins needing to pass through thecell membrane of the skins to come into contact with the wine. During fermentation, higher temperatures and higheralcohol levels can encourage this process with the alcohol acting as asolvent to assist in the breakdown of theorganic compounds within the grape materials. This process seems to slow once the wine reaches an alcohol level of 10%.[1]
Throughout the fermentation process,carbon dioxide is released as a byproduct of the conversion of sugar into alcohol. The carbon dioxide seeks to escape from the must by rising to the top of the mixture, pushing the grape skins and other materials to the top as well. This forms what is known as acap that is visible on top of the fermentation vessel. At this point, a very limited amount of the must comes into contact with the skins, and winemakers seek to correct this by pushing down the cap (either with equipment or the traditional method of treading with their feet) or by pumping wine out from under and over onto the cap. This process of "pumping over" or "punching down" the cap is done often throughout the fermentation process, depending on the extent of maceration the winemaker desires.[1] An efficient and modern method of maceration is the "pneumatage process" in which compressed air or gas is sequentially injected into the juice. The bubbles created during the pneumatage process uses gravity and the weight of the juice to circulate the wine juice with the cap of skins and grape solids allowing for greater extraction of aroma, coloring agents and tannins to diffuse into the wine juice ("must").
Depending on the varietal, the process of maceration can help bring out many flavors in the wine that would otherwise be lacking. It can enhance thebody andmouthfeel for many wines, as well as strengthen the color. Greater extraction can add to the complexity and life expectancy of the wine by developing more complex tannins that will soften over a longer period of time. With these benefits does come the risk of developing variouswine faults, such as the development ofacetic (or "volatile") acidity. Too much extraction can also increase the harshness of some tannins to where the wine is not very approachable to most wine drinkers.[1]
One classical method of maceration isgrape treading orpigeage, where grapes are crushed in vats by barefoot workers.
The process ofcold maceration orcold soak is where temperatures of the fermenting must are kept low to encourage extraction by water and addedsulfur dioxide rather than relying principally on heat and alcohol to act as a solvent. This technique was popular in the production ofBurgundy wines in the 1970s and 1980s but there is still some debate amongoenologists about the overall benefits to and resulting quality of the wine.[1]
Carbonic maceration is the fermentation of whole clusters of unbroken grapes in an atmospheresaturated withcarbon dioxide, which prevents traditional yeast fermentation. It is a process different from what is commonly referred to in winemaking as "maceration".
| Harvest | |
|---|---|
| Pressing | |
| Maceration | |
| Fermentation | |
| Aging | |
| Other steps | |
| Related | |
