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Autolysis (wine)
Autolysis in winemaking relates to the complex chemical reactions that take place when a wine spends time in contact with the lees, or dead yeast cells, after fermentation. While for some wines - and all beers - autolysis is undesirable, it is a vital component in shaping the flavors and mouth feel associated with premium Champagne production.J. Robinson (ed) ''"The Oxford Companion to Wine"'' Third Edition pg 54 Oxford University Press 2006 The practice of leaving a wine to age on its lees (or '' sur lie'' aging) has a long history in winemaking dating back to Roman winemaking. The chemical process and details of autolysis were not originally understood scientifically, but the positive effects such as a creamy mouthfeel, breadlike and floral aromas, and reduced astringency were noticed early in the history of wine. Jancis Robinson (ed), ''The Oxford Companion to Wine'' Third Edition pg 399 Oxford University Press 2006 History Ancient Roman writers, such as Marcus Porciu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocktail By Candle Light 1
A cocktail is an alcoholic mixed drink. Most commonly, cocktails are either a combination of spirits, or one or more spirits mixed with other ingredients such as tonic water, fruit juice, flavored syrup, or cream. Cocktails vary widely across regions of the world, and many websites publish both original recipes and their own interpretations of older and more famous cocktails. History The origins of the word ''cocktail'' have been debated (see section Etymology). The first written mention of ''cocktail'' as a beverage appeared in ''The Farmers Cabinet,'' 1803 in the United States. The first definition of a cocktail as an alcoholic beverage appeared three years later in ''The Balance and Columbian Repository'' (Hudson, New York) May 13, 1806. Traditionally, cocktail ingredients included spirits, sugar, water and bitters, however, this definition evolved throughout the 1800s, to include the addition of a liqueur. In 1862 Jerry Thomas published a bartenders: guide called ''How ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appellation D'origine Contrôlée
An appellation is a legally defined and protected geographical indication primarily used to identify where the grapes for a wine were grown, although other types of food often have appellations as well. Restrictions other than geographical boundaries, such as what grapes may be grown, maximum grape yields, alcohol level, and other quality factors may also apply before an appellation name may legally appear on a wine bottle label. The rules that govern appellations are dependent on the country in which the wine was produced. History The tradition of wine appellation is very old. The oldest references are to be found in the Bible, where ''wine of Samaria'', ''wine of Carmel'', ''wine of Jezreel'', or ''wine of Helbon'' are mentioned. This tradition of appellation continued throughout the Antiquity and the Middle Ages, though without any officially sanctioned rules. Historically, the world's first exclusive (protected) vineyard zone was introduced in Chianti, Italy in 1716 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycoproteins
Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. Secreted extracellular proteins are often glycosylated. In proteins that have segments extending extracellularly, the extracellular segments are also often glycosylated. Glycoproteins are also often important integral membrane proteins, where they play a role in cell–cell interactions. It is important to distinguish endoplasmic reticulum-based glycosylation of the secretory system from reversible cytosolic-nuclear glycosylation. Glycoproteins of the cytosol and nucleus can be modified through the reversible addition of a single GlcNAc residue that is considered reciprocal to phosphorylation and the functions of these are likely to be an additional regulatory mechanism that controls phosphorylation-based signalling. In contrast, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mannose
Mannose is a sugar monomer of the aldohexose series of carbohydrates. It is a C-2 epimer of glucose. Mannose is important in human metabolism, especially in the glycosylation of certain proteins. Several congenital disorders of glycosylation are associated with mutations in enzymes involved in mannose metabolism. Mannose is not an essential nutrient; it can be produced in the human body from glucose, or converted into glucose. Mannose provides 2–5 kcal/g. It is partially excreted in the urine. Etymology The root of both "mannose" and "mannitol" is manna, which the Bible describes as the food supplied to the Israelites during their journey in the region of Sinai. Several trees and shrubs can produce a substance called manna, such as the "manna tree" ('' Fraxinus ornus'') from whose secretions mannitol was originally isolated. Structure Mannose commonly exists as two different-sized rings, the pyranose (six-membered) form and the furanose (five-membered) form. E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzymes
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Racking
Racking, often referred to as Soutirage or Soutirage traditionnel (meaning racking in French), also filtering or fining, is the process of moving wine or beer from one container to another using gravity rather than a pump, which can be disruptive to the beverage. The process is also known as ''Abstich'' in German and ''travaso'' in Italian. ''Alexis Lichine's Encyclopedia of Wines and Spirits'' defines racking as "siphoning wine or beer off the lees (in the case of wine) or trub (in the case of beer), into a new, clean barrel or other vessel". Racking allows clarification and aids in stabilization. Wine that is allowed to age on the lees often develops "off-tastes". A racking hose or tube is used and can be attached to a racking cane to make the task easier. The racking process is repeated several times during the aging of wine. Process Racking or soutirage is a traditional method in wine production of moving wine from one barrel to another using gravity rather than a pump ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxic
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell ( cytotoxicity) or an organ such as the liver (hepatotoxicity). By extension, the word may be metaphorically used to describe toxic effects on larger and more complex groups, such as the family unit or society at large. Sometimes the word is more or less synonymous with poisoning in everyday usage. A central concept of toxicology is that the effects of a toxicant are dose-dependent; even water can lead to water intoxication when taken in too high a dose, whereas for even a very toxic substance such as snake venom there is a dose below which there is no detectable toxic effect. Toxicity is species-specific, making cross-species analysis problematic. Newer paradigms and metrics are evolving to byp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yeast Assimilable Nitrogen
Yeast assimilable nitrogen or YAN is the combination of free amino nitrogen (FAN), ammonia (NH3) and ammonium (NH4+) that is available for a yeast, e.g. the wine yeast ''Saccharomyces cerevisiae'', to use during fermentation. Outside of the fermentable sugars glucose and fructose, nitrogen is the most important nutrient needed to carry out a successful fermentation that doesn't end prior to the intended point of dryness or sees the development of off-odors and related wine faults. To this extent winemakers will often supplement the available YAN resources with nitrogen additives such as diammonium phosphate (DAP).B. Zoecklein, K. Fugelsang, B. Gump, F. Nury ''Wine Analysis and Production'' pgs 152-163, 340-343, 444-445, 467 Kluwer Academic Publishers, New York (1999) However, the addition of excessive amounts of nitrogen can also create a hazard as other organisms besides beneficial wine yeast can utilize the nutrients. These include spoilage organisms such as ''Brettanomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a hydroxyl group). Ethanol is a volatile, flammable, colorless liquid with a characteristic wine-like odor and pungent taste. It is a psychoactive recreational drug, the active ingredient in alcoholic drinks. Ethanol is naturally produced by the fermentation process of sugars by yeasts or via petrochemical processes such as ethylene hydration. It has medical applications as an antiseptic and disinfectant. It is used as a chemical solvent and in the synthesis of organic compounds, and as a fuel source. Ethanol also can be dehydrated to make ethylene, an important chemical feedstock. As of 2006, world production of ethanol was , coming mostly from Brazil and the U.S. Etymology ''Ethanol'' is the systematic name defined by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the total weight of the must. Making must is the first step in winemaking. Because of its high glucose content, typically between 10 and 15%, must is also used as a sweetener in a variety of cuisines. Unlike commercially sold grape juice, which is filtered and pasteurized, must is thick with particulate matter, opaque, and comes in various shades of brown and purple. Winemaking The length of time the pomace stays in the juice is critical for the final character of the wine. When the winemaker judges the time to be right, the juice is drained off the pomace, which is then pressed to extract the juice retained by the matrix. Yeast is added to the juice to begin the fermentation, while the pomace is often returned to the vineyard or orchard for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sugar (wine)
Sugars in wine are at the heart of what makes winemaking possible. During the process of fermentation, sugars from wine grapes are broken down and converted by yeast into alcohol (ethanol) and carbon dioxide. Grapes accumulate sugars as they grow on the grapevine through the translocation of sucrose molecules that are produced by photosynthesis from the leaves. During ripening the sucrose molecules are hydrolyzed (separated) by the enzyme invertase into glucose and fructose. By the time of harvest, between 15 and 25% of the grape will be composed of simple sugars. Both glucose and fructose are six-carbon sugars but three-, four-, five- and seven-carbon sugars are also present in the grape. Not all sugars are fermentable, with sugars like the five-carbon arabinose, rhamnose and xylose still being present in the wine after fermentation. Very high sugar content will effectively kill the yeast once a certain (high) alcohol content is reached. For these reasons, no wine is ever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
