Misplaced Pages

#417582

56-399: Red wine is red-coloured wine. Red Wine may also refer to: Red wine The top 20 red grape varieties by acreage (listed alphabetically) are: The next top 30 red grape varieties by acreage (listed alphabetically) are: The first step in red wine production, after picking, involves physical processing of the grapes. Handpicked or machine-harvested grapes are usually tipped into

112-494: A variable void fraction which depends on how the material is agitated or poured. It might be loose or compact, with more or less air space depending on handling. In practice, the void fraction is not necessarily air, or even gaseous. In the case of sand, it could be water, which can be advantageous for measurement as the void fraction for sand saturated in water—once any air bubbles are thoroughly driven out—is potentially more consistent than dry sand measured with an air void. In

168-766: A 52.3% share of total wine sales in 2004, although there are regional disparities, with Quebec favoring it even more. In the United States, there is a balance between white wine, preferred by women, and red wine, favored by men. Red wine is gaining market share in many countries . Although white wine remains preferred in Australia, red wine consumption is experiencing significant growth. In Japan , red wine consumption now surpasses white wine, accounting for 48% of total wine consumed compared to 43% for white wine. While red wine's market share may be increasing relative to other types of wine, overall wine consumption volume

224-629: A marketing tool. Filtration serves to make wine completely clear and to eliminate any remaining yeast cells and bacteria , which could render the bottled wine microbiologically unstable. Wine is normally put into glass bottles with cork stoppers , though aluminium screwcap closures and plastic stoppers are also common. Alternative containers such as Bag-in-Box , TetraPak and plastic bottles are also used. Europe and North America are significant consumers of red wine, with variations in purchasing behaviors among countries. Americans prioritize grape variety when buying wine, while Spaniards focus on

280-551: A pair of rollers, and the gap between them can usually be regulated to allow for light, hard, or no crushing, according to the winemaker 's preference. The mixture of grapes, skins, juice, and seeds is now referred to as must . The must is then pumped to a vessel, often a tank made of stainless steel or concrete, or an oak vat, for fermentation. In common with most modern winemaking equipment, de-stemmers and crushers are normally made of stainless steel (food-grade stainless steel for those parts that come into physical contact with

336-404: A receival bin when they arrive at the winery and conveyed by a screw mechanism to the grape-processing equipment. On arrival at the winery, there is usually a mixture of individual berries, whole bunches (particularly with handpicked grapes), stems, and leaves. The presence of stems during fermentation can lead to a bitter taste in the wine, and the purpose of destemming is to separate grapes from

392-942: A solution sums to density of the solution, ρ = ∑ i ρ i . {\displaystyle \rho =\sum _{i}\rho _{i}.} Expressed as a function of the densities of pure components of the mixture and their volume participation , it allows the determination of excess molar volumes : ρ = ∑ i ρ i V i V = ∑ i ρ i φ i = ∑ i ρ i V i ∑ i V i + ∑ i V E i , {\displaystyle \rho =\sum _{i}\rho _{i}{\frac {V_{i}}{V}}\,=\sum _{i}\rho _{i}\varphi _{i}=\sum _{i}\rho _{i}{\frac {V_{i}}{\sum _{i}V_{i}+\sum _{i}{V^{E}}_{i}}},} provided that there

448-455: A substance does not increase its density; rather it increases its mass. Other conceptually comparable quantities or ratios include specific density , relative density (specific gravity) , and specific weight . The understanding that different materials have different densities, and of a relationship between density, floating, and sinking must date to prehistoric times. Much later it was put in writing. Aristotle , for example, wrote: There

504-399: A temperature increase on the order of thousands of degrees Celsius . In contrast, the density of gases is strongly affected by pressure. The density of an ideal gas is ρ = M P R T , {\displaystyle \rho ={\frac {MP}{RT}},} where M is the molar mass , P is the pressure, R is the universal gas constant , and T

560-411: Is mass divided by volume . As there are many units of mass and volume covering many different magnitudes there are a large number of units for mass density in use. The SI unit of kilogram per cubic metre (kg/m ) and the cgs unit of gram per cubic centimetre (g/cm ) are probably the most commonly used units for density. One g/cm is equal to 1000 kg/m . One cubic centimetre (abbreviation cc)

616-493: Is a substance's mass per unit of volume . The symbol most often used for density is ρ (the lower case Greek letter rho ), although the Latin letter D can also be used. Mathematically, density is defined as mass divided by volume: ρ = m V , {\displaystyle \rho ={\frac {m}{V}},} where ρ is the density, m is the mass, and V is the volume. In some cases (for instance, in

SECTION 10

#1732780995418

672-454: Is aged for some period before bottling, though this can vary from a few days, in the case of Beaujolais Nouveau to 18 months or more in the case of top Bordeaux reds. Aging can take place in stainless-steel or concrete tanks, or in small or large oak barrels. The latter impart some flavour to the wine as a function of their age and size (small, new barrels give more flavour than large, older barrels). Red wines sometimes undergo fining, which

728-406: Is also advisable to not drink red wine during pregnancy . It has been proposed that resveratrol , a polyphenol in red wine, might help prevent heart problems and blood clots if the wine is consumed in small amounts. However, research is lacking and definitive conclusions can not be made with the current evidence. Density Density ( volumetric mass density or specific mass )

784-475: Is declining in several countries. For example, wine consumption in Argentina has consistently decreased, reaching a -10% change from 2003 to 2004. In 2013, China surpassed France and Italy to become the world's largest consumer of red wine. Since red wine contains alcohol, it can have detrimental effects on the liver and pancreas , worsen gout symptoms, and cause strokes when drunk excessively . It

840-416: Is designed to clarify the wine and sometimes to correct faults such as excess tannin. Fining agents include egg white and gelatin . Some red wines, particularly those designed for early drinking, are cold stabilized so as to prevent the precipitation of unsightly tartrate crystals in the bottle. Most wines are filtered at some stage before bottling, although some winemakers use the absence of filtration as

896-489: Is equal to one millilitre. In industry, other larger or smaller units of mass and or volume are often more practical and US customary units may be used. See below for a list of some of the most common units of density. The litre and tonne are not part of the SI, but are acceptable for use with it, leading to the following units: Densities using the following metric units all have exactly the same numerical value, one thousandth of

952-405: Is important to maximize contact between the cap of skins and the liquid phase. This can be achieved by: Fermentation produces heat and if left uncontrolled the temperature of the fermenting may exceed 40 °C (104 °F), which can impair flavour and even kill the yeast. The temperature is therefore often controlled using different refrigeration systems. Winemakers have different opinions about

1008-403: Is necessary to have an understanding of the type of density being measured as well as the type of material in question. The density at all points of a homogeneous object equals its total mass divided by its total volume. The mass is normally measured with a scale or balance ; the volume may be measured directly (from the geometry of the object) or by the displacement of a fluid. To determine

1064-453: Is small. The compressibility for a typical liquid or solid is 10   bar (1 bar = 0.1 MPa) and a typical thermal expansivity is 10   K . This roughly translates into needing around ten thousand times atmospheric pressure to reduce the volume of a substance by one percent. (Although the pressures needed may be around a thousand times smaller for sandy soil and some clays.) A one percent expansion of volume typically requires

1120-488: Is so great a difference in density between salt and fresh water that vessels laden with cargoes of the same weight almost sink in rivers, but ride quite easily at sea and are quite seaworthy. And an ignorance of this has sometimes cost people dear who load their ships in rivers. The following is a proof that the density of a fluid is greater when a substance is mixed with it. If you make water very salt by mixing salt in with it, eggs will float on it. ... If there were any truth in

1176-428: Is so much denser than air that the buoyancy effect is commonly neglected (less than one part in one thousand). Mass change upon displacing one void material with another while maintaining constant volume can be used to estimate the void fraction, if the difference in density of the two voids materials is reliably known. In general, density can be changed by changing either the pressure or the temperature . Increasing

SECTION 20

#1732780995418

1232-487: Is that color and fruit flavours are extracted into the aqueous solution, without extraction of tannins which takes place in post-fermentation maceration when alcohol is present. This practice is by no means universal and is perhaps more common in New World winemaking countries. Once the must is in a fermentation vessel, yeast naturally present on the skins of the grapes, or in the environment, will sooner or later start

1288-609: Is the absolute temperature . This means that the density of an ideal gas can be doubled by doubling the pressure, or by halving the absolute temperature. In the case of volumic thermal expansion at constant pressure and small intervals of temperature the temperature dependence of density is ρ = ρ T 0 1 + α ⋅ Δ T , {\displaystyle \rho ={\frac {\rho _{T_{0}}}{1+\alpha \cdot \Delta T}},} where ρ T 0 {\displaystyle \rho _{T_{0}}}

1344-418: Is the densest known element at standard conditions for temperature and pressure . To simplify comparisons of density across different systems of units, it is sometimes replaced by the dimensionless quantity " relative density " or " specific gravity ", i.e. the ratio of the density of the material to that of a standard material, usually water. Thus a relative density less than one relative to water means that

1400-487: Is the density at a reference temperature, α {\displaystyle \alpha } is the thermal expansion coefficient of the material at temperatures close to T 0 {\displaystyle T_{0}} . The density of a solution is the sum of mass (massic) concentrations of the components of that solution. Mass (massic) concentration of each given component ρ i {\displaystyle \rho _{i}} in

1456-542: The displacement of the water. Upon this discovery, he leapt from his bath and ran naked through the streets shouting, "Eureka! Eureka!" ( Ancient Greek : Εύρηκα! , lit.   'I have found it'). As a result, the term eureka entered common parlance and is used today to indicate a moment of enlightenment. The story first appeared in written form in Vitruvius ' books of architecture , two centuries after it supposedly took place. Some scholars have doubted

1512-679: The AOC, and Swiss consumers seek the best price. In the United Kingdom , red wine consumption volume increased by 35.71% between 2001 and 2005, making it the most consumed wine in the country , accounting for over half of total wine consumption. Red wine represents 52% of total wine consumption in Spain, 55.6% in Italy in 2004, and 70% in Switzerland. In Canada , red wine dominates with

1568-447: The United States oil and gas industry), density is loosely defined as its weight per unit volume , although this is scientifically inaccurate – this quantity is more specifically called specific weight . For a pure substance the density has the same numerical value as its mass concentration . Different materials usually have different densities, and density may be relevant to buoyancy , purity and packaging . Osmium

1624-431: The accuracy of this tale, saying among other things that the method would have required precise measurements that would have been difficult to make at the time. Nevertheless, in 1586, Galileo Galilei , in one of his first experiments, made a possible reconstruction of how the experiment could have been performed with ancient Greek resources From the equation for density ( ρ = m / V ), mass density has any unit that

1680-467: The alcoholic fermentation, in which sugars present in the must are converted into alcohol with carbon dioxide and heat as by-products. Many winemakers, however, prefer to control the fermentation process more closely by adding specially selected yeasts usually of the species Saccharomyces ellipsoideous . Several hundred different strains of wine yeast are available commercially, and many winemakers believe that particular strains are more or less suitable for

1736-404: The body then can be expressed as m = ∫ V ρ ( r → ) d V . {\displaystyle m=\int _{V}\rho ({\vec {r}})\,dV.} In practice, bulk materials such as sugar, sand, or snow contain voids. Many materials exist in nature as flakes, pellets, or granules. Voids are regions which contain something other than

Red Wine - Misplaced Pages Continue

1792-407: The bottom of a fluid results in convection of the heat from the bottom to the top, due to the decrease in the density of the heated fluid, which causes it to rise relative to denser unheated material. The reciprocal of the density of a substance is occasionally called its specific volume , a term sometimes used in thermodynamics . Density is an intensive property in that increasing the amount of

1848-416: The case of non-compact materials, one must also take care in determining the mass of the material sample. If the material is under pressure (commonly ambient air pressure at the earth's surface) the determination of mass from a measured sample weight might need to account for buoyancy effects due to the density of the void constituent, depending on how the measurement was conducted. In the case of dry sand, sand

1904-405: The considered material. Commonly the void is air, but it could also be vacuum, liquid, solid, or a different gas or gaseous mixture. The bulk volume of a material —inclusive of the void space fraction — is often obtained by a simple measurement (e.g. with a calibrated measuring cup) or geometrically from known dimensions. Mass divided by bulk volume determines bulk density . This is not

1960-710: The density can be calculated. One dalton per cubic ångström is equal to a density of 1.660 539 066 60 g/cm . A number of techniques as well as standards exist for the measurement of density of materials. Such techniques include the use of a hydrometer (a buoyancy method for liquids), Hydrostatic balance (a buoyancy method for liquids and solids), immersed body method (a buoyancy method for liquids), pycnometer (liquids and solids), air comparison pycnometer (solids), oscillating densitometer (liquids), as well as pour and tap (solids). However, each individual method or technique measures different types of density (e.g. bulk density, skeletal density, etc.), and therefore it

2016-427: The density of a liquid or a gas, a hydrometer , a dasymeter or a Coriolis flow meter may be used, respectively. Similarly, hydrostatic weighing uses the displacement of water due to a submerged object to determine the density of the object. If the body is not homogeneous, then its density varies between different regions of the object. In that case the density around any given location is determined by calculating

2072-488: The density of a small volume around that location. In the limit of an infinitesimal volume the density of an inhomogeneous object at a point becomes: ρ ( r → ) = d m / d V {\displaystyle \rho ({\vec {r}})=dm/dV} , where d V {\displaystyle dV} is an elementary volume at position r → {\displaystyle {\vec {r}}} . The mass of

2128-419: The gods and replacing it with another, cheaper alloy . Archimedes knew that the irregularly shaped wreath could be crushed into a cube whose volume could be calculated easily and compared with the mass; but the king did not approve of this. Baffled, Archimedes is said to have taken an immersion bath and observed from the rise of the water upon entering that he could calculate the volume of the gold wreath through

2184-400: The grapes are also crushed, but pressing usually does not take place till after or near the end of fermentation with the time of skin contact between the juice and grapes leaching color , tannins , and other phenolics from the skin. Approximately 60-70% of the available juice within the grape berry, the free-run juice , can be released by the crushing process and does not require the use of

2240-552: The grapes are sent through a crusher/de-stemmer , 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 white wine production, pressing usually takes place immediately after crushing and before primary fermentation . In red wine production,

2296-412: The grapes more gently than continuous presses. The press wine is often kept separate from the free-run, and kept for later blending or disposing. A second microbiological transformation commonly takes place after the alcoholic fermentation of red wines. This is usually referred to as malolactic fermentation (MLF), in which malic acid , naturally present in grape juice, is converted into lactic acid under

Red Wine - Misplaced Pages Continue

2352-460: The grapes). The preservative sulfur dioxide is commonly added when grapes arrive at the winery. The addition rate varies from zero, for perfectly healthy grapes, to up to 70 mg/litre, for grapes with a high percentage of rot. The purpose is to prevent oxidation and sometimes to delay the onset of fermentation . Macerating enzymes (for instance glucanases ) may also be added at this stage, to aid extraction of color and fruit flavours from

2408-399: The ideal temperature for fermentation, but in general cooler temperatures (25–28 °C; 77–82 °F) produce fruitier red wines for early drinking while higher temperatures (28–35 °C; 82–95 °F) produce more tannic wines designed for long aging. Winemakers will usually check the density and temperature of the fermenting must once or twice per day. The density is proportional to

2464-575: The influence of bacteria (it is not strictly a fermentation). MLF is almost universally practised for red wines. It often occurs naturally, owing to the presence of lactic acid bacteria in wineries, but there are also commercially available preparations of bacteria to inoculate for MLF if necessary. Once the MLF is complete, the red wine is usually racked (decanted) off its lees (dead yeast cells and other solids), and has sulfur dioxide preservative added to avoid oxidation and bacterial spoilage. Most red wine

2520-411: The press. The remaining 30-40% that comes from pressing can have higher pH levels, lower titratable acidity , potentially higher volatile acidity and higher phenolics than the free-run juice depending on the amount of pressure and tearing of the skins and will produce more astringent, bitter wine. Winemakers often keep their free-run juice and pressed wine separate (and perhaps even further isolate

2576-416: The pressure always increases the density of a material. Increasing the temperature generally decreases the density, but there are notable exceptions to this generalization. For example, the density of water increases between its melting point at 0 °C and 4 °C; similar behavior is observed in silicon at low temperatures. The effect of pressure and temperature on the densities of liquids and solids

2632-402: The same thing as the material volumetric mass density. To determine the material volumetric mass density, one must first discount the volume of the void fraction. Sometimes this can be determined by geometrical reasoning. For the close-packing of equal spheres the non-void fraction can be at most about 74%. It can also be determined empirically. Some bulk materials, however, such as sand, have

2688-405: The skins and to facilitate pressing. Tannin may be added now, later in the winemaking process, or not at all. Tannin can be added to help stabilize colour, to prevent oxidation, and to help combat the effects of rot. Some winemakers prefer to chill the must to around 10 °C (50 °F), to allow a period of pre-fermentation maceration ("cold soaking"), of between one and four days. The idea

2744-414: The stems and leaves. Mechanical de-stemmers usually consist of a rotating cage perforated with grape-sized holes. Within this cage is a concentric axle with arms radiating towards the inner surface of the cage. Grapes pass through the holes in the cage, while stems and leaves are expelled through the open end of the cage. After destemming, the grapes are commonly lightly crushed. Crushers usually consist of

2800-465: The stories they tell about the lake in Palestine it would further bear out what I say. For they say if you bind a man or beast and throw him into it he floats and does not sink beneath the surface. In a well-known but probably apocryphal tale, Archimedes was given the task of determining whether King Hiero 's goldsmith was embezzling gold during the manufacture of a golden wreath dedicated to

2856-426: The substance floats in water. The density of a material varies with temperature and pressure. This variation is typically small for solids and liquids but much greater for gases. Increasing the pressure on an object decreases the volume of the object and thus increases its density. Increasing the temperature of a substance (with a few exceptions) decreases its density by increasing its volume. In most materials, heating

SECTION 50

#1732780995418

2912-408: The sugar content and will be expected to fall each day as the sugar is converted into alcohol by fermentation. Pressing in winemaking is the process where juice is extracted from grapes. This can be done with the aid of a winepress , by hand, or even by the weight of the grape berries and clusters themselves. Historically, intact grape clusters were trodden by feet , but in most wineries today,

2968-554: The value in (kg/m ). Liquid water has a density of about 1 kg/dm , making any of these SI units numerically convenient to use as most solids and liquids have densities between 0.1 and 20 kg/dm . In US customary units density can be stated in: Imperial units differing from the above (as the Imperial gallon and bushel differ from the US units) in practice are rarely used, though found in older documents. The Imperial gallon

3024-404: The vinification of different grape varieties and different styles of wine. It is also common to add yeast nutrient at this stage, often in the form of diammonium phosphate. Soon after the must is placed in the fermentation vessel, a separation of solid and liquid phases occurs. Skins float to the surface, forming a cap. In order to encourage efficient extraction of colour and flavour components, it

3080-523: The wine produced by different pressure levels/stages of pressing) during much of the winemaking process to either bottle separately or later blend portions of each to make a more complete, balanced wine. In practice the volume of many wines are made from 85 to 90% of free run juice and 10-15% pressed juice. There are many different types of wine presses, but they can be broadly divided into continuous presses and tank presses. Modern winemaking tends to favour tank presses with pneumatic membranes, which squeeze

3136-443: Was based on the concept that an Imperial fluid ounce of water would have a mass of one Avoirdupois ounce, and indeed 1 g/cm ≈ 1.00224129 ounces per Imperial fluid ounce = 10.0224129 pounds per Imperial gallon. The density of precious metals could conceivably be based on Troy ounces and pounds, a possible cause of confusion. Knowing the volume of the unit cell of a crystalline material and its formula weight (in daltons ),

#417582