Alcohol content

The alcohol is determined either by distilling the wine and calculating from tables the alcoholic content of the distillate from its specific gravity at 150 C. or by means of a special apparatus known by the name of ebullio-scope. This gives the alcoholic degree of the wine with sweet wines, a calculation is sometimes also made of the potential alcoholic strength, which is the sum of the alcohol found and of that derivable from the fermentation of the sugars still present.1 

If the wine is highly alcoholic, it is convenient first of all to dilute it with water to double its volume. 

With an acid wine, it is well to prevent distillation of the volatile acids by neutralising the acidity with magnesium oxide or a few drops of concentrated caustic soda solution. Frothing is prevented by leaving the wine slightly add or by addition of tannin. 

Mainland s Ebullioscope.—This is based on the principle that aqueous alcoholic mixtures boil at temperatures which are more or less low compared with that of water in accordance with their alcoholic content. The apparatus (Fig. 50) consists of a small conical metallic boiler C, 

The procedure is as follows Water is introduced into the boiler up to a certain level marked inside, the depth of water being insufficient to immerse the thermometer bulb. The cover is then screwed on, the condenser filled with cold water and the lamp lighted. When the extremity of the mercury column fails to move any further, the scale, which is graduated from 0 to 25, is adjusted so that the zero corresponds with the meniscus of the mercury column and fixed in this position by means of a screw. The zero should be determined for each test, or for each series of tests at least, since it varies with the atmospheric pressure. 

---

Estimate the interfacial tension gradient formed in alcohol-water mixtures as a function of alcohol content. Determine the minimum alcohol content necessary to form wine tears on a vertical glass wall [174] (experimental veriflcation is possible). 

Finally the influence of the temperature and addition of ethanol on the enantioselectivity of the Diels-Alder reaction was studied. Table 3.3 summarises the results for different aqueous media. Apparently, changes in temperature as well as the presence of varying amounts of ethanol have only a modest influence on the selectivity of the Cu(tryptophan)-catalysed Diels-Alder reaction in aqueous solution. However, reaction times tend to increase significantly at lower temperatures. Also increasing the alcohol content induces an increase of the reaction times. 

In enzymes, this folding process is crucial to their activity as catalysts, with part of the structure as the center of reactivity. Heating enzymes (or other treatments) destroys their three-dimensional structure so stops further action. For example, in winemaking, the rising alcohol content eventually denatures the enzymes responsible for turning sugar into alcohol, and fermentation stops. 

Compositional aspects that are regulated include a label statement within 1.5% for table wine (for dessert wines, 1.0%) of the wine s alcohol content. Eor tax identity reasons, alcohol of 7—14% is required for table wines and 17—21% for dessert and appetizer wines. Eederal excise tax rates are 0.28/L for table wines, 0.41/L for wines 14—21% alcohol, and 0.83/L for those (rare) >21-24%. Coolers made with wine become taxable at 0.5% and are taxed as table wine above 7% alcohol. Sparkling wine is taxed at 0.90/L and carbonated at 0.87/L. The borderline to incur these taxes is CO2 above 3.92 g/L. 

Many commercial grades of pine oil are available and are specified by physical properties and total alcohol content. Some commercial pine oils and the typical physical properties are Hsted in Table 4. Other grades of pine oil may constitute a blend of synthetic and natural pine oil and give the product a different odor characteristic. The odor difference is caused by the presence of phenoHc ethers anethole and methyl chavicol. 

The thermal glass-transition temperatures of poly(vinyl acetal)s can be determined by dynamic mechanical analysis, differential scanning calorimetry, and nmr techniques (31). The thermal glass-transition temperature of poly(vinyl acetal) resins prepared from aliphatic aldehydes can be estimated from empirical relationships such as equation 1 where OH and OAc are the weight percent of vinyl alcohol and vinyl acetate units and C is the number of carbons in the chain derived from the aldehyde. The symbols with subscripts are the corresponding values for a standard (s) resin with known parameters (32). The formula accurately predicts that resin T increases as vinyl alcohol content increases, and decreases as vinyl acetate content and aldehyde carbon chain length increases. 

Commercially available PVB resias are generally soluble in lower molecular weight alcohols, glycol ethers, and certain mixtures of polar and nonpolar solvents. A representative Hst is found in Table 5. Grades with lower vinyl alcohol content are soluble in a wider variety of solvents. A common solvent for all of the Butvar resins is a combination of 60 parts of toluene and 40 parts of ethanol (95%) by weight. 

Many grades of interlayer are produced to meet specific length, width, adhesion, stiffness, surface roughness, color (93,94), and other requirements of the laminator and end use. Sheet can be suppHed with vinyl alcohol content from 15 to about 23 wt %, depending on the suppHer and appHcation. A common interlayer thickness for automobile windshields is 0.76 mm, but interlayer used for architectural or aircraft glaring appHcations, for example, may be much thinner or thicker. There are also special grades to bond rear-view mirrors to windshields (95,96) and to adhere the components of solar cells (97,98). Multilayer coextmded sheet, each component of which provides a separate property not possible in monolithic sheet, can also be made (99—101). 

A complete survey of the different types of beer with which one might be confronted during a worldwide trip is almost impossible. Various conditions such as tradition, taxation, and other peculiarities have resulted in the beet market of today, ie, numerous types varying in strength, color, alcohol content, and bitterness. 

Dortmund. Dortmund is a pale beer with fewer hops than Pilsner but mote body and taste. The alcohol content is 3.9—4.7% by vol and storage time is 3—4 months. The brewing water is hard and contains large amounts of carbonates, sulfates, and chlorides. 

Others. The only top-fermented beer ia Scandinavia is Hvidt Lp. it has a low alcohol content (2.6% vol), a high level of extract, and is very mildly hopped. Smoke Beer is manufactured ia Germany and Denmark. It is made entirely from malt that is dried by direct beechwood fumes. In Denmark it is called Skibs Lp. (Ships Beer) and for centuries was iatended for consumption ia the Danish Navy and Marines siace it had better keeping quahties than the ordinary beers. It is top-fermented with low alcohoHc content. 

A beer with normal alcohol content, but much lower ia caloric coateat, can be made with the help of external, specific enzymes that ate added duriag mashing or fermentation to achieve further breakdowa of carbohydrates. 

Fermentation is carded out in two different, very distinct ways top fermentation and bottom fermentation. The governing principles are the same in both processes the chief differences are in the type of yeast and temperature employed, and consequently the method used for collecting the yeast after fermentation is finished. The alcohol content and, to a higher degree, the taste and stabiUty of the beer, are directly dependent on the normal progress of the fermentation. 

The beers in Table 11, with the exception of lunch beer, have an original gravity of 6.4—8.1°P. The alcohol content is 0.65—3.4% vol the remaining extract is 3.9—7.1°P. Since the aroma of beers is obtained mainly during fermentation, beers having Htde or no alcohol produced with no or intermpted fermentation are lacking in "tme" beer aroma. Previously aroma was improved through addition of small amounts of yeast (2—10 mg/L) to the unfermented beer. The addition usually takes place just prior to filtration. 

U.S. regulations define this standard as foUows proof spirit shaU be held to be that alcohoHc Hquor which contains one-half its volume of alcohol of a specific gravity of 0.7939 at 15.6°C ie, the figure for proof is always twice the percent alcohol content by volume. For example, 100° proof means 50% alcohol by volume. In the United Kingdom as weU as Canada, proof spirit is such that at 10.6°C alcohol weighs exactiy twelve-thirteenths of the weight of an equal bulk of distiUed water. A proof of 87.7° indicates an alcohol concentration of 50%. A conversion factor of 1.142 can be used to change British proof to U.S. proof. 

Distilled spirits are governed by the Bureau of Alcohol, Tobacco, and Firearms regulations. Every botde of distilled spirits must contain a specified percent of alcohol or proof as stated on the label. Proof is the ethyl alcohol content of a Hquid at 15.6°C, stated as twice the percent of ethyl alcohol by volume. 

The proof content is determined by the use of a standardized hydrometer with a standardized thermometer. The alcohol content can also be determined by the use of an immersion refractometer, a pycnometer, or a density meter. 

The actual proof must not be more than the stated proof or no less than 0.3 below the stated proof for soflds less than 600 mg/100 mL, and no less than 0.5 below the stated proof for soflds greater than 600 mg/100 mL. The actual alcohol content must be given to the nearest 0.5%. 

Poly(ethylene-i (9-vinyl alcohol) is made by saponification of ethylene—vinyl acetate copolymers. The properties of these materials depend on the amount of vinyl alcohol present in the copolymer. High vinyl alcohol content results in more hydrophilic materials possessing higher densities, stiffness, and moduh. They are used commercially as barrier resins for packaging. Important producers include Du Pont and EVALCA (74) (see Barrier polymers). 

The deterrnination of the proof (the alcohol content) is us uaHy made by measuring specific gravity with hydrometers at the standard temperature of ... 

Table I4.P shows the influence of these variables on some properties. The residual hydroxyl content is expressed in terms of poly(vinyl alcohol) content and residual acetate in terms of poly(vinyl acetate) content.

For reasons explained below, the effect of increasing the vinyl alcohol content in EVOH is quite different to that of increasing the vinyl acetate content in EVA. In the case of ethylene-vinyl acetate (EVA) copolymers, increasing the vinyl acetate content up to about 50% makes the materials less crystalline and progressively more flexible and then rubbery. In the range 40-70% vinyl acetate content the materials are amorphous and rubbery, whilst above 70% the copolymers become increasingly rigid and brittle. 

Commerical grades of EVOH typically have vinyl alcohol contents in the range 56-71%, but in contrast to the corresponding EVA materials these copolymers are crystalline. Furthermore, an increase in the vinyl alcohol content results in an increase in such properties as crystalline melting point, tensile strength and tensile modulus together with a decrease in oxygen permeability. This is a reflection of the fact that the ethylene and vinyl alcohol units in the chain are essentially isomorphous (see Sections 4.4 and 14.3.1). 

As is to be expected, the table shows that as the humidity is increased, causing swelling and an increase in the interchain separation, so the oxygen permeability increases. Also, as expected, the percentage increase is greater the higher the vinyl alcohol content. 

The filtered dough is then returned to a mixer and the alcohol content reduced to 25% by kneading under vacuum. Further reduction in the alcohol content is brought about by rolling the compound on a hooded two-roll mill. The milled product is then consolidated on a two-bowl calender and sheeted off in hides about j in thick. At this stage the solvent content is between 12 and 16%. 

---