A winepress is a device used to extract juice from crushed grapes during winemaking. There are a number of different styles of presses that are used by wine makers but their overall functionality is the same. Each style of press exerts controlled pressure in order to free the juice from the fruit (most often grapes). The pressure must be controlled, especially with grapes, in order to avoid crushing the seeds and releasing a great deal of undesirable tannins into the wine. [1] Wine was being made at least as long ago as 4000 BC; in 2011, a winepress was unearthed in Armenia with red wine dated 6,000 years old. [2]
A basket press consists of a large basket filled with the crushed grapes. Pressure is applied through a plate that is forced down onto the fruit. The mechanism to lower the plate is often either a screw or a hydraulic device. The juice flows through openings in the basket. The basket style press was the first type of mechanized press to be developed, and its basic design has not changed in nearly 1000 years. [3]
A horizontal screw press works using the same principle as the basket press. Instead of a plate being brought down to put pressure on the grapes, plates from either side of a closed cylinder are brought together to squeeze the grapes. Generally the volume of grapes handled is significantly greater than that of a basket press. [4]
A bladder press consists of a large cylinder, closed at each end, into which the fruit is loaded. To press the grapes, a large bladder expands and pushes the grapes against the sides. The juice then flows out through small openings in the cylinder. The cylinder rotates during the process to help homogenize the pressure that is placed on the grapes. [5]
A continuous screw press differs from the above presses in that it does not process a single batch of grapes at a time. Instead it uses an Archimedes' screw to continuously force grapes up against the wall of the device. Juice is extracted, and the pomace continues through to the end where it is extracted. [6] This style of press is rarely used to produce table wines, and some countries forbid its use for higher quality wines. [7]
Flash release is a technique used in winepressing. [8] The treatment consists of heating the grapes with steam almost to boiling and then submitting them to a strong vacuum. The technique allows for a better extraction of phenolic compounds. [9]
A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus Vitis. Grapes are a non-climacteric type of fruit, generally occurring in clusters.
A fruit press is a device used to separate fruit solids—stems, skins, seeds, pulp, leaves, and detritus—from fruit juice.
Winemaking, wine-making, 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. There is evidence that suggests that the earliest wine production took place in Georgia and Iran around 6000 to 5000 B.C. The science of wine and winemaking is known as oenology. A winemaker may also be called a vintner. The growing of grapes is viticulture and there are many varieties of grapes.
Fruit wines are fermented alcoholic beverages made from a variety of base ingredients ; they may also have additional flavors taken from fruits, flowers, and herbs. This definition is sometimes broadened to include any alcoholic fermented beverage except beer. For historical reasons, mead, cider, and perry are also excluded from the definition of fruit wine.
Pomace, or marc, is the solid remains of grapes, olives, or other fruit after pressing for juice or oil. It contains the skins, pulp, seeds, and stems of the fruit.
Red wine is a type of wine made from dark-colored grape varieties. The color of the wine can range from intense violet, typical of young wines, through to brick red for mature wines and brown for older red wines. The juice from most purple grapes is greenish-white, the red color coming from anthocyan pigments present in the skin of the grape. Much of the red wine production process involves extraction of color and flavor components from the grape skin.
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. The pink color can range from a pale "onionskin" orange to a vivid near-purple, depending on the grape varieties used and winemaking techniques. Usually, the wine is labelled rosé in French, Portuguese, and English-speaking countries, rosado in Spanish, or rosato in Italian.
Maceration is the winemaking process where the phenolic materials of the grape—tannins, coloring agents (anthocyanins) and flavor compounds—are leached from the grape skins, seeds and stems into the must. 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 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 varietals with less natural flavor and body structure like Sauvignon blanc and Sémillon. For Rosé, red wine grapes are allowed some maceration between the skins and must, but not to the extent of red wine production.
Olive oil extraction is the process of extracting the olive oil present in olive drupes. Olive oil is produced in the mesocarp cells, and stored in a particular type of vacuole called a lipo vacuole, i.e., every cell contains a tiny olive oil droplet. Olive oil extraction is the process of separating the oil from the other fruit contents. It is possible to attain this separation by physical means alone, i.e., oil and water do not mix, so they are relatively easy to separate. This contrasts with other oils that are extracted with chemical solvents, generally hexane. The first operation when extracting olive oil is washing the olives, to reduce the presence of contaminants, especially soil which can create a particular flavor effect called "soil taste".
Grape juice is obtained from crushing and blending grapes into a liquid. In the wine industry, grape juice that contains 7–23 percent of pulp, skins, stems and seeds is often referred to as must. The sugars in grape juice allow it to be used as a sweetener, and fermented and made into wine, brandy, or vinegar.
The following outline is provided as an overview of and topical guide to wine:
This glossary of winemaking terms lists some of terms and definitions involved in making wine, fruit wine, and mead.
In winemaking, pressing is the process where juice is extracted from the grapes with the aid of a wine-press, by hand, or even by the weight of the grape berries and clusters. Historically, intact grape clusters were trodden by feet but in most wineries today the grapes are sent through a crusher/destemmer, which removes the individual grape berries from the stems and breaks the skins, releasing some juice, prior to being pressed. There are exceptions, such as the case of sparkling wine production in regions such as Champagne where grapes are traditionally whole-cluster pressed with stems included to produce a lighter must that is low in phenolics.
In winemaking, clarification and stabilization are the processes by which insoluble matter suspended in the wine is removed before bottling. This matter may include dead yeast cells (lees), bacteria, tartrates, proteins, pectins, various tannins and other phenolic compounds, as well as pieces of grape skin, pulp, stems and gums. Clarification and stabilization may involve fining, filtration, centrifugation, flotation, refrigeration, pasteurization, and/or barrel maturation and racking.
A cider mill, also known as a cidery, is the location and equipment used to crush apples into apple juice for use in making apple cider, hard cider, applejack, apple wine, pectin and other products derived from apples. More specifically, it refers to a device used to crush or grind apples as part of the overall juice production.
An oil mill is a grinding mill designed to crush or bruise oil-bearing seeds, such as linseed or peanuts, or other oil-rich vegetable material, such as olives or the fruit of the oil palm, which can then be pressed to extract vegetable oils, which may be used as foods or for cooking, as oleochemical feedstocks, as lubricants, or as biofuels. The pomace or press cake – the remaining solid material from which the oil has been extracted – may also be used as a food or fertilizer.
Flash release (FR) is a technique used in wine pressing. The technique allows for a better extraction of phenolic compounds and wine polysaccharides.
The history of the wine press and of pressing is nearly as old as the history of wine itself with the remains of wine presses providing some of the longest-serving evidence of organised viticulture and winemaking in the ancient world. The earliest wine press was probably the human foot or hand, crushing and squeezing grapes into a bag or container where the contents would ferment.
Grape-treading or grape-stomping is part of the method of maceration used in traditional wine-making. Rather than being crushed in a wine press or by another mechanized method, grapes are repeatedly trampled in vats by barefoot participants to release their juices and begin fermentation. Grape-treading was widespread in the history of winemaking, but with the introduction of industrial methods, it now survives mostly as a recreational or competitive activity at cultural festivals.
Christ in the winepress or the mystical winepress is a motif in Christian iconography showing Christ standing in a winepress, where Christ himself becomes the grapes in the press. It derives from the interpretation by Augustine and other early theologians of a group of passages in the Bible and is found as a visual image in Christian art between about 1100 and the 18th century, as well as in religious literature of many kinds. The image in art underwent a number of changes of emphasis, while remaining fairly consistent in its basic visual content, and was one of the relatively few medieval metaphorical or allegorical devotional images to maintain a foothold in Protestant iconography after the Reformation.