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100-698: Weingut Gunderloch is a German wine grower and producer based in Nackenheim in the Rheinhessen wine region . The Gunderloch estate was created by a banker hailing from Mainz in 1890 during the German Gründerzeit . Carl Gunderloch, originating from Gundersheim , acquired the Dalheimer Hof from the secularised property of the Cistercian abbey of Dalheim near Mainz, as well as some outstanding vineyards like

200-439: A secondary fermentation . Fermentation may be done in stainless steel tanks, which is common with many white wines like Riesling , in an open wooden vat, inside a wine barrel and inside the wine bottle itself as in the production of many sparkling wines . The natural occurrence of fermentation means it was probably first observed long ago by humans. The earliest uses of the word "fermentation" in relation to winemaking

300-416: A by-product ). In winemaking , the temperature and speed of fermentation are important considerations as well as the levels of oxygen present in the must at the start of the fermentation. The risk of stuck fermentation and the development of several wine faults can also occur during this stage, which can last anywhere from 5 to 14 days for primary fermentation and potentially another 5 to 10 days for

400-449: A laboratory to check the status of the wine. Common tests include Brix , pH , titratable acidity , residual sugar , free or available sulfur , total sulfur, volatile acidity (V.A.) and percent alcohol. Additional tests include those for the crystallization of cream of tartar ( potassium hydrogen tartrate ) and the precipitation of heat unstable protein ; this last test is limited to white wines. These tests may be performed throughout

500-468: A 2.5–5% error, which is sufficient to control the level of sulphur dioxide in wine. Different batches of wine can be mixed before bottling in order to achieve the desired taste. The winemaker can correct perceived inadequacies by mixing wines from different grapes and batches that were produced under different conditions. These adjustments can be as simple as adjusting acid or tannin levels, to as complex as blending different varieties or vintages to achieve

600-587: A cheaper alternative. In the French Baumé (Be° or Bé° for short) one Be° corresponds approximately to one percent alcohol. One Be° is equal to 1.8 °Bx, that is 1.8 grams of sugar per one hundred grams. Therefore, to achieve one percent alcohol the winemaker adds sugar at a rate of 1.8 grams per 100 ml (18 grams per liter) – a practice known as chaptalization , which is illegal in some countries and in California. Volatile acidity test verifies if there

700-413: A consistent taste. Fining agents are used during winemaking to remove tannins , reduce astringency and remove microscopic particles that could cloud the wines. The winemakers decide on which fining agents are used and these may vary from product to product and even batch to batch (usually depending on the grapes of that particular year). Gelatin [gelatine] has been used in winemaking for centuries and

800-404: A cylinder of wooden slats on top of a fixed plate, with a moveable plate that can be forced downward (usually by a central ratcheting threaded screw). The press operator would load the grapes or pomace into the wooden cylinder, put the top plate in place and lower it until juice flowed from the wooden slats. As the juice flow decreased, the plate was ratcheted down again. This process continued until

900-426: A dried or "inactive" state and is reactivated in warm water or diluted grape juice prior to being added to the must . To thrive and be active in fermentation, the yeast needs access to a continuous supply of carbon , nitrogen , sulfur , phosphorus as well as access to various vitamins and minerals . These components are naturally present in the grape must but their amount may be corrected by adding nutrients to

1000-691: A fundamental role in malolactic fermentation which is essentially the conversion of malic acid into lactic acid . This has the benefit of reducing some of the tartness and making the resulting wine taste softer. Depending on the style of wine that the winemaker is trying to produce, malolactic fermentation may take place at the very same time as the yeast fermentation. Alternatively, some strains of yeast may be developed that can convert L-malate to L-lactate during alcohol fermentation. For example, Saccharomyces cerevisiae strain ML01 ( S. cerevisiae strain ML01), which carries

1100-435: A lot or tank of wine. Destemming is the process of separating stems from the grapes. Depending on the winemaking procedure, this process may be undertaken before crushing with the purpose of lowering the development of tannins and vegetal flavors in the resulting wine. Single berry harvesting, as is done with some German Trockenbeerenauslese , avoids this step altogether with the grapes being individually selected. Crushing

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1200-410: A movable surface and slowly decrease the volume between the two surfaces. Modern presses dictate the duration and pressure at each press cycle, usually ramping from 0 Bar to 2.0 Bar. Sometimes winemakers choose pressures which separate the streams of pressed juice, called making "press cuts." As the pressure increases the amount of tannin extracted from the skins into the juice increases, often rendering

1300-425: A number of additives are included, such as acids, amino acids, sugars, and organic compounds. The quality of the grapes determines the quality of the wine more than any other factor. Grape quality is affected by variety as well as weather during the growing season, soil minerals and acidity, time of harvest, and pruning method. The combination of these effects is often referred to as the grape's terroir . Given

1400-406: A rate of 0.1 units per 1 gram/litre of tartaric acid addition. The use of lactic acid bacteria is the reason why some chardonnays can taste "buttery" due to the production of diacetyl by the bacteria. Most red wines go through complete malolactic fermentation, both to lessen the acid of the wine and to remove the possibility that malolactic fermentation will occur in the bottle. White wines vary in

1500-434: A secondary fermentation where sugar and additional yeast known as liqueur de tirage is added to the wine. This secondary fermentation is what creates the carbon dioxide bubbles that sparkling wine is known for. The process of carbonic maceration is also known as whole grape fermentation where instead of yeast being added, the grapes fermentation is encouraged to take place inside the individual grape berries. This method

1600-542: A series of a reaction that convert sugar into alcohol. The discovery of the Embden–Meyerhof–Parnas pathway by Gustav Embden , Otto Fritz Meyerhof and Jakub Karol Parnas in the early 20th century contributed more to the understanding of the complex chemical processes involved in the conversion of sugar to alcohol. In the early 2010s, New Jersey based wine tech company GOfermentor invented an automated winemaking device that ferments in single-use liners similar to

1700-438: A wine is reverse osmosis. Blending may also help – a wine with high V.A. can be filtered (to remove the microbe responsible) and blended with a low V.A. wine, so that the acetic acid level is below the sensory threshold. Sulphur dioxide can be readily measured with relatively simple laboratory equipment. There are several methods available; a typical test involves acidification of a sample with phosphoric acid, distillation of

1800-433: Is Vitis vinifera , which includes nearly all varieties of European origin. Harvest is the picking of the grapes and in many ways the first step in wine production. Grapes are either harvested mechanically or by hand. The decision to harvest grapes is typically made by the winemaker and informed by the level of sugar (called °Brix ), acid (TA or Titratable Acidity as expressed by tartaric acid equivalents) and pH of

1900-423: Is sulfur dioxide (SO 2 ), normally added in one of the following forms: liquid sulfur dioxide, sodium or potassium metabisulphite . Another useful preservative is potassium sorbate . Fermentation (wine) The process of fermentation in winemaking turns grape juice into an alcoholic beverage. During fermentation , yeasts transform sugars present in the juice into ethanol and carbon dioxide (as

2000-402: Is Riesling with 80%. 6% burgundy and 5% Silvaner are notable as well. The remaining percentages split in specialties. An average yield of 55 hl/ha is achieved. Winemaking Winemaking can be divided into two general categories: still wine production (without carbonation) and sparkling wine production (with carbonation – natural or injected). Red wine , white wine , and rosé are

2100-410: Is a French term for the management of acidity and secondary pressing of grapes in fermentation tanks. To make certain types of wine, grapes are put through a crusher and then poured into open fermentation tanks. Once fermentation begins, the grape skins are floated to the surface by carbon dioxide gases released in the fermentation process. This layer of skins and other solids is known as the cap. As

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2200-490: Is a by-product of microbial metabolism. Because acetic acid bacteria require oxygen to grow, eliminating any air in wine containers as well as addition of sulfur dioxide (SO 2 ) will limit their growth. Rejecting moldy grapes also prevents possible problems associated with acetic acid bacteria. Use of sulfur dioxide and inoculation with a low-V.A. producing strain of Saccharomyces may deter acetic acid producing yeast. A relatively new method for removal of volatile acidity from

2300-419: Is any steam distillable acids in the wine. Mainly present is acetic acid (the dominant component of vinegar ), but lactic , butyric , propionic , and formic acid can also be found. Usually the test checks for these acids in a cash still, but there are other methods available such as HPLC, gas chromatography and enzymatic methods. The amount of volatile acidity found in sound grapes is negligible, because it

2400-451: Is calculated from the measured density, the must weight , with the help of a specialized type of hydrometer called a saccharometer . If the sugar content of the grapes is too low to obtain the desired alcohol percentage, sugar can be added ( chaptalization ). In commercial winemaking, chaptalization is subject to local regulations. Similar to chaptalization is amelioration. While chaptalization aims to raise final alcohol percentage through

2500-442: Is carried out either as an intentional procedure in which specially cultivated strains of such bacteria are introduced into the maturing wine, or it can happen by chance if uncultivated lactic acid bacteria are present. Malolactic fermentation can improve the taste of wine that has high levels of malic acid, because malic acid, in higher concentration, generally causes an unpleasant harsh and bitter taste sensation, whereas lactic acid

2600-482: Is common in the creation of Beaujolais wine and involves whole clusters of grapes being stored in a closed container with the oxygen in the container being replaced with carbon dioxide. Unlike normal fermentation where yeast converts sugar into alcohol, carbonic maceration works by enzymes within the grape breaking down the cellular matter to form ethanol and other chemical properties. The resulting wines are typically soft and fruity. Instead of yeast, bacteria play

2700-399: Is fermented between 18–20 °C (64–68 °F) though a wine maker may choose to use a higher temperature to bring out some of the complexity of the wine. Red wine is typically fermented at higher temperatures 20–30 °C (68–86 °F). Fermentation at higher temperatures may have adverse effect on the wine in stunning the yeast to inactivity and even "boiling off" some of the flavors of

2800-404: Is known as the bulk Charmat method . Other sparkling wines, such as prosecco , are fermented using force-carbonation — a faster process that involves using machinery to manually add CO 2 and create bubbles. Sweet wines or off-dry wines are made by arresting fermentation before all sugar has been converted into ethanol and allowing some residual sugar to remain. This can be done by chilling

2900-518: Is mainly used in cheaper wine. Amateur winemakers often use glass carboys in the production of their wine; these vessels (sometimes called demijohns ) have a capacity of 4.5–54 litres (0.99–11.88 imp gal; 1.2–14.3 US gal). The kind of vessel used depends on the amount of wine that is being made, the grapes being used, and the intentions of the winemaker. Malolactic fermentation occurs when lactic acid bacteria metabolize malic acid and produce lactic acid and carbon dioxide. This

3000-402: Is measured in grams per hundred grams of solution, so 20 °Bx means that 100 grams of juice contains 20 g of dissolved compounds. There are other common measures of sugar content of grapes, specific gravity , Oechsle (Germany) and Baumé (France). °Bx is usually measured with a refractometer while the other methods use a hydrometer which measures specific gravity. Generally, hydrometers are

3100-682: Is milk protein), egg whites , egg albumin , bone char , bull 's blood, isinglass (Sturgeon bladder), PVPP (a synthetic compound), lysozyme , and skim milk powder . Although not common, finely ground eggshell is also sometimes used. Some aromatized wines contain honey or egg-yolk extract , or other woody extractives by artificial aging with small chips. Non- animal-based filtering agents are also often used, such as bentonite (a volcanic clay-based filter), diatomaceous earth , cellulose pads, paper filters and membrane filters (thin films of plastic polymer material having uniformly sized holes). The most common preservative used in winemaking

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3200-414: Is more acceptable if the stems have 'ripened' and started to turn brown. If increased skin extraction is desired, a winemaker might choose to crush the grapes after destemming. Removal of stems first means no stem tannin can be extracted. In these cases the grapes pass between two rollers which squeeze the grapes enough to separate the skin and pulp, but not so much as to cause excessive shearing or tearing of

3300-410: Is more gentle and less sour. Lactic acid is an acid found in dairy products. Malolactic fermentation usually results in a reduction in the amount of total acidity of the wine. This is because malic acid has two acid radicals (-COOH) while lactic acid has only one. However, the pH should be monitored and not allowed to rise above a pH of 3.55 for whites or a pH of 3.80 for reds. pH can be reduced roughly at

3400-399: Is not always a necessary act in winemaking; if grapes are crushed there is a considerable amount of juice immediately liberated (called free-run juice) that can be used for vinification. Typically this free-run juice is of a higher quality than the press juice. Pressed juice is typically lesser in quality due to the release and increase of total phenolic compounds, as well as browning index and

3500-518: Is now cellar master at that estate in Kamptal, Austrial. Johannes Hasselbach became the winemaker at Gunderloch upon the death of his father Fritz in 2016. The name of the estate owner Gunderloch had become known since 1925 by the comedy The Merry Vineyard  [ de ] written by Carl Zuckmayer . The fashion of the comedy did not amuse Gunderloch and all the other Nackenheim wine producers, because they had been described as petty bourgeois. In

3600-452: Is recognized as a traditional method for wine fining, or clarifying . It is also the most commonly used agent to reduce the tannin content. Generally no gelatin remains in the wine because it reacts with the wine components, as it clarifies, and forms a sediment which is removed by filtration prior to bottling. Besides gelatin, other fining agents for wine are often derived from animal products, such as micronized potassium caseinate ( casein

3700-418: Is separated from the must before fermentation . With rose, the skins may be kept in contact for a shorter period to give color to the wine, in that case the must may be pressed as well. After a period in which the wine stands or ages, the wine is separated from the dead yeast and any solids that remained (called lees ), and transferred to a new container where any additional fermentation may take place. Pigeage

3800-421: Is the development of chemical residue and spoilage which can be corrected with the addition of sulfur dioxide (SO 2 ), although excess SO 2 can lead to a wine fault. A winemaker who wishes to make a wine with high levels of residual sugar (like a dessert wine ) may stop fermentation early either by dropping the temperature of the must to stun the yeast or by adding a high level of alcohol (like brandy ) to

3900-428: Is the failure for the fermentation to go to completion, that is some sugar remains unfermented. This can make the wine sweet when a dry wine is desired. Frequently wild ferments lead to the production of unpleasant acetic acid (vinegar) production as a by product. During the primary fermentation, the yeast cells feed on the sugars in the must and multiply, producing carbon dioxide gas and alcohol . The temperature during

4000-518: Is the hand-picking of grape clusters from the grapevines . In the United States, some grapes are picked into one- or two-ton bins for transport back to the winery. Manual harvesting has the advantage of using knowledgeable labor to not only pick the ripe clusters but also to leave behind the clusters that are not ripe or contain bunch rot or other defects. This can be an effective first line of defense to prevent inferior quality fruit from contaminating

4100-413: Is the process when gently squeezing the berries and breaking the skins to start to liberate the contents of the berries. Destemming is the process of removing the grapes from the rachis (the stem which holds the grapes). In traditional and smaller-scale wine making, the harvested grapes are sometimes crushed by trampling them barefoot or by the use of inexpensive small scale crushers. These can also destem at

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4200-559: The Saccharomyces cerevisiae (also known as "sugar yeast") species. Within this species are several hundred different strains of yeast that can be used during fermentation to affect the heat or vigor of the process and enhance or suppress certain flavor characteristics of the varietal . The use of different strains of yeasts is a major contributor to the diversity of wine, even among the same grape variety. Alternative, non- Saccharomyces cerevisiae , yeasts are being used more prevalently in

4300-477: The free run wine is pumped off into tanks and the skins are pressed to extract the remaining juice and wine. The press wine is blended with the free run wine at the winemaker's discretion. The wine is then kept warm and the remaining sugars are converted into alcohol and carbon dioxide. The next process in the making of red wine is malolactic conversion , a bacterial process which converts "crisp, green apple" malic acid to "soft, creamy" lactic acid , softening

4400-631: The single-use bioreactor . In winemaking, there are distinctions made between ambient yeasts which are naturally present in wine cellars, vineyards and on the grapes themselves (sometimes known as a grape's "bloom" or "blush") and cultured yeast which are specifically isolated and inoculated for use in winemaking. The most common genera of wild yeasts found in winemaking include Candida , Klöckera/Hanseniaspora , Metschnikowiaceae , Pichia and Zygosaccharomyces . Wild yeasts can produce high-quality, unique-flavored wines; however, they are often unpredictable and may introduce less desirable traits to

4500-452: The C6-alcohol levels. These compounds are responsible for the herb-like taste perceived in wine with pressed grapes. However, most wineries do use presses in order to increase their production (gallons) per ton, as pressed juice can represent between 15%-30% of the total juice volume from the grape. Presses act by positioning the grape skins or whole grape clusters between a rigid surface and

4600-462: The absence of air. In winemaking, there are different processes that fall under the title of "Fermentation" but might not follow the same procedure commonly associated with wine fermentation. Bottle fermentation is a method of sparkling wine production , originating in the Champagne region where after the cuvee has gone through a primary yeast fermentation the wine is then bottled and goes through

4700-434: The acetaldehyde to be eventually converted, by reduction, to ethanol . During the conversion of acetaldehyde, a small amount is converted, by oxidation, to acetic acid which, in excess, can contribute to the wine fault known as volatile acidity (vinegar taint). After the yeast has exhausted its life cycle, they fall to the bottom of the fermentation tank as sediment known as lees . Yeast ceases its activity whenever all of

4800-576: The addition of sugar, amelioration aims to raise the alcohol percentage and dilute the acidity levels through the addition of water and sugar into the grape must. This wine adjustment was commonly used in New York State's cooler wine regions, such as the Finger Lakes AVA . Amelioration is also subject to federal regulations. Alcohol of more than 12% can be achieved by using yeast that can withstand high alcohol. Some yeasts can produce 18% alcohol in

4900-536: The advantage of being able to cover a large area of vineyard land in a relatively short period of time, and with a minimum investment of manpower per harvested ton. A disadvantage of mechanical harvesting is the indiscriminate inclusion of foreign non-grape material in the product, especially leaf stems and leaves, but also, depending on the trellis system and grapevine canopy management, may include moldy grapes, canes, metal debris, rocks and even small animals and bird nests. Some winemakers remove leaves and loose debris from

5000-407: The appearance of (harmless) tartrate crystals after bottling. The result of these processes is that the originally cloudy wine becomes clear. The wine can be racked during this process to remove the lees . The secondary fermentation usually takes place in large stainless steel vessels with a volume of several cubic meters, oak barrels or glass demijohns (also referred to as carboys), depending on

5100-662: The course of the 1970s the Geisenheimer Fritz Hasselbach saw the importance of the international printed wine media as a marketing instrument for estates and their top vineyards. In 1979 Agnes and Fritz Hasselbach decided to invest in their winery and to quit their jobs as a teacher in a private school and in the former Landeslehr- und Versuchsanstalt für Wein- und Gartenbau (“federal experimental station for viticulture and horticulture”) in Oppenheim , today: Dienstleistungszentrum Ländlicher Raum  [ de ] . During

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5200-471: The dark Malvidin 3,5-diglucoside anthocyanin ) and therefore contact between the juice and skins is essential for color extraction. Red wines are produced by destemming and crushing the grapes into a tank and leaving the skins in contact with the juice throughout the fermentation ( maceration ). It is possible to produce white (colorless) wines from red grapes by the fastidious pressing of uncrushed fruit. This minimizes contact between grape juice and skins (as in

5300-451: The dark skins long enough to pick up a pinkish color (maceration or saignée), or (less commonly) by blending red wine with white wine. White and rosé wines extract little of the grape tannins contained in the skins. Orange wine (a.k.a. skin-contact white wine) is wine made with maceration in the manner of rosé or red wine production, but using white wine grape varieties instead of red. To start primary fermentation, yeast may be added to

5400-501: The effect during fermentation of releasing glycoside hydrolase which can hydrolyse the flavor precursors of aliphatics (a flavor component that reacts with oak ), benzene derivatives, monoterpenes (responsible for floral aromas from grapes like Muscat and Traminer ), norisoprenoids (responsible for some of the spice notes in Chardonnay ), and phenols . Some strains of yeasts can generate volatile thiols which contribute to

5500-404: The fermentation affects both the taste of the end product, as well as the speed of the fermentation. For red wines, the temperature is typically 22 to 25 °C, and for white wines 15 to 18 °C. For every gram of sugar that is converted, about half a gram of alcohol is produced, so to achieve a 12% alcohol concentration, the must should contain about 24% sugars. The sugar percentage of the must

5600-446: The fruity aromas in many wines such as the gooseberry scent commonly associated with Sauvignon blanc . Brettanomyces yeasts are responsible for the "barnyard aroma" characteristic in some red wines like Burgundy and Pinot noir . Methanol is not a major constituent of wine. The usual concentration range is between 0.1 g/liter and 0.2 g/liter. These small traces have no adverse effect on people and no direct effect on

5700-430: The goals of the winemakers. Unoaked wine is fermented in a barrel made of stainless steel or other material having no influence on the final taste of the wine. Depending on the desired taste, it could be fermented mainly in stainless steel to be briefly put in oak, or have the complete fermentation done in stainless steel. Oak could be added as chips used with a non-wooden barrel instead of a fully wooden barrel. This process

5800-451: The grapes to raisin either on the vine or on racks or straw mats. Often in these high sugar wines, the fermentation stops naturally as the high concentration of sugar and rising concentration of ethanol retard the yeast activity. Similarly in fortified wines, such as port wine , high proof neutral grape spirit ( brandy ) is added to arrest the ferment and adjust the alcohol content when the desired sugar level has been reached. In other cases,

5900-433: The grapes. Other considerations include phenological ripeness, berry flavor, tannin development (seed color and taste). Overall disposition of the grapevine and weather forecasts are taken into account. Mechanical harvesters are large tractors that straddle grapevine trellises and, using firm plastic or rubber rods, strike the fruiting zone of the grapevine to dislodge the grapes from the rachis . Mechanical harvesters have

6000-440: The grapevine before mechanical harvesting to avoid such material being included in the harvested fruit. In the United States mechanical harvesting is seldom used for premium winemaking because of the indiscriminate picking and increased oxidation of the grape juice. In other countries (such as Australia and New Zealand), mechanical harvesting of premium winegrapes is more common because of general labor shortages. Manual harvesting

6100-408: The industry to add greater complexity to wine. After a winery has been in operation for a number of years, few yeast strains are actively involved in the fermentation process. The use of active dry yeasts reduces the variety of strains that appear in spontaneous fermentation by outcompeting those strains that are naturally present. The addition of cultured yeast normally occurs with the yeast first in

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6200-429: The introduction of active yeasts to the grape must, phosphates are attached to the sugar and the six-carbon sugar molecules begin to be split into three-carbon pieces and go through a series of rearrangement reactions . During this process, the carboxylic carbon atom is released in the form of carbon dioxide with the remaining components becoming acetaldehyde . The absence of oxygen in this anaerobic process allows

6300-407: The juice to travel before leaving the press. It is believed by advocates of basket presses that this relatively long pathway through the grape or pomace cake serves as a filter to solids that would otherwise affect the quality of the press juice. With red wines, the must is pressed after primary fermentation, which separates the skins and other solid matter from the liquid. With white wine, the liquid

6400-416: The juice, this method is sometimes referred to as pre-fermentation maceration as it extracts tannins and pigment from the skins. As a result this is applicable to red grape varieties that would otherwise undergo traditional maceration. Most white wines are processed without destemming or crushing and are transferred from picking bins directly to the press. This is to avoid any extraction of tannin from either

6500-483: The liberated SO 2 , and capture by hydrogen peroxide solution. The SO 2 and peroxide react to form sulphuric acid, which is then titrated with NaOH to an end point with an indicator, and the volume of NaOH required is used to calculate the SO 2 level. This method has inaccuracies associated with red wine, inefficient condensers, and excessive aspiration rate, although the results are reproducible, having an accuracy with just

6600-419: The making of Blanc de noirs sparkling wine, which is derived from Pinot noir, a red vinifera grape). An alternative method to maceration is hot press or thermovinification. In this practice, winemakers heat up the grapes to extract the juice rather than pressing using a pressure method. The temperature and time ranges depending on the grape variety and preferences of the winemaker. In addition to extracting

6700-402: The making of the wine as well as prior to bottling. In response to the results of these tests, a winemaker can decide on appropriate remedial action, for example the addition of more sulfur dioxide. Sensory tests will also be performed and again in response to these a winemaker may take remedial action such as the addition of a protein to soften the taste of the wine. Brix (°Bx) is one measure of

6800-403: The must for red wine, or may occur naturally as ambient yeast on the grapes (or in the air). For white wine, yeast may be added to the juice. During this fermentation, which often takes between one and two weeks, the yeast converts most of the sugars in the grape juice into ethanol (alcohol) and carbon dioxide (which is lost to the atmosphere). After the primary fermentation of red grapes,

6900-410: The must to kill off the yeast and create a fortified wine . The ethanol produced through fermentation acts as an important co-solvent to the non-polar compound that water cannot dissolve, such as pigments from grape skins, giving wine varieties their distinct color, and other aromatics. Ethanol and the acidity of wine act as an inhibitor to bacterial growth, allowing wine to be safely kept for years in

7000-467: The other main categories. Although most wine is made from grapes , it may also be made from other plants. (See fruit wine .) Other similar light alcoholic drinks (as opposed to beer or spirits ) include mead , made by fermenting honey and water, cider ("apple cider"), made by fermenting the juice of apples , and perry ("pear cider"), made by fermenting the juice of pears , and kumis , made of fermented mare's milk. There are five basic stages to

7100-441: The pH of the juice which may be desirable for overly acidic grapes. This was a practice more common in the 1970s than today, though still practiced by some Sauvignon blanc and Chardonnay producers in California. In the case of rosé wines, the fruit is crushed and the dark skins are left in contact with the juice just long enough to extract the color that the winemaker desires. The must is then pressed, and fermentation continues as if

7200-417: The press operator determined that the quality of the pressed juice or wine was below standard, or all liquids had been pressed. Since the early 1990s, modern mechanical basket presses have been revived through higher-end producers seeking to replicate the gentle pressing of the historical basket presses. Because basket presses have a relatively compact design, the press cake offers a relatively longer pathway for

7300-440: The press. For red winemaking, stems of the grapes are usually removed before fermentation since the stems have a relatively high tannin content; in addition to tannin they can also give the wine a vegetal aroma (due to extraction of 3-isobutyl-2-methoxypyrazine which has an aroma reminiscent of green bell peppers ). On occasion, the winemaker may decide to leave them in if the grapes themselves contain less tannin than desired. This

7400-490: The pressed juice excessively tannic or harsh. Because of the location of grape juice constituents in the berry (water and acid are found primarily in the mesocarp or pulp, whereas tannins are found primarily in the exocarp , or skin , and seeds ), pressed juice or wine tends to be lower in acidity with a higher pH than the free-run juice. Before the advent of modern winemaking, most presses were basket presses made of wood and operated manually. Basket presses are composed of

7500-410: The quality of grape and the target wine style, some of these steps may be combined or omitted to achieve the particular goals of the winemaker. Many wines of comparable quality are produced using similar but distinctly different approaches to their production. Variations on the above procedure exist. With sparkling wines such as Champagne and Methodé Champenoise (sparkling wine that is fermented in

7600-408: The same time. However, in larger wineries, a mechanical crusher/destemmer is used. The decision about destemming is different for red and white wine making. Generally when making white wine the fruit is only crushed, the stems are then placed in the press with the berries. The presence of stems in the mix facilitates pressing by allowing juice to flow past flattened skins. These accumulate at the edge of

7700-441: The secondary fermentation and aging process , which takes three to six months, the fermentation continues very slowly. The wine is kept under an airlock to protect the wine from oxidation. Proteins from the grape are broken down and the remaining yeast cells and other fine particles from the grapes are allowed to settle. Potassium bitartrate will also precipitate, a process which can be enhanced by cold stabilization to prevent

7800-416: The senses. During fermentation, there are several factors that winemakers take into consideration, with the most influential to ethanol production being sugar content in the must, the yeast strain used, and the fermentation temperature. The biochemical process of fermentation itself creates a lot of residual heat which can take the must out of the ideal temperature range for the wine. Typically, white wine

7900-466: The sensitivity of grapes to weather patterns, winemaking is affected by climate change . Grapes are usually harvested from the vineyard from early September until early November in the northern hemisphere, and mid February until early March in the southern hemisphere. In some cool areas in the southern hemisphere (such as in Tasmania), harvesting extends into May. The most common species of wine grape

8000-411: The skin tissues. In some cases, notably with "delicate" red varietals such as Pinot noir or Syrah , all or part of the grapes might be left uncrushed (called "whole berry") to encourage the retention of fruity aromas through partial carbonic maceration . Most red wines derive their color from grape skins (the exception being varieties or hybrids of non-vinifera vines which contain juice pigmented with

8100-430: The skins are the source of the tannins , the cap needs to be mixed through the liquid each day, or "punched", which traditionally is done by stomping through the vat. Cold stabilization is a process used in winemaking to reduce tartrate crystals (generally potassium bitartrate ) in wine. These tartrate crystals look like grains of clear sand, and are also known as "wine crystals" or "wine diamonds". They are formed by

8200-545: The skins or grapeseeds, as well as maintaining proper juice flow through a matrix of grape clusters rather than loose berries. In some circumstances winemakers choose to crush white grapes for a short period of skin contact, usually for three to 24 hours. This serves to extract flavor and tannin from the skins (the tannin being extracted to encourage protein precipitation without excessive Bentonite addition) as well as potassium ions, which participate in bitartrate precipitation ( cream of tartar ). It also results in an increase in

8300-443: The soluble solids in the grape juice and represents not only the sugars but also includes many other soluble substances such as salts, acids and tannins, sometimes called total dissolved solids (TDS). Because sugar is the dominant compound in grape juice, these units are effectively a measure of sugar level. The level of sugar in the grapes determines the final alcohol content of the wine as well as indirect index of grape maturity. °Bx

8400-462: The style of champagne but is not from the Champagne region of France), an additional, "secondary" fermentation takes place inside the bottle, dissolving trapped carbon dioxide in the wine and creating the characteristic bubbles. Bottles then spend 6 months on a riddling rack before being disgorged to remove any sediment that has accrued. An expedited technique using sealed tanks to contain carbon dioxide

8500-654: The sugar in must has been converted into other chemicals or whenever the alcohol content has reached 15% alcohol per unit volume; a concentration strong enough to halt the enzymatic activity of almost all strains of yeast. The metabolism of amino acids and breakdown of sugars by yeasts has the effect of creating other biochemical compounds that can contribute to the flavor and aroma of wine . These compounds can be considered " volatile " like aldehydes , ethyl acetate , ester , fatty acids , fusel oils , hydrogen sulfide , ketones and mercaptans or "non-volatile" like glycerol , acetic acid and succinic acid . Yeast also has

8600-636: The taste of the wine. Red wine is characteristically transferred to white oak barrels to mature for a period of weeks or months; this practice imparts oak aromas and some oak tannins to the wine. The wine must be settled or clarified and adjustments made prior to bottling. The time from harvest to drinking can vary from a few months for Beaujolais nouveau wines (made by carbonic maceration ) to over twenty years for wine of good structure with high levels of acid, tannin or sugar. However, only about 10% of all red and 5% of white wine will taste better after five years than it will after just one year. Depending on

8700-507: The union of tartaric acid and potassium, and may appear to be [sediment] in the wine, though they are not. During the cold stabilizing process after fermentation, the temperature of the wine is dropped to close to freezing for 1–2 weeks. This will cause the crystals to separate from the wine and stick to the sides of the holding vessel. When the wine is drained from the vessels, the tartrates are left behind. They may also form in wine bottles that have been stored under very cold conditions. During

8800-434: The use of malolactic fermentation during their making. Lighter aromatic wines such as Riesling, generally do not go through malolactic fermentation. The fuller white wines, such as barrel-fermented chardonnay, are more commonly put through malolactic fermentation. Sometimes a partial fermentation, for example, somewhere less than 50% might be employed. Whether the wine is aging in tanks or barrels, tests are run periodically in

8900-408: The wine and adding sulphur and other allowable additives to inhibit yeast activity, or sterile filtering the wine to remove all yeast and bacteria. In the case of sweet wines, initial sugar concentrations are increased by harvesting late ( late harvest wine ), freezing the grapes to concentrate the sugar ( ice wine ), allowing or encouraging Botrytis cinerea fungus to dehydrate the grapes or allowing

9000-502: The wine however extra sugar is added to produce a high alcohol content. During or after the alcoholic fermentation, a secondary, or malolactic fermentation can also take place, during which specific strains of bacteria (lactobacter) convert malic acid into the milder lactic acid . This fermentation is often initiated by inoculation with desired bacteria. Pressing is the act of applying pressure to grapes or pomace in order to separate juice or wine from grapes and grape skins. Pressing

9100-401: The wine making process which begins with harvesting or picking. After the harvest, the grapes are taken into a winery and prepared for primary ferment ; at this stage red wine making diverges from white wine making. Red wine is made from the must (pulp, including the juice) of red or black grapes and fermentation occurs together with the grape skins, which impart color, flavor and tannins to

9200-429: The wine through the process of maceration . White wine is made by fermenting juice which is made by pressing crushed grapes to extract a juice; the skins are removed and play no further role. Occasionally, white wine is made from red grapes. This is done by extracting their juice with minimal contact with the grapes' skins. Rosé wines are either made from red grapes where the juice is allowed to stay in contact with

9300-483: The wine, and can even contribute to spoilage. Few yeast, and lactic and acetic acid bacterial colonies naturally live on the surface of grapes, but traditional wine makers, particularly in Europe, advocate use of ambient yeast as a characteristic of the region's terroir ; nevertheless, many winemakers prefer to control fermentation with predictable cultured yeast. The cultured yeasts most commonly used in winemaking belong to

9400-409: The wine, in order to foster a more encouraging environment for the yeast. Newly formulated time-release nutrients, specifically manufactured for wine fermentations, offer the most advantageous conditions for yeast. Oxygen is needed as well, but in wine making, the risk of oxidation and the lack of alcohol production from oxygenated yeast requires the exposure of oxygen to be kept at a minimum. Upon

9500-490: The winemaker may choose to hold back some of the sweet grape juice and add it to the wine after the fermentation is done, a technique known in Germany as süssreserve . The process produces wastewater , pomace , and lees that require collection, treatment, and disposal or beneficial use. Synthetic wines (also known as engineered wines or fake wines ) are a product that do not use grapes at all. Starting with water and ethanol,

9600-420: The winemaker was making a white wine. Yeast is normally already present on the grapes, often visible as a powdery appearance of the grapes. The primary, or alcoholic fermentation can be done with this natural yeast, but since this can give unpredictable results depending on the exact types of yeast that are present, cultured yeast is often added to the must. One of the main problems with the use of wild ferments

9700-545: The wines. Some winemakers may ferment their red wines at cooler temperatures, more typical of white wines, in order to bring out more fruit flavors. To control the heat generated during fermentation, the winemaker must choose a suitable vessel size or else use a cooling device. Various kinds of cooling devices are available, ranging from the ancient Bordeaux practice of placing the fermentation vat atop blocks of ice to sophisticated fermentation tanks that have built-in cooling rings. иьИс A risk factor involved with fermentation

9800-794: The years, important networks to leading wine critics like Stuart Pigott were established and maintained. Johannes Hasselbach took over the responsibility for the estate. He is heading the Rheinhessen regional association of the VDP since December 2019. Regine Usinger, (born 1958), married Usinger-Frank, was German wine queen during 1980/1981. The estate is exporting its wine to 34 countries. Gunderloch works with 14 hectares vineyards, including vines in Niersteiner Pettental and Hipping . These are selected sites, capable to produce ″ Grosses Gewächs ″, top-level dry wines. The leading grape variety cultivated

9900-601: The “Nackenheimer Rothenberg” in the “Roter Hang” (Red slope). Following his capital investment he became a protagonist of a new quality oriented viticulture on the Rhinefront . After his death, his winery was divided between his two daughters. The current owner is Agnes Hasselbach-Usinger, the fifth generation in the winery. There are three children of the sixth generation: Stefanie married the Austrian winemaker Alwin Jurtschitsch and

10000-400: Was in reference to the apparent "boiling" within the must that came from the anaerobic reaction of the yeast to the sugars in the grape juice and the release of carbon dioxide. The Latin fervere means, literally, to boil . In the mid-19th century, Louis Pasteur noted the connection between yeast and the process of the fermentation in which the yeast act as catalyst and mediator through

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