The separation of alcohol for pleasure from a mash by distillation is called distillation and the product is often called brandy . In contrast to distillation in the context of the isolation and purification of chemicals , the goal here is not to obtain a substance as pure as possible, but to obtain a tasty solution from alcohol, water and aromatic substances .
It is believed that the distillation of wine for the production of high-proof brandy on a larger scale was first practiced around 1000 AD in the Byzantine Empire . The alchemists of the Middle Ages improved the cooling performance of the equipment used and thus the yield by using very long cooling tubes. The alcohol products obtained with it were called aqua ardens , "burning water" (cf. fire water ); they still contained high proportions of water.
Later it was possible to produce alcohol in higher concentrations by repeated distillation. The first evidence of this can be found in the 13th century in the writing De virtutibus aquae vitae (“Of the virtues of the water of life”) by the Florentine doctor and scholar Taddeo Alderotti , who describes the method necessary for this very thoroughly: “Distill until you have half The amount of wine poured in. Take away what is left in the flask. But distill the distillate again and collect 7/10 of it, remove the rest again from the flask, distill the distilled again and collect 5/7 of it. The first third of the distillate is the best and burns, the second third is less good, the third even less and the residue in the flask is nothing ”.
After seven such distillations the water is called perfecta and after ten distillations perfectissima . Since this laborious procedure was very expensive, one was usually content with four distillation. In the following time, several practitioners of alchemy produced the aqua ignea rectificata (purified fire water) and finally the aqua vitae rectificata (purified water of life), which can only be used for medicinal purposes.
Since alcohol had a reputation for helping against the plague, after the great outbreak of the plague between 1347 and 1350 everyone tried to the best of their ability to produce the miracle water on their own; often not only for medical reasons, but also for pleasure. In the late Middle Ages, many states and imperial cities saw themselves forced to enact laws against alcoholism .
The Strasbourg doctor Hieronymus Brunschwig (1450 to 1513) wrote numerous distillation books, such as the so-called "Great Distilling Book" from 1512, an extensive work of more than 600 pages. It contains recipes for the production of herbal extracts as well as instructions for use in the event of illness and illustrations of stills.
Since around the 15th century, commercial production of distilled beverages, often with local characteristics, began in most European countries. In 1411, the “burning water” was distilled from wine in the south of France: Armagnac , which is still valued today and named after the landscape there. About a century later, Calvados began to be distilled from fermented apple juice in Caen and other cities in Normandy . At the beginning of the 16th century, the high quality brandy of the same name , which is still world famous today, was finally produced in the small town of Cognac in southwest France . One of the founders of the Dutch alcohol industry was Lucas Bols , who in 1575 set up the first heated with peat Evaporator on the outskirts of Amsterdam and laying the foundation for the Genever wondered later from the turn of two centuries in London the Gin emerged.
The focus was then on the ever more precise separation of the various substances by means of multi-stage reactors, the removal of undesirable components such as fusel oils and the development of large-scale industrial processes such as the continuous distillation process.
Mash contains approx. 3 to 12 vol .-% alcohol (with modern yeast cultures also up to 20 vol .-%), further components are aldehydes , esters , higher alcohols of fusel oil character and volatile organic acids such as acetic acid . These are important aroma components for fruit brandies.
The distillation of a fermented mash should largely separate and concentrate the alcohol it contains. Typical, value-determining aroma components of a volatile nature should also be transferred into the distillate, while quality-reducing secondary components of alcoholic fermentation or undesired metabolic products of microorganisms should remain in the distillate residue, the vinasse , if possible . The stillage can be used as fodder, fertilizer or in biogas plants .
The components of a mash can be roughly divided into volatile and non-volatile substances:
- Non-volatile mash materials are those that do not become vaporous during a distillation. They include all solid mash components, such as kernels, peel, pulp remains, yeast cells and other microorganisms.
- Liquid or dissolved substances are by-products of alcoholic fermentation such as glycerine and succinic acid , undesirable products of yeast (protein, amino acids), undesirable ingredients in fruit such as non-volatile fruit acids , pectins , minerals, phenolic substances , coloring agents , etc.
When heated, volatile constituents change into a vaporous state and form the distillate. It can be divided into three fractions (sections):
- First, volatile substances such as acetaldehyde , the poisonous alcohol methanol and low-boiling esters evaporate . This first fraction forms the inedible forerun .
- This is followed by the high quality middle course, also known as the "heart", from which the spirit is obtained.
- Finally, there is the higher-boiling finish that characterizes the fusel oils . The distillation can be stopped when this fraction is reached in order to save fuel.
There are two main types of distillation, continuous and batch distillation.
In the continuous firing of the alcohol from the mash filled with internal bubble evaporated and in the subsequent condenser condenses. The distillation process is carried out without interruption by continuously adding new mash and is more economical for the production of large quantities. One is usually cooler than the column with bubble trays used with good separation efficiency a high alcohol concentration in distillate possible. The continuous process is particularly suitable for the production of large quantities of agricultural alcohol .
The inventor of the distillation column is the Belgian engineer Jean Baptiste Cellier-Blumenthal (1768–1840); he also applied for the patent for it.
Patent burning process
The patent still distilling, continuous distilling, column still distilling or Coffey still distilling (Coffey distilling process) is a continuous distilling process according to Aeneas Coffey , which is used in the production of grain whiskey . Here, malted and unmalted grains are mixed and whiskey is produced from them in a relatively cheap and fast process. The distillation takes place in a Patent or Coffey distillation device (also called a column device because of the copper columns), and the distillate is drawn off with a higher alcohol content.
The process was invented by the Scottish Robert Stein and tested in 1826, improved in the following years by the Irishman Aeneas Coffey . With the fuel columns, a distillate with a maximum alcohol content of 94.8 percent by volume is produced, which, thanks to continuous burning, brings an immense cost advantage.
In the case of double firing, two, sometimes three, complete firing cycles are carried out. First, all alcohol is extracted from the mash with raw or coarse brandy (outdated: rough brandy). During the second, decisive distillation, the fine distillate, the coarse brandy, consisting of water, about 25 to 35% alcohol by volume, aromas and fusel oil, is distilled for the second time. Three fractions are obtained by slowly increasing the temperature :
- The boiling at low temperature flow contains undesirable and sometimes toxic ingredients such as methanol , acetone and acetaldehyde . Complete separation of the methanol is not possible in the incineration plants that are usually used. For this reason, according to Regulation (EC) No. 110/2008 (Spirits Regulation) , a Williams pear brandy can and may contain up to 13.5 g of methanol per liter of pure alcohol. With an ethanol content of 40% by volume, this corresponds to a content of about 5.4 g of methanol per liter of Williams pear brandy. Poisoning with methanol is mainly due to the blurring of spirits with methanol.
- At a higher temperature, the valuable middle course boils with ethanol, water and the aromatic substances. The middle course begins with 70 to 80% alcohol by volume and slowly decreases as the distillation progresses. The end of the fine brandy is between 45 and 50% alcohol for pome fruit and 50 to 55% alcohol by volume for stone fruit.
- If the boiling temperature is increased further, the higher-boiling tail ends up with the fusel alcohols propanol , butanol , hexanol , isoamyl alcohol , isobutyl alcohol or pentanol . The lag is the portion that expires below 45%.
In order to produce high-quality fine brandy, it is important that the heating is slow, so that the volatile, undesirable substances are separated out in advance. If it is heated up too much, the full-fledged fruity aromas and the undesirable volatile substances also go into the unusable forerun and are thus lost. From 100 liters of rough brandy you get 25 to 35 liters of fine brandy.
In the case of single distillation, the starting material is always the mash itself. The procedure corresponds to that of fine distillation in double distillation, the alcohol content in the distillate is lower, but the flavor content is high. With the help of a rectification column , however, high-percentage alcohols can also be obtained from single distillation. By increasing the sugar concentration in the mash, alcohol-resistant yeasts can be used to obtain a high-percentage mash (up to 20% by volume of alcohol), which allows the production of brandy with over 40% by volume of alcohol with a simple fire.
Pot still process
For the production of Scottish malt whiskey , Irish pot still whiskey and bourbon whiskey in smaller distilleries, the mash is distilled two or three times in copper stills that run upwards in a swan neck . The first distillation process takes place in the so-called wash or wine still, after which the liquid has an alcohol content of 20 to 26 percent by volume . After the second distillation process in the spirit still, the distillate reaches an alcohol content of 60 to 75 percent by volume. Attempts to replace the copper with cheaper, easier to process and less corrosion-prone metals have all failed due to the unsatisfactory taste of the whiskey produced in it. However, not only the material used, but also the shape of the pot still affects the taste of the whiskey. Firing in stills is discontinuous , as only one batch can be processed at a time.
The pot still process is usually not used in mass production as it is quite laborious. The still must be cleaned without residue between each firing process.
Lomond Still Procedure
The Lomond still , developed in 1955 by Alistair Cunningham and Arthur Warren , which is a kind of hybrid of pot still and column still with a cylindrical shape and movable copper plates inside, could not prevail . The backflow could be regulated by the copper plates, but they also had to be cleaned regularly, which was very time-consuming. It was used in several distilleries and was recently only used at Bruichladdich and Scapa - without the copper plates. Then new Lomond stills were set up in the new InchDairnie distillery in 2015, which have been used in experimental trials since the start of operations in 2016.
Firing technology for discontinuous firing
The internal bubble is a heated vessel in which the mash is heated to evaporate the volatile ingredients.
The heat required for distillation can be generated and given off in different ways:
- Direct firing: The still is heated directly by the burner.
- Indirect firing: The heat is supplied via a water bath or with steam. This distributes the heat more evenly, which prevents the mash from burning.
Natural gas or heating oil are usually used as fuel . Electric heaters are rarely used for cost reasons. Wood heating systems are difficult to regulate and are therefore only found in old distilleries. In order to minimize heat loss, the still is usually walled in or insulated in some other way.
An optional agitator mixes the mash and ensures more even heat distribution. This improves the separation efficiency, as the characteristic components of the respective fraction evaporate at the same time (and are not carried over into the next one) and prevents the mash from burning.
Filling and emptying
The mash is pumped into the still via a filling opening or a pipe connection. After the firing, the still is emptied through a flap .
Spirit helmet and spirit pipe
The spirit helmet is cylindrical or spherically widened and lies above the pot still. The alcohol vapors collect in it and are fed into the amplifier unit via the spirit pipe.
The amplifier unit is only used in a simple fire and consists of two functional components. It is located next to, in high rooms, above the still. It is used to condense the water from the alcohol vapors, the alcohol content is increased accordingly. This enables a distillate with a high alcohol content to be obtained in one distillation process, which is otherwise only possible with two or three distillations. This significantly increases the profitability of the distillery.
A column of mostly three bubble-cap trays . Water and alcohol condense on each bell bottom and form a liquid level. Further hot alcohol and water vapors continuously flow through this, from which above all the water, as a higher-boiling component, condenses in the liquid level. The water vapors are virtually washed out. The heat released by the condensation in turn allows alcohol to evaporate. The liquid level rises, excess liquid is drained through an overflow into the bottom tray, from the bottom tray it is returned to the still with a high proportion of water and little alcohol. As a result, vapors with a higher alcohol content and less water reach the next bubble cap. Each floor has its own water-alcohol mixture ratio and vapors with a high alcohol content reach the upper part of the amplifier unit, the dephlegmator.
The dephlegmator is a condenser that causes a further concentration. The cooling water flow is ideally regulated in such a way that the temperature is above the boiling point of the alcohol, but significantly below that of the water. Alcohol vapors can pass the dephlegmator, water condenses and drips back onto the bell bottom, less cooling lets more water through.
Many bubble trays and a cold dephlegmator result in a better separation of water and alcohol, but the aromas are also separated from the distillate. Three floors have proven to be the best and deliver the best results with the skill of the master distiller when operating the cooling. Individual bubble trays and the dephlegmator can also be switched off if necessary.
The catalyst or cyanide separator removes ethyl carbamate or hydrocyanic acid from the distillate. These substances are mainly found in stone fruit mash , the raw materials are contained in the kernels. The effective component of the catalyst is copper, so pot stills are almost always made of copper or brass and not easy-care stainless steel. As a rule, the catalyst can be bridged when it is not needed, as is the case with pome fruit mashes . Simple systems often do not have a catalyst.
The hot distillate vapor enters the cooler at the top via another spirit pipe, while cold water is fed into cooling tubes in countercurrent from below . The cooling water absorbs the heat of the steam, which condenses and becomes a liquid distillate. Tube coolers made of stainless steel are used almost exclusively. At the bottom of the cooler is the template, a small, elongated container with an overflow. In the distillate that collects here, an alcohol meter floats to determine the alcohol content. This is decisive for the right time to separate the pre-, middle and on-carriage.
Further processing of the distillate
The presence of atmospheric oxygen plays an important role in the strengthening and formation of new aromas in the course of storage. New aromatic substances are formed, the spirit becomes milder, rounder, more harmonious and thus the taste is considerably improved. Important chemical reactions that favor ripening processes are esterifications and acetalizations . In the ester bond, fruit acids and alcohols, including fusel alcohols, combine with water to form various aromatic substances. Acetals, on the other hand, are formed from the combination of alcohols with aldehydes, whereby water is also split off. Particularly in view of the fact that this reaction removes much of its effect from the unpleasant acetaldehyde , the acetalization has a considerable aroma-improving effect. The ripening processes take place in both high-percentage and diluted distillates. It is therefore not necessary to reduce distillates to a lower alcohol concentration with water before storage.
Storage is one of the most important steps for some spirits, such as whiskey or brandy. Wooden barrels, which were often treated differently beforehand, serve as storage containers. During a storage period of a few years, the spirit takes on the color and taste of the barrel, and air can enter through the pores in the barrel. Fruit brandies are usually stored in stainless steel, glass or glazed earthenware containers for up to a year. The earthenware, like wood, can breathe, steel tanks and glass balloons are often only three-quarters full to create a reaction surface for the air. On a large scale, stainless steel is the most commonly used storage material.
It is difficult to provide general information about the storage temperature, as constant temperatures are preferred for certain types of food, and strong temperature fluctuations are desirable in other cases.
Dilute to drinking strength
The still undiluted distillate has an alcohol content of 60% by volume or more and is therefore mostly inedible. This is reduced to drinking strength with drinking water , which is often treated with regard to the minerals it contains. If tap water were added, the distillate would immediately be slightly cloudy. The alcohol removes the dissolving behavior of the water constituents and lets them flocculate. The edible spirit usually has between 37.5 percent by volume and 40 percent by volume, the alcohol content is often historical or determined by legal backgrounds (for legally protected designations of origin). In the case of strong (i.e. high-proof) spirits, the alcohol can be too hot or dominant; this often means that the valuable aromas are masked. With a lower alcohol content, the spirits often taste empty, bland or even sticky. The alcohol content must be set very precisely, as only very small deviations are legally tolerated, a maximum of 0.3% by volume absolute. The alcohol content is measured indirectly via the density with an alcohol meter, it depends on the ratio of water to alcohol and the temperature. Official tables help with dilution, which indicate the alcohol content for the measured values of alcohol content and temperature at a standard temperature of 20 ° C as well as the corresponding amount of water required. Diluted distillates are often called fine brandies .
In addition to water, other ingredients such as sugar and flavorings can be added to the end product in some countries (e.g. Italy).
If the alcohol content is reduced sufficiently by the addition of water, tiny oil droplets suddenly form, creating an oil-in-water emulsion . The light is scattered at the interfaces between water and oil droplets ( Tyndall effect ), which causes the milky-white turbidity. The coloring is not based on a chemical reaction that would have formed a whitish substance, but is of a physical nature ( Louche effect ).
This cloudiness depends heavily on the components of the distillate and is then filtered out. Many opacifying substances fall out and are visually unattractive, especially when cooled. Filtration is therefore carried out using microfilters even at temperatures around freezing point, so that even a spirit stored in the refrigerator always remains clear for the consumer. However, strong cooling during enjoyment means that the aromas do not come into their own and the full taste cannot develop. Inferior quality products, however, benefit from the cooling, since bad-tasting fusel oils , if available, taste very little through. Therefore, most spirits that are drunk straight should not be taken out of the refrigerator. With vodka, which has a very neutral taste, it is common to drink it ice cold.
The production of brandy (distilling) and processing was subject to the brandy monopoly until 2017 . The supervision was carried out by the customs administration. From January 1, 2018, taxation and other obligations will be based on the Alcohol Tax Act , which replaces the Spirits Monopoly Act.
According to the Alcohol Tax Act (federal law on a consumption tax on alcohol and alcoholic goods), alcohol and alcoholic goods (products) that are produced in Austria (with the exception of the area of the local communities Jungholz in Tyrol and Mittelberg in Vorarlberg) are subject to alcohol tax. Production for personal use from self-produced alcohol-forming substances is also subject to tax liability (with a reduced tax rate of EUR 6.48 per liter) as production under compensation (Section 55 Alcohol Tax Act) and must be applied for as such (compensation notification), which can also be done online can.
In Switzerland, the federal law on distilled water (Alcohol Law, SR 680) of June 21, 1932, which is currently undergoing a total revision, applies . A license from the Swiss Alcohol Administration (EAV ) is required to produce or trade spirits (distilled water) . Depending on the size and type of farm, farmers are entitled to a tax-free quota of alcohol. The yield must be accounted for precisely with the EAV.
The traditional “Störbrenner” travels with its mobile distillery to the farms from January to March. The distillery consists of a steam boiler fired with wood from the farmers, two to three distillery ports (pressure 5 bar), the rectification column and the countercurrent cooler. The farmers bring their barrels with the fermented fruit, the mash. Apples, pears and quinces are burned first, followed by the cherries and finally the rest of the stone fruit . The aroma of the distilled schnapps depends largely on the quality of the goods delivered.
- The distillery through the ages
- Tages-Anzeiger from February 20, 2006: High-proof something oozes out of the mobile schnapps distillery
- Zieberlizunft Sigigen: Zieberlischnaps
- Westermeyer J .: Cross-cultural studies on alcoholism . In: Goedde HW: Alcoholism: Biomedical and genetic aspects. Pergamon Press, New York, pp. 305-311.
- Gundolf Keil : "Aqua ardens". From the short treatise to the profession of brandy distiller. In: Hagen Keller , Christel Meier , Thomas Scharf (eds.): Writing and life practice in the Middle Ages. Capture, preserve, change. Files of the International Colloquium 8. – 10. June 1995. Wilhelm Fink, Munich 1999 (= Münstersche Mittelalter-Schriften. Volume 76), pp. 267-278.
- Avoxa - Media Group German Pharmacists G: Methanol: Deadly Brother of Ethanol. In: pharmische-zeitung.de. February 21, 2012, accessed November 4, 2018 .
- Dieter Osteroth: Pocket book for food chemists and technologists. Springer-Verlag, 2013, ISBN 978-3-642-58220-2 , p. 340 ( limited preview in Google book search).
- Nina Bublitz: Why methanol is so dangerous. In: stern.de . April 6, 2009, accessed November 4, 2018 .
- ap: Deadly methanol scandal in the Czech Republic: 31 suspects charged with alcohol abuse. In: rp-online.de. January 14, 2014, accessed November 4, 2018 .
- 23 dead from adulterated raki. In: sueddeutsche.de . November 1, 2015, accessed November 4, 2018 .
- http://www.schnapsbrennen.at/prodbeschreibung.php#turbo Bettina Malle and Helge Schmickl distilling schnapps as a hobby
- Explanations on the Jameson Distillery Tour, Dublin, Ireland.
- Archive link ( Memento of the original from May 1, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- Excise duties / liquor monopoly
- Alcohol Tax Act as amended in Federal Law Gazette I No. 151/2009
- Schnapps: One fifth burns black. In: steiermark.orf.at. April 9, 2012, accessed December 1, 2017 .
- Swissinfo: Sturgeon burners on the move