Alcoholic Beverage Chemistry Of Alcoholic Beverages

Alcoholic beverages have been widely used since the remote antiquity by many civilizations around the world, as a component of the standard diet, for hygienic reasons, for their relaxant effects, for recreational purposes, or many other reasons. Some have been invested with symbolic or religious significance, e.g. in Christian Eucharist and Jewish Passover. alcohol is enjoyed immensely as it intoxicates the users.

The use of alcoholic beverages can create chemical dependency to ethanol ( alcoholism), which many societies consider to be a major health problem, public as well as private. Alcoholism often leads to social and financial ruin, and sometimes to early death. Moreover, the psychological and neurological effects of alcohol are often a factor in serious accidents and crimes. Some religions — most notably Islam — believe that, for these and other reasons, the consumption of alcoholic beverages is forbidden, and many governments regulate or restrict them in many ways.

1 Chemistry of alcoholic beverages

The ethanol in alcoholic beverages is almost always produced by fermentation, i.e. the metabolism of carbohydrates (usually sugars) by certain species of yeastSaccharomyces cerevisiae is a yeast used in both baking and brewing. Yeast are a group of unicellular fungi a few species of which are commonly used to leaven bread and ferment alcoholic beverages. Most yeasts belong to the division Ascomycota. A few yeas in the absence of oxygenOxygen is the chemical element in the periodic table that has the symbol O and atomic number 8. The element is very common, found not only on Earth but throughout the universe. Molecular oxygen (O, often called free oxygen on Earth is thermodynamically un. The process of culturing yeast under conditions that produce alcohol is referred to as brewingfermentation lock Brewing is the production of alcoholic beverages through fermentation. This is the method used in beer production, although the term can be used for other drinks such as sake. The term is also sometimes used to refer to any chemical mixi.

1.1 Alcoholic content

The concentrationThis page refers to concentration in the chemical sense. For the psychological concept of concentration, see attention. For the game show of the same name, see concentration (game show). Concentration is a very common concept used in chemistry and related of alcohol in an alcoholic beverage may be specified in percent alcohol by volumeAlcohol by volume ABV is an indication of how much alcohol (expressed as a percentage) is included in an alcoholic beverage. This measurement is assumed as the world standard, although in the United States the predominant measurement is Alcohol by weight (ABV), in percentage by weight (sometimes abbrieviated w/w for weight for weight), or in proofAlcoholic proof is a measure of how much ethanol, or "grain alcohol," is in an alcoholic beverage. The proof number is twice the percentage of the alcohol content measured by volume, at a temperature of 60° Fahrenheit. Therefore "80 degrees proof" is 40%.

Most yeasts cannot grow when the concentration of alcohol is higher than about 18% by volume, so that is a practical limit for the strength of fermented beverages such as wineThis article is about the beverage. See WINE for an article about the software of the same name. Wine is an alcoholic beverage typically made by fermentation of grapes. The word comes from Greek omicron;ινο&sigmaf through Latin vinum, (bot, beer1990s England when people received less than a pint (568 ml) of beer for the price of a pint. A beer is any variety of alcoholic beverages produced by the fermentation of starchy material derived from grains or other plant sources. The production of beer, and sake. Strains of yeast have been developed that can survive in solutions of up to 25% alcohol by volume, but these were bred for ethanol fuel production, not beverage production. Drinks with a higher concentration of alcohol can be produced by distillation of the fermented product.

1.2 Flavoring

Ethanol is a moderately good solvent for many "fatty" substances and essential "oils", and thus facilitates the inclusion of several coloring, flavoring, and aromatic compounds to alcoholic beverages, especially to distilled ones. These flavoring ingredients may be naturally present in the starting material, or may be added before fermentation, before distillation, or before bottling the distilled product. Sometimes the flavor is obtained by allowing the beverage to stand for months or years in barrels made of special wood, or in bottles where scented twigs or fruits — or even insects — have been inserted.

Finally alcoholic beverages can be combined at the time of serving, sometimes with other ingredients, to create cocktails.

2 Uses

In many countries, alcoholic beverages are commonly consumed at the major daily meals (lunch and dinner).

In places and eras with poor public sanitation, such as Medieval Europe, consumption of alcoholic beverages (particularly weak or "small" beer) was one method of avoiding water-borne diseases such as the cholera. Though strong alcohol kills bacteria, the low concentration in beer or even wine will have only a limited effect. Probably the boiling of water, which is required for the brewing of beer, and the growth of yeast, which would tend to crowd out other micro-organisms, were more important than the alcohol itself. In any case, the ethanol (and possibly other ingredients) of alcoholic beverages allows them to be stored for months or years in simple wood or clay containers without spoiling, which was certainly a major factor in their popularity.

In colder climates, strong alcoholic beverages are popularly seen as a way to "warm up" the body, possibly because ethanol is a quickly absorbed source of calories and dilates peripheral blood vessels. Their low freezing point may also have helped their popularity.

In many cultures, both contemporary and historical, alcoholic beverages — mostly because their neurological effects — have also played an important role in various kinds of social interaction. While other psychoactive drugs have sometimes been used for similar purposes, none has been so universally used and accepted as ethanol.

3 History

3.1 Fermented beverages

Fermented alcoholic beverages must have been known since pre-historical times. Beer was certainly known in Babylonia before 4000 BC, as attested by recipes found on clay tablets.

Wine was consumed in Classical Greece at breakfast, and in the 1st century BC it was part of the diet of most Roman citizens. However, both Greeks and Romans generally consumed their wine watered (from 2 parts of wine to 5 parts of water, to 1 part of wine to 4 parts of water). The transformation of water into wine at a wedding feast is one of the miracles attributed to Jesus in the New Testament, and his symbolic use of wine in the Last Supper led to it becoming an essential part of the Catholic Eucharist rite.

In spite of the Quranic ban on alcoholic beverages, wine remained fairly popular in Islamic lands for many centuries, as revealed in the verses of Persian mathematician Omar Khayyam (1040–1131):

"Here with a Loaf of Bread beneath the Bough,

A Flask of Wine, a Book of Verse—and Thou

Beside me singing in the Wilderness—

And Wilderness is Paradise enow." [1]

In Europe during the Middle Ages, beer was consumed by the whole family, thanks to a triple fermentation process — the men had the strongest, then women, then children. A document of the times mentions nuns having an allowance of six pints of ale a day. Cider and pomace wine were also widely available, while grape wine was the prerogative of the higher classes. After the collapse of the Roman Empire, wine production in Europe appears to have been sustained chiefly by monasteries.

By the times the Europeans reached the Americas in the 15th century, several native civilizations had developed alcoholic beverages. According to a post-Conquest Aztec document, consumption of the local "wine" ( pulque) was generally restricted to religious ceremonies, but freely allowed to those over 70 years old (possibly the all-time record for legal drinking age). The natives of South America manufactured a beer-like product from cassava or maize ( cauim, chicha), which had to be chewed before fermentation in order to turn the starch into sugars. (Curiously, the same technique was used in ancient Japan to make sake from rice and other starchy crops.)

The medicinal use of alcoholic beverages was mentioned in Sumerian and Egyptian texts dated from 2100 BC or earlier. The Old Testament recommends giving alcoholic drinks to those who are dying or depressed, so that they can forget their misery.

3.2 Distilled beverages

Although distillation seems to have been known by alchemists in Alexandria (such as Mary the Jewess ), around the 3rd century AD, the development of the still with cooled collector — necessary for the distillation of spirits — was an invention of Islamic alchemists in the 8th or 9th centuries. In particular, Geber (Jabir Ibn Hayyan, 721– 815) observed that heated wine released a flammable vapor, which he described as "of little use, but of great importance to science". Not much later Al-Razi ( 864– 930) described the distillation of alcohol and its use in medicine. By that time, distilled spirits were not just chemical products, but fairly popular beverages: the poet Abu Nuwas (d. 813) describes a wine that "has the colour of rain-water but is as hot inside the ribs as a burning firebrand". The terms "alembic" and "alcohol", and possibly the metaphors "spirit" and acqua vitæ ("life-water") for the distilled product, can be traced to Islamic alchemy.

From Islam, the art of cooled distillation had reached Italy by 1100. In the 13th century Italians were distilling liqueurs from wine and aromatic herbs. By the early 14th century the art was known in Paris, and then it spread throughout Europe. The 13th and 14th centuries saw the birth of many popular European spirits, such as brandy (from the Dutch brandewijn, "burnt wine"), schnapps, sherry, whisky, etc. It also spread eastward, mainly by the Mongols, and was practiced in China by the 14th century.

4 Legal considerations

Most countries have rules forbidding the sale of alcoholic beverages to children. For example, in the Netherlands and Germany, one has to be 16 to buy beer or wine and 18 to buy distilled alcoholic beverages. There are also restrictions on driving after drinking.

In law, sometimes the term "intoxicating agent" is used for a category of substances which includes alcoholic beverages and some drugs. Giving a person these to create an abnormal condition of the mind (such as drunkenness), in order to facilitate committing a crime, may be an additional crime.

Some countries may forbid the commerce or consumption of alcoholic beverages, or restrict them in various ways. During the period known as Prohibition, from 1919 to 1933, it was illegal to manufacture, transport, import, export, or sell alcoholic beverages in the United States. Many Muslim countries, such as Saudi Arabia, prohibit alcohol for religious reasons.

Most countries have laws against drunk driving, driving with a certain concentration of ethanol in the blood. The legal threshold of blood alcohol content ranges from 0.1% to 0.08%, 0.05% and even 0% in different countries.

Most countries also specify a legal drinking age, below which the consumption of alcohol is prohibited. In the US, the legal age in every state has been 21 since the passage of the National Minimum Drinking Age Act in 1984, which tied federal highway funds to states' raising their minimum drinking age to 21.

In many countries, production of alcoholic beverages requires a license, and alcohol production is taxed. In the U.S., the Bureau of Alcohol, Tobacco, Firearms, and Explosives and the Alcohol and Tobacco Tax and Trade Bureau (formerly one organization known as the Bureau of Alcohol, Tobacco and Firearms) enforce federal laws and regulations related to alcohol, though most regulations regarding serving and selling alcoholic beverages are made by the individual states. For example, in the state of Washington, one can only buy bottles of spirits in state-run stores, whereas in many other states, these can be bought in supermarkets. There also exist intrastate regulatory differences, as between Montgomery County, Maryland and the rest of the state. In the UK the Customs and Excise department issues distilling licences.

5 Effects on the human body

5.1 Alcoholic intoxication

In small amounts, ethanol causes a mild euphoria and removes inhibitions. In large doses, ethanol acts as a central nervous system ( CNS) depressant and causes drunkenness (at a blood ethanol content of about 0.1%). At higher contents, alcohol causes intoxication, coma and death. A blood ethanol content above 0.4% can be fatal, although regular heavy drinkers can tolerate somewhat higher levels than non-drinkers.

Alcoholism, the dependency on alcohol, is a major public health problem. Alcoholics develop a number of health problems, with cirrhosis of the liver being the most important one.

Excessive alcohol consumption during pregnancy may cause a series of mental and physical defects in the child, known as fetal alcohol syndrome.

5.2 Action on the brain

Ethanol is quickly absorbed into the bloodstream and reaches the brain. As a small molecule, it is able to cross the blood-brain barrier. The euphorizing effects of ethanol are probably due to its causing the release of endorphins, natural "feel-good" molecules.

The CNS depressant effect likely is due to ethanol's acting on the BK channels. A BK channel is a calcium dependent potassium channel. It has been known to act on GABA receptors, but this is probably just a secondary effect from activation of the BK channels. Its effect on GABA receptors is probably similar to the action of benzodiazepines such as diazepam. GABA is an inhibitory neurotransmitter, meaning it acts to slow down or inhibit nerve impulses. Ethanol increases the effectiveness of GABA acting through GABA_A receptors. When used over a long time, ethanol changes the number and type of GABA receptors, and this is thought to be the cause of the violent withdrawal effects of alcoholics.

Ethanol also interferes with synaptic firing and causes the death of brain cells. This cell death is caused by an increased concentration of intracellular calcium which weakens the electrochemical gradient across the cell membranes. It is this gradient which is the motive force of membrane pumps and channels (cells, especially neurons, quickly die without proper membrane pump and channel function). There is also direct damage to cell membranes from free-radicals that are produced from alcohol metabolism.

5.3 Metabolism of alcohol and action on the liver

The liver contains a special enzyme ( alcohol dehydrogenase) that breaks down alcohols into acetaldehyde, which is turned into acetic acid by the enzyme acetaldehyde dehydrogenase, and then yet another enzyme converts the acetate into fats or carbon dioxide and water. The fats are mostly deposited locally which leads to the characteristic "beer belly". Chronic drinkers, however, so tax this metabolic pathway that things go awry: fatty acids build up as plaques in the capillaries around liver cells and those cells begin to die, which leads to the liver disease cirrhosis. The liver is part of the body's filtration system and if it is damaged then certain toxins build up thus leading to symptoms of jaundice.

The alcohol dehydrogenase of women is less effective than that of men. Combined with the lower amount of water in women's bodies, this means that women typically become drunk earlier than men.

Some people, especially those of East Asian descent, have a genetic mutation in their acetaldehyde dehydrogenase gene, resulting in less potent acetaldehyde dehydrogenase. This leads to a buildup of acetaldehyde after alcohol consumption, causing hangover-like symptoms such as flushing, nausea, and dizziness. These people are unable to drink much alcohol before feeling sick, and are therefore less susceptible to alcoholism. [2], [3] This adverse reaction can be artificially reproduced by drugs such as disulfiram, which are used to treat chronic alcoholism by inducing an acute sensitivity to alcohol.

5.4 Dehydration

Consumption of ethanol has a rapid diuretic effect, meaning that more urine than usual is produced, since ethanol inhibits the production of antidiuretic hormone.

Overconsumption can therefore lead to dehydration (the loss of water). It is difficult to replenish the body's fluids using only alcoholic beverages. As large amounts of alcohol are consumed, the diuretic effect causes the body to lose more water than is contained in the beverage.

5.5 Hangover

A common after-effect of ethanol intoxication is the unpleasant sensation known as hangover, which is partly due to the dehydrating effect of ethanol. Hangover symptoms include dry mouth, headache, nausea and light sensitivity. These symptoms are partly due to the toxic acetaldehyde produced from alcohol by alcohol dehydrogenase, and partly due to general dehydration. The dehydration portion of the hangover effect can be mitigated by drinking plenty of water between and after alcoholic drinks. Other components of the hangover are thought to come from the various other chemicals in an alcoholic drink, such as the tannins in red wine, and the results of various metabolic processes of alcohol in the body, but few scientific studies have attempted to verify this.

5.6 Benefical effects of alcohol

Several studies have suggested that regular consumption of small amounts of wine (especially red) may lower the incidence of coronary heart disease. However, it is unclear whether the benefits identified are due to the alcohol itself, or rather to other compounds, such as polyphenols found specifically in red wine (and also red grapes and red grape juice). The effects could also be due to life-style differences, since wine drinkers are typically more affluent, exercise more, and eat healthier than the average population. Guinness used to be advertised with the slogan "Guinness is good for you". This claim is not backed up by any specific research, although specific properties of Guinness are known to be beneficial - amongst others, it has a high iron content (hence it was historically offered to blood donors), and also contains antioxidants.

6 Types of alcoholic beverages

Alcoholic beverages include low-alcohol-content beverages produced by fermentation of sugar- or starch-containing products, and high-alcohol-content beverages produced by distillation of the low-alcohol-content beverages. Sometimes, the alcohol content of low-alcohol-content beverages is increased by adding distilled product, particularly in the case of wines. Such fortified wines include Port wine and Sherry.

6.1 Non-distilled beverages

Beer
- Ales
  - Barleywine
  - Bitter ale
  - Mild ale
  - Pale ale
  - Porter
    - Stout
  - Real ale
  - Stock ale
- Fruit Beer
- Lager beer
- Small beer
- Wheat beer
Cauim
Chicha
Cider
Kumis
Lappish hags lovepotion
Mead
Perry
Pulque
Sake
Wine

6.2 Distilled beverages

The names of some beverages are determined by the source of the material fermented:

Source	Name of fermented beverage	Name of distilled beverage
grain	beer, ale, sake ( rice)	whiskey (also spelled whisky)
juice of fruits, other than apples or pears	wine (most commonly from grapes)	brandy, Cognac (France), Branntwein (Germany)
juice of apples	("hard") cider	applejack (or apple brandy), Calvados
juice of pears	perry, or pear cider	pear brandy
juice of sugarcane, or molasses	basi, betsa-betsa (regional)	rum, cachaça
juice of agave	pulque	tequila, mezcal
juice of plums	plum wine	slivovitz
pomace	pomace wine	grappa (Italy), Trester (Germany), Marc (France)
honey	mead

Note that in common speech, wine or brandy is made from grapes unless the fruit is specified: "plum wine" or "cherry brandy" for example, although in some cases grape-derived alcohol is added.

In the USA, cider often means unfermented apple juice (see the article on cider), while fermented cider is called hard cider. Unfermented cider is sometimes called sweet cider. Also, applejack was originally made by a freezing process described in the article on cider which was equivalent to distillation but more easily done in the cold climate of New England. In the UK, cider is always alcoholic, and in Australia it can be either.

Two common distilled beverages not listed in the above chart are vodka and gin. Vodka can be distilled from any source ( grain and potatoes being the most common, also industrial cellulose for the cheapest!) but the main characteristic of vodka is that it is so thoroughly distilled as to exhibit none of the flavors derived from its source material. Gin is a similar distillate which has been flavored by contact with herbs and other plant products, especially juniper berries, from which it gets its name.

7 See also

8 External links

Alcoholic beverages

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