![Raisin noir à jus blanc](https://upload.wikimedia.org/wikipedia/commons/e/e5/Raisin_noir_%C3%A0_jus_blanc.png)
Maceration is the
winemaking
Winemaking or vinification is the production of wine, starting with the selection of the fruit, its fermentation into alcohol, and the bottling of the finished liquid. The history of wine-making stretches over millennia. The science of wine and ...
process where the
phenolic
Phenolic is an adjective and a substantive (noun) that may apply to :
* Phenol (or carbolic acid), a colorless crystalline solid and aromatic compound
* Phenols, a class of chemical compounds that include phenol
* Phenolic content in wine
* Phenol ...
materials of the grape—
tannins
Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids.
The term ''tannin'' (from Anglo-Norman ''tanner'', f ...
, coloring agents (
anthocyanins
Anthocyanins (), also called anthocyans, are water-soluble vacuolar pigments that, depending on their pH, may appear red, purple, blue, or black. In 1835, the German pharmacist Ludwig Clamor Marquart gave the name Anthokyan to a chemical compo ...
) and flavor compounds—are leached from the grape skins, seeds and stems into the
must
Must (from the Latin ''vinum mustum'', "young wine") is freshly crushed fruit juice (usually grape juice) that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace and typically makes up 7–23% of t ...
. 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 of
teinturier
Teinturier grapes are grapes whose flesh and juice is red in colour due to anthocyanin pigments accumulating within the pulp of the grape berry itself. In most cases, anthocyanin pigments are confined to the outer skin tissue only, and the squee ...
s) 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 to
pressing. This is more common in the production of
varietal
A varietal wine is a wine made primarily from a single named grape variety, and which typically displays the name of that variety on the wine label.The American Heritage Dictionary of the English Language, Fourth Edition, 2000.winepros.com.au. ...
s with less natural flavor and body structure like
Sauvignon blanc
is a green-skinned grape variety that originates from the Bordeaux region of France. The grape most likely gets its name from the French words ''sauvage'' ("wild") and ''blanc'' ("white") due to its early origins as an indigenous grape in ...
and
Sémillon
Sémillon is a golden-skinned grape used to make dry and sweet white wines, mostly in France and Australia. Its thin skin and susceptibility to botrytis make it dominate the sweet wine region Sauternes AOC and Barsac AOC.
History
The Sémill ...
. For
Rosé
A rosé () is a type of wine that incorporates some of the color from the grape skins, but not enough to qualify it as a red wine. It may be the oldest known type of wine, as it is the most straightforward to make with the skin contact method. ...
, red wine grapes are allowed some maceration between the skins and must, but not to the extent of red wine production.
While maceration is a technique usually associated with wine, it is used with other drinks, such as
Lambic
Lambic () is a type of beer brewed in the Pajottenland region of Belgium southwest of Brussels and in Brussels itself since the 13th century. Types of lambic beers include gueuze, kriek lambic and framboise. Lambic differs from most other beers ...
,
piołunówka
Piołunówka () is a very bitter alcoholic infusion (Polish: "nalewka") made by Maceration (wine), macerating Artemisia (plant), wormwood in alcohol. Its name comes from ''piołun'', which means ''wormwood'' in Polish language, Polish. It is becom ...
,
Campari
Campari () is an Italian alcoholic liqueur, considered an apéritif (20.5%, 21%, 24%, 25%, or 28.5% ABV, depending on the country where it is sold), obtained from the infusion of herbs and fruit (including chinotto and cascarilla) in alcohol and ...
and
crème de cassis
Crème de cassis () (also known as Cassis liqueur) is a sweet, dark red liqueur made from blackcurrants.
Several cocktails are made with crème de cassis, including the popular wine cocktail, kir.
It may also be served as an after-dinner li ...
, and also used to steep unflavored spirit with herbs for making herb-based alcohol like
absinthe
Absinthe (, ) is an anise-flavoured spirit derived from several plants, including the flowers and leaves of ''Artemisia absinthium'' ("grand wormwood"), together with green anise, sweet fennel, and other medicinal and culinary herbs. Historical ...
.
Process
![Red wine cap](https://upload.wikimedia.org/wikipedia/commons/e/e1/Red_wine_cap.jpg)
The process of maceration begins, to varying extent, as soon as the grapes' skins are broken and exposed to some degree of
heat
In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is al ...
.
Temperature
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer.
Thermometers are calibrated in various temperature scales that historically have relied o ...
is the guiding force, with higher temperatures encouraging more breakdown and extraction of
phenols
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (— O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds are c ...
from the skins and other grape materials. Maceration continues during the
fermentation
Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen. In food ...
period, and can last well past the point when the
yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitut ...
has converted all sugars into alcohol. The process itself is a slow one with compounds such as the anthocyanins needing to pass through the
cell membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...
of the skins to come into contact with the wine. During fermentation, higher temperatures and higher
alcohol
Alcohol most commonly refers to:
* Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom
* Alcohol (drug), an intoxicant found in alcoholic drinks
Alcohol may also refer to:
Chemicals
* Ethanol, one of sev ...
levels can encourage this process with the alcohol acting as a
solvent
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...
to assist in the breakdown of the
organic compounds
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The s ...
within the grape materials. This process seems to slow once the wine reaches an alcohol level of 10%.
Throughout the fermentation process,
carbon dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...
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 a ''cap'' 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.
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").
Benefits
![Teinturier Agria and peeled Grenache grape](https://upload.wikimedia.org/wikipedia/commons/5/50/Teinturier_Agria_and_peeled_Grenache_grape.png)
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 the
body
Body may refer to:
In science
* Physical body, an object in physics that represents a large amount, has mass or takes up space
* Body (biology), the physical material of an organism
* Body plan, the physical features shared by a group of anima ...
and
mouthfeel
Mouthfeel refers to the physical sensations in the mouth caused by food or drink, making it distinct from taste. It is a fundamental sensory attribute which, along with taste and smell, determines the overall flavor of a food item. Mouthfeel is ...
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 various
wine fault
A wine fault or defect is an unpleasant characteristic of a wine often resulting from poor winemaking practices or storage conditions, and leading to wine spoilage. Many of the compounds that cause wine faults are already naturally present in wine ...
s, such as the development of
acetic (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.
Other processes
One classical method of maceration is
grape treading
Grape-treading or grape-stomping is part of the method of maceration used in traditional wine-making.Clarke, Oz (2009). ''Oz Clarke's Pocket Wine Guide 2010.'' Sterling Publishing Company, Cheap, BA (2010). ''Mr. Cheap's Guide to Wine.'' Adams Me ...
or ''pigeage'', where grapes are crushed in vats by barefoot workers.
The process of cold maceration or
cold soak
Cold is the presence of low temperature, especially in the atmosphere. In common usage, cold is often a subjective perception. A lower bound to temperature is absolute zero, defined as 0.00K on the Kelvin scale, an absolute thermodynamic ...
is where temperatures of the fermenting must are kept low to encourage extraction by water and added
sulfur dioxide
Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic activ ...
rather than relying principally on heat and alcohol to act as a solvent. This technique was popular in the production of
Burgundy wine
Burgundy wine ( or ') is made in the Burgundy region of eastern France, in the valleys and slopes west of the Saône, a tributary of the Rhône. The most famous wines produced here, and those commonly referred to as "Burgundies," are dry red wi ...
s in the 1970s and 1980s but there is still some debate among
oenologist
Oenology (also enology; ) is the science and study of wine and winemaking. Oenology is distinct from viticulture, which is the science of the growing, cultivation, and harvesting of grapes. The English word oenology derives from the Greek word ' ...
s about the overall benefits to and resulting quality of the wine.
Carbonic maceration
Carbonic maceration is a winemaking technique, often associated with the French wine region of Beaujolais, in which whole grapes are fermented in a carbon dioxide rich environment before crushing. Conventional alcoholic fermentation involves crush ...
is the fermentation of whole clusters of unbroken grapes in an atmosphere
saturated
Saturation, saturated, unsaturation or unsaturated may refer to:
Chemistry
* Saturation, a property of organic compounds referring to carbon-carbon bonds
** Saturated and unsaturated compounds
**Degree of unsaturation
** Saturated fat or fatty ac ...
with
carbon dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...
, which prevents traditional yeast fermentation. It is a process different from what is commonly referred to in winemaking as "maceration".
References
{{Winemaking
Winemaking
Wine terminology
de:Mazeration
fr:Macération