Liquors

Malt wine is made from fermented malt extract (the hot water extract of whole meal malt). Mal-ton wine is made in the same way, except that sucrose is added at 1.8-times the amount of malt in order to increase the sugar and alcohol content of the wine. The wort is then soured by the action of lactic acid bacteria (0.6-0.8% lactic acid, final concentration). The acid fermentation is stopped by heating the wort to 78 °C and, after inoculation with a pure yeast culture, the wort is fermented to an alcohol content of 10-13%. The beverage thus formed has the character of a dessert wine, but is different because of its high content of lactic acid and its malt extract flavor. Mead is an alcoholic liquor made of fermented honey, malt and spices, or just of honey and water (not more than 21 water per kg of honey). Since early times, mead has been widely consumed in Europe and, even today, it is enjoyed the most of all the wine beverages in eastern and northern Europe. 

These wines are similar to vermouth aperitif wines. They are flavored by different herbs and spices. Ginger-flavored wine is an exanqtle of this type of wine. 

Spirits or liquors are alcoholic beverages in which the high alcohol concentration is achieved by distillation of a fermented sugar-containing liquid. Examples are distilled wines (brandies), liqueurs, punch extracts and alcohol-containing mixed drinks. Table 20.27 compares the alcohol consumption with respect to spirits, wine and beer in selected countries. 

Other wine-like products include pahn and agave wines ( Pulque ), maple and tamarind (Indian date) wines, and sake, the Japanese alcoholic drink made from fermented rice, which resembles sherry and is enjoyed as a warm drink. 

The term liquor includes aU liquids, even pure alcohol, which are obtained by fermentation followed by distillation. Some types of liquors contain flavorings. 

Al levels in the cerebrospinal fluid are not always helpful for the diagnosis because even at very low levels (below 10 pg/L) neurotoxic effects can be present [23, 80, 99]. 

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Tertiary butyl alcohol, trimethyl carbinol, tertiary butanol. 2-methyl-2-propanol, Me3COH. Colourless prisms, m.p. 25°C, b.p. 83°C. Prepared by absorbing isobutene (2-methylpropene) in sulphuric acid, neutralizing and steam distilling the liquor. Converted to isobutene by heating with oxalic acid. Potassium-/-buloxide is a very strong base. 

Spirits are described as so many degrees over proof (OP) or under proof (UP). Sometimes, for alcoholic liquors, spirit strength is given in degrees proof, e.g. proof spirit is 100° proof and 70° proof 30° under proof (i.e. a solution eontaining 70% of proof spirit). 

Mesotartaric acid crystallizes in plates (IHjO), m.p. 140 C (anhydrous). Very soluble in water. Obtained from the mother-liquors in the preparation of racemic acid or by oxidation of maleic acid. Potassium hydrogen mesotartrale is soluble in water. 

Through the use of lab tests implemented by the pulp and paper companies in the United States and Canada it was determined that all but one manual technique were both unrepeatable and inaccurate. During some years ago the operators of black liquor recovery boilers have been able to take advantage of the latest teehnology to inspect the wall thickness of the near drum generator tubes. The technology utilises immersion ultrasound and automated computer... 

This reaction is also used on a large scale, to obtain iodine from seaweed. The ash from burnt seaweed ( kelp ) is extracted with water, concentrated, and the salts other than iodides (sulphates and chlorides) crystallise out. The more soluble iodides remain and the liquor is mixed with sulphuric acid and manganese dioxide added the evolved iodine distils off and is condensed. 

A) A solid substance has crystallised from a solution, and it is necessary to separate the crystals (i.e., the solute) from the cold mother-liquor by filtration. 

A) Filtration of crystals from the cold mother-liquor. 

Students are familiar with the general process of recrystallisa-tion from their more elementary inorganic work. Friefly, it consists in first finding a solvent which will dissolve the crude material readily when hot, but only to a small extent when cold. The crude substance is then dissolved in a minimum of the boiling solvent, the solution filtered if necessary to remove any insoluble impurities, and then cooled, when the solute will crystallise out, leaving the greater part of the impurities in solution. The crop of crystals is then filtered off, and the process repeated until the crystals are pure, and all impurities remain in the mother-liquor. 

It is clear that repeated recrystallisation will rapidly leave B entirely in the mother-liquors, and thus provide a pure sample of A. 

When crystallisation is complete, the mixture of crystals and crude mother-liquor is filtered at the pump, again using a Buchner funnel and flask as described on p. 10, and the crystals remaining in the funnel are then pressed well down with a spatula whilst continual suction of the pump is applied, in order to drain the mother-liquor from the crystals as effectively as possible. If it has been found in the preliminary tests that the crystalline material is almost insoluble in the cold solvent, the crystals in the... 

If the mother-liquor from the crude product (together with the washings) is concentrated to nearly half its original volume by gentle distillation, and is then cooled and seeded with a trace of the first crop, a second and less pure crop of the a-methylglucoside is obtained. This should be purified by recrystallisation from the mother-liquor obtained from the recrystallisation of the first crop, and then if necessary recrystallised a second time from a small quantity of fresh methanol. Yield of second crop, about... 

The crude concentrated mother-liquor still contains some... 

The relatively concentrated hydrochloric acid is employed so that with ordinary use of the apparatus, spent liquor does not accumulate very rapidly the concentrated acid also ensures a brisk and delicately controlled flow of gas. When the generator is replenished with acid, marble or both, the de-aeration procedure detailed above is repeated until a sufficiently air-free gas supply is obtained. 

The theory underlying the removal of impurities by crystaUisation may be understood from the following considerations. It is assumed that the impurities are present in comparatively small proportion—usually less than 5 per cent, of the whole. Let the pure substance be denoted by A and the impurities by B, and let the proportion of the latter be assumed to be 5 per cent. In most instances the solubilities of A (SJ and of B (/Sb) are different in a particular solvent the influence of each compound upon the solubility of the other will be neglected. Two cases will arise for an3 particular solvent (i) the impurity is more soluble than the compound which is being purified (/Sg > SA and (ii) the impurity is less soluble than the compound Sg < S ). It is evident that in case (i) several recrystallisations will give a pure sample of A, and B will remain in the mother liquors. Case (ii) can be more clearly illustrated by a specific example. Let us assume that the solubility of A and 5 in a given solvent at the temperature of the laboratory (15°) are 10 g. and 3 g. per 100 ml. of solvent respectively. If 50 g. of the crude material (containing 47 5 g. of A and 2-5 g. of B) are dissolved in 100 ml. of the hot solvent and the solution allowed to cool to 15°, the mother liquor will contain 10 g. of A and 2-5 g. (i.e., the whole) of B 37-5 g. of pure crystals of A will be obtained. 

The technique of the filtration of hot solutions has already been described in Section 11,28. The filtration of cold solutions will now be considered this operation is usually carried out when it is desired to separate a crystalline solid from the mother liquor in which it is suspended. When substantial quantities of a solid are to be handled, a Buchner funnel of convenient size is employed. The ordinary Buchner fimnel (Fig. 11,1, 7, a) consists of a cylindrical porcelain funnel carrying a fixed, flat, perforated porcelain plate. It is fitted by means of a rubber stopper or a good cork into the neck of a thick-walled filtering flask (also termed filter flask, Buchner flask or suction flask) (Fig. 11,1, 7, c), which is connected by means of thick-walled rubber tubing (rubber pressure tubing) to a similar flask or safety bottle, and the latter is attached by rubber pressure tubing to a filter pump the safety bottle or trap is essential since a sudden fall in water pressure may result in the water sucking back. The use of suction renders rapid filtration possihle... 

If the filtrate is of value, it should be transferred to another vessel immediately the crystals have been drained. Frequently, the mother liquor may be con centra ted (suitable precautions being, of course, taken if it is inflammable), and a further crop of crystals obtained. Occasionally, yet another crop may be produced. The crops thus isolated are generally less pure than the first crystals which separate, and should be recrystaUised from fresh solvent the purity is checked by a melting point determination. 

When the volume of mother liquor is large and the amount of crystals small, the apparatus of Fig. II, 32, 1 may be used. The large pear-shaped receiver is supported on a metal ring attached to a stand. When the receiver is about two-thirds fuU, atmospheric pressure is restored by suitably rotating the three-way stopcock the filtrate may then be removed by opening the tap at the lower end. The apparatus is again exhausted and the filtration continued. 

After the main filtrate has been removed, the crystals should be washed in order to remove the mother liquor which, on drying, would contaminate the crystals. The wash liquid will normally be the same solvent as was used for recrystallisation, and must be used in the smallest possible... 

In order to dry the crystals, the Buchner funnel is inverted over two or three thicknesses of drying paper (i.e., coarse-grained, smooth surfaced Alter paper) resting upon a pad of newspaper, and the crystalline cake is removed with the aid of a clean spatula several sheets of drying paper are placed on top and the crystals are pressed flrmly. If the sheets become too soiled by the mother liquor absorbed, the crystals should be transferred to fresh paper. The disadvantage of this method of rapid drying is that the recrystallised product is liable to become contaminated with the Alter paper flbre. 

The apparatus depicted in Fig. 11,34, 1, intended for advanced students, may be used for the filtration of a small quantity of crystals suspended in a solvent either a Hirsch funnel or a glass funnel with Witt filter plate is employed. The mixture of crystals and mother liquor is filtered as usual through the funnel with suction. Rotation of the three-way tap wifi allow air to enter the filter cylinder, thus permitting the mother liquor to be drawn oflF by opening the lower tap. The mother liquor can then be applied for rinsing out the residual crystals in the vessel, and the mixture is again filtered into the cylinder. When all the crystals have been transferred to the funnel and thoroughly drained, the mother liquor may be transferred to another vessel the crystals may then be washed as already described (Section 11,32). 

By inclining the flask A, applying suction at 3 and connecting 1 to a source of inert gas, the mother liquor may be drawn into the sintered glass funnel C without the... 

Sometimes an air bubble enters the tube E and prevents the regular flow of liquid from B the air bubble is easily removed by shaking the rubber tube. The flask A is heated (e.g., by a ring burner) so that distillation proceeds at a rapid rate the process is a continuous one. If the liquid to be steam distilled is lighter than water, the receiver must be modified so that the aqueous liquors are drawn off from the bottom (see Continvmia Extraction of Liquids, Section H, 44). 

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