ALCOHOL AND ALCOHOLIC DRINKS
The name of the alcohol is derived from the Arabic "al-kuhl" meaning "fine powder". Ethanol, i.e. ethanol, with the chemical formula C2H5OH belongs to the group of organic compounds, hydrocarbon derivatives, characterized by the presence of the OH group in place of the hydrogen atom. Depending on the number of these groups in the molecule, distinguish one alcohol- and polyhydric, however, depending on the number of hydrogen atoms located at the same carbon atom as the OH group - we distinguish primary alcohols (2 atoms), secondary (1 atom) and tertiary.
Ethyl alcohol is monohydric, primary and hence its physical and chemical properties. So it is a colorless liquid, transparent, with a characteristic burning taste and weak, specific smell, flammable, chemically inert, highly hygroscopic (having the property of attracting water), soluble in water in all proportions, dissolving fats, proteins. The specific gravity of ethyl alcohol is approx. 0,8, boiling point - 78.3°C. When burning 1 gram of ethyl alcohol is produced 7,08 calories (tree - 4,5, coal - 7), Therefore, ethyl alcohol is an excellent fuel. Acetaldehyde is obtained from ethyl alcohol by subtracting a hydrogen atom in a catalyzed process; esters are formed by combining ethanol with acids, by combining with metals — alkoxides.
Thanks to its physical and chemical properties, ethyl alcohol is valuable, sometimes an indispensable substance, widely used in industry, chemistry, medicine, household. High calorific value makes alcohol a valuable fuel, hygroscopicity - a dehydrating and drying agent, protein shearing property - disinfectant, the property of dissolving fats - with an organic solvent, low boiling point - heat exchanger. In medicine, ethyl alcohol is used as a solvent (iodine etc.), extractive agent for the preparation of plant extracts, germicide (only at the highest concentrations!), astringent and drying.
For industrial purposes, ethyl alcohol can be produced by chemical synthesis, np. of acetylene or ethylene. But for production so-called ethyl alcohol. consumption (intended for drinking) the process of alcoholic fermentation known since time immemorial is used, followed by distillation and rectification.
Alcoholic fermentation of sugars is the conversion of sugar into ethyl alcohol and carbon dioxide. It proceeds only in the presence of a catalyst, which is an enzyme (leaven, ferment) zymaza, found in yeast. By adding yeast to the crushed stock, which can be any sugar-containing substances (so honey, grapes, fruit, sugarcane etc.) the fermentation process begins, which follows the pattern:
C6H12O6 = 2C2H5OH + 2CO2 + 23 kcal.
In the production of alcohol from crops that do not contain sugar, np. from rye or potatoes, beforehand, the starch contained in them should be decomposed into simple sugars. This process takes place under the influence of ferment, called amylase and found in barley or oat sprouts. By adding amylase-containing sprouted barley (so-called. malt) for overcooked cereal or potatoes, starch is converted into grape sugar:
(C6H10O5)n + H2O = C6H12O6
The sugar obtained in this way is then subjected to alcoholic fermentation.
When the concentration of alcohol in the fermenting solution reaches 14-16%, yeast, which are living cells, are lost and the fermentation process is interrupted in the absence of zymase leaven. Thus, only part of the alcoholic beverages can be produced by fermenting sugars: beer (2 do 6% alcohol content), Apple pie (4—6%), so-called wine. light (6—7,5%) and heavy (above 7,5%), meads (8,5—11%). For stronger drinks, fermentation products are distilled; using the low boiling point of alcohol, the alcohol is evaporated from the aqueous solution and recondensed, already in higher concentration. Alcohol (95%) is obtained through the so-called. rectification, consisting in multiple and very accurate distillation of fermentation products in rectification columns. Spirit can be diluted to any concentration, add flavors and fragrances to it; this is how spirits are made.
They are distilled beverages: cognacs (produced by distilling wine - 48-55%), whisky (50—60%), rum (from sugar cane - 60%), arak (60%), strong, rowanberry, burnouts. Beverages obtained by diluting spirits, to: most vodkas (35—45%), liqueurs (30—40%) i aperitify (14—19%). Wine with an alcohol content above 16% they are called fortified or alcoholized, as they are made by adding spirit to the final product of fermentation.
Both the fermentation process, as well as distillation treatments cause, that there are significant amounts of impurities in the final product, so-called. fuzzy. They are various chemicals: other alcohols (np. methyl and propyl), esters, fats, as well as contaminants from the apparatus - copper compounds, lead etc. The fuselages determine the specific taste and smell of the drink, decide on the so-called. "bouquet" of drink; however, these are usually agents many times more poisonous than ethyl alcohol itself.
In the products of Polski Monopoly Spirytusowy, the permissible amount of these impurities may not exceed 0,3%, natomiast samogon (hooch), various home-made drinks and some imported drinks contain even above 1,5% fuzzy.
Denatured alcohol is not an alcoholic beverage. It is ethyl alcohol produced for technical purposes, not for consumption. It differs from alcoholic beverages by its blue color and repulsive smell, the bottle is also marked with the symbol of poison - "death's head". The denatured alcohol is denatured by the addition of methyl alcohol or pyridine and these substances cannot be separated from the ethyl alcohol by any treatment. On the other hand, methyl alcohol, also produced for technical purposes, does not differ "by eye" from ordinary spirit. Therefore, from time to time there are numerous poisonings with methyl alcohol, sold by thieves to gullible people; therefore one should never buy alcoholic beverages from shady sources and one must be careful, that the bottle is correctly labeled, corked and sealed. Methyl alcohol is a very strong poison; within a few dozen minutes after drinking it, vision loss usually occurs, just a dose 30 grams can already be lethal. Denatured alcohol is also a poisonous liquid, however, it works slower and causes changes that are not as dangerous as methyl alcohol.