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Acids In Wine
The acids in wine are an important component in both winemaking and the finished product of wine. They are present in both grapes and wine, having direct influences on the color, balance and taste of the wine as well as the growth and vitality of yeast during fermentation and protecting the wine from bacteria. The measure of the amount of acidity in wine is known as the “ titratable acidity” or “total acidity”, which refers to the test that yields the total of all acids present, while strength of acidity is measured according to pH, with most wines having a pH between 2.9 and 3.9. Generally, the lower the pH, the higher the acidity in the wine. There is no direct connection between total acidity and pH (it is possible to find wines with a high pH for wine and high acidity). In wine tasting, the term “acidity” refers to the fresh, tart and sour attributes of the wine which are evaluated in relation to how well the acidity balances out the sweetness and bitter component ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wine Grape Diagram En
Wine is an alcoholic drink made from fermented fruit. Yeast consumes the sugar in the fruit and converts it to ethanol and carbon dioxide, releasing heat in the process. Wine is most often made from grapes, and the term "wine" generally refers to grape wine when used without any qualification. Even so, wine can be made from a variety of fruit crops, including plum, cherry, pomegranate, blueberry, currant, and elderberry. Different varieties of grapes and strains of yeasts are major factors in different styles of wine. These differences result from the complex interactions between the biochemical development of the grape, the reactions involved in fermentation, the grape's growing environment (terroir), and the wine production process. Many countries enact legal appellations intended to define styles and qualities of wine. These typically restrict the geographical origin and permitted varieties of grapes, as well as other aspects of wine production. Wine has been produced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Succinic Acid
Succinic acid () is a dicarboxylic acid with the chemical formula (CH2)2(CO2H)2. In living organisms, succinic acid takes the form of an anion, succinate, which has multiple biological roles as a metabolic intermediate being converted into fumarate by the enzyme succinate dehydrogenase in complex 2 of the electron transport chain which is involved in making ATP, and as a signaling molecule reflecting the cellular metabolic state. Succinate is generated in mitochondria via the tricarboxylic acid (TCA) cycle. Succinate can exit the mitochondrial matrix and function in the cytoplasm as well as the extracellular space, changing gene expression patterns, modulating epigenetic landscape or demonstrating hormone-like signaling. As such, succinate links cellular metabolism, especially ATP formation, to the regulation of cellular function. Dysregulation of succinate synthesis, and therefore ATP synthesis, happens in some genetic mitochondrial diseases, such as Leigh syndrome, and Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grape Variety
This list of grape varieties includes cultivated grapes, whether used for wine, or eating as a table grape, fresh or dried (raisin, Zante currant, currant, sultana (grape), sultana). For a complete list of all grape species, including those unimportant to agriculture, see ''Vitis''. The term ''grape variety'' refers to cultivars (rather than the Variety (botany), botanical varieties that must be named according to the International Code of Nomenclature for algae, fungi, and plants). Single-species grapes While some of the grapes in this list are hybrids, they are hybridized within a single species. For those grapes hybridized across species, known as interspecific hybrids, see the section on #Multispecies hybrid grapes, multispecies hybrid grapes below. ''Vitis vinifera'' (wine) Red grapes White grapes Rose grapes ''Vitis vinifera'' (table) Red table grapes * Black Corinth * Black Monukka * Black Rose (grape), Black Rose * Cardinal (grape), Cardinal * Mazza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grape Vine
''Vitis'' (grapevine) is a genus of 81 accepted species of vining plants in the flowering plant family Vitaceae. The genus consists of species predominantly from the Northern Hemisphere. It is economically important as the source of grapes, both for direct consumption of the fruit and for fermentation to produce wine. The study and cultivation of grapevines is called viticulture. Most cultivated ''Vitis'' varieties are wind-pollinated with hermaphroditic flowers containing both male and female reproductive structures, while wild species are dioecious. These flowers are grouped in bunches called inflorescences. In many species, such as ''Vitis vinifera'', each successfully pollinated flower becomes a grape berry with the inflorescence turning into a cluster of grapes. While the flowers of the grapevines are usually very small, the berries are often large and brightly colored with sweet flavors that attract birds and other animals to disperse the seeds contained within the berri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Acid
An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are relatively stronger acids. Alcohols, with –OH, can act as acids but they are usually very weak. The relative stability of the conjugate base of the acid determines its acidity. Other groups can also confer acidity, usually weakly: the thiol group –SH, the enol group, and the phenol group. In biological systems, organic compounds containing these groups are generally referred to as organic acids. A few common examples include: * Lactic acid * Acetic acid * Formic acid * Citric acid * Oxalic acid * Uric acid * Malic acid * Tartaric acid * Butyric acid * Folic acid Characteristics In general, organic acids are weak acids and do not dissociate completely in water, whereas the strong mineral acids do. Lower molecular mass organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stability (wine)
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.J. Robinson (ed) ''"The Oxford Companion to Wine"'' Third Edition, pp. 173, 661–62. Oxford University Press 2006 . Clarification and stabilization may involve fining, filtration, centrifugation, flotation, refrigeration, pasteurization, and/or barrel maturation and racking. Clarifying wine In wine tasting, a wine is considered " clear" when there are no visible particles suspended in the liquid and, especially in the case of white wines, when there is some degree of transparency. A wine with too much suspended matter will appear cloudy and dull, even if its aroma and flavor are unaffected; wines therefore generally undergo some kind of clarificatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfurous Acid
Sulfuric(IV) acid (United Kingdom spelling: sulphuric(IV) acid), also known as sulfurous (UK: sulphurous) acid and thionic acid, is the chemical compound with the chemical formula, formula . Raman spectroscopy, Raman spectra of solutions of sulfur dioxide in water show only signals due to the molecule and the bisulfite ion, . The intensities of the signals are consistent with the following chemical equilibrium, equilibrium: 17O NMR spectroscopy provided evidence that solutions of sulfurous acid and protonated sulfites contain a mixture of isomers, which is in equilibrium: Attempts to concentrate the solutions of sulfurous acid simply reverse the equilibrium, producing sulfur dioxide and water vapor. A clathrate with the formula has been crystallised. It decomposes above 7 °C. History and production Sulfurous acid is commonly known not to exist in its free state, and owing to this, it is stated in textbooks that it cannot be isolated in the water-free form. Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorbic Acid
Sorbic acid, or 2,4-hexadienoic acid, is a natural organic compound used as a food preservative. It has the chemical formula and the structure . It is a colourless solid that is slightly soluble in water and sublimes readily. It was first isolated from the unripe berries of the ''Sorbus aucuparia'' ( rowan tree), hence its name. Production The traditional route to sorbic acid involves condensation of malonic acid and crotonaldehyde. It can also be prepared from isomeric hexadienoic acids, which are available via a nickel-catalyzed reaction of allyl chloride, acetylene, and carbon monoxide. The route used commercially, however, is from crotonaldehyde and ketene. An estimated 30,000 tons are produced annually. History Sorbic acid was isolated in 1859 by distillation of rowanberry oil by A. W. von Hofmann. This affords parasorbic acid, the lactone of sorbic acid, which he converted to sorbic acid by hydrolysis. Its antimicrobial activities were discovered in the late 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascorbic Acid
Ascorbic acid is an organic compound with formula , originally called hexuronic acid. It is a white solid, but impure samples can appear yellowish. It dissolves freely in water to give mildly acidic solutions. It is a mild reducing agent. Ascorbic acid exists as two enantiomers (mirror-image isomers), commonly denoted "" (for "levo") and "" (for "dextro"). The isomer is the one most often encountered: it occurs naturally in many foods, and is one form (" vitamer") of vitamin C, an essential nutrient for humans and many animals. Deficiency of vitamin C causes scurvy, formerly a major disease of sailors in long sea voyages. It is used as a food additive and a dietary supplement for its antioxidant properties. The "" form ( erythorbic acid) can be made by chemical synthesis, but has no significant biological role. Etymology The term ''ascorbic'' means antiscruvy and denotes the ability to fight off scurvy. It is related to combating Vitamin C deficiency. History The antiscor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volatile Acidity
Volatility or volatile may refer to: Chemistry * Volatility (chemistry), a measuring tendency of a substance or liquid to vaporize easily ** Volatile organic compounds, organic or carbon compounds that can evaporate at normal temperature and pressure *** Volatile anaesthetics, a class of anaesthetics which evaporate or vaporize easily *** Volatile substance abuse, the abuse of household inhalants containing volatile compounds *** Volatile oil, also known as essential oil, an oil derived from plants with aromatic compounds used in cosmetic and flavoring industries * Relative volatility, a measure of vapor pressures of the components in a liquid mixture * Volatile acid/Volatile acidity, a term used inconsisitenly across the fields of winemaking, wastewater treatment, physiology, and other fields * Volatile (astrogeology), a group of compounds with low boiling points that are associated with a planet's or moon's crust and atmosphere Computer science * Volatile variables, var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wine Fault
A wine fault is a sensory-associated (organoleptic) characteristic of a wine that is unpleasant, and may include elements of taste, smell, or appearance, elements that may arise from a "chemical or a microbial origin", where particular sensory experiences (e.g., an off-odor) might arise from more than one wine fault. Wine faults may result from poor winemaking practices or storage conditions (wine), storage conditions that lead to ''wine spoilage''. In the case of a chemical origin, many compounds causing wine faults are already naturally present in wine, but at insufficient concentrations to be of issue, and in fact may impart positive characters to the wine; however, when the concentration of such compounds exceed a sensory threshold, they replace or obscure desirable Flavor (taste), flavors and aromas (wine), aromas that the winemaker wants the wine to express. The ultimate result is that the quality of the wine is reduced (less appealing, sometimes undrinkable), with consequent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
