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 100000 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.
Icewine is a type of dessert wine produced from grapes that have been frozen while still on the vine. The sugars and other dissolved solids do not freeze, but the water does, allowing for a more concentrated grape juice to develop. The grapes' must is then pressed from the frozen grapes, resulting in a smaller amount of more concentrated, very sweet juice. With icewines, the freezing happens before the fermentation, not afterwards. Unlike the grapes from which other dessert wines are made, such as Sauternes, Tokaji, or Trockenbeerenauslese, icewine grapes should not be affected by Botrytis cinerea or noble rot, at least not to any great degree. Only healthy grapes keep in good shape until the opportunity arises for an icewine harvest, which in extreme cases can occur after the New Year, on a northern hemisphere calendar. This gives icewine its characteristic refreshing sweetness balanced by high acidity. When the grapes are free of Botrytis, they are said to come in "clean". This results in a very complex and sweet wine. Much icewine is made from the grapes Riesling, Vidal, Cabernet Franc and Cabernet Sauvignon, but there is also icewine made from Shiraz, Merlot, Sangiovese and others.
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.
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.
The role of yeast in winemaking is the most important element that distinguishes wine from fruit juice. In the absence of oxygen, yeast converts the sugars of the fruit into alcohol and carbon dioxide through the process of fermentation. The more sugars in the grapes, the higher the potential alcohol level of the wine if the yeast are allowed to carry out fermentation to dryness. Sometimes winemakers will stop fermentation early in order to leave some residual sugars and sweetness in the wine such as with dessert wines. This can be achieved by dropping fermentation temperatures to the point where the yeast are inactive, sterile filtering the wine to remove the yeast or fortification with brandy or neutral spirits to kill off the yeast cells. If fermentation is unintentionally stopped, such as when the yeasts become exhausted of available nutrients and the wine has not yet reached dryness, this is considered a stuck fermentation.
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.