Alcoholic drinks originated through the action of yeast cells on sugar containing liquids. Alcoholic drinks are aromatic liquids with a specified alcohol content. Some kinds contain carbon dioxide, others a quantity of sugar. They are either fruit/sap based or grain based. They can either be non-distilled or distilled depending on the volume percentage of alcohol per litre. The different types of alcoholic beverages are beer, wine, whiskey, brandy etc. Ethanol content of alcoholic beverages preparation may be quantitatively determined by specific gravity determination. A definite volume of the distillate is collected and its specific gravity determined by pycnometer method. Through suitable use of appropriate tables.

Material and reagents                                       

·         Distilled water

·         Distillation assembly

·         Distillation flask

·         Graduated cylinder

·         Thermometer

·         Pycnometer

·         Analytical balance

·         Anti-forming agent solution

·         Volumetric flask

Procedures

·         Take 100 ml of sample in a 250-ml distillation flask containing about 12.5 ml of distilled water

·         Connect the flask with distillation apparatus, Turn on the instrument and collect 100mL of distillate

·         Allow the distillate to come to room temperature.

·         Carefully clean and rinse pycnometer with distilled water then dry it at 105⁰C.

·         Weigh empty and dry pycnometer and record its weight.

·         Fill the pycnometer with distilled water, Close with stopper then weigh and record its weight

·         Lastly, Weigh the pycnometer filled with the portion of sample distillate and closed with stopper

·          Calculate the specific gravity of the sample with the formula below.

Specific gravity ={Ms -Mp}/{Mw-Mp}\frac{Ms-Mp}{Mw-Mp}

      Where:

                                       Ms: Mass of pycnometer plus sample distillate

                                      Mp: Mass of empty Pycnometer

                                      Mw: Mass of pycnometer with distilled water

 ·         After getting the specific gravity of the sample, the corresponding ethyl alcohol content will be obtained from the table. Click here to get the table

References:

1.      CME Catsberg, G. J. M Kempen and Van Dommelen, Food Hand Book, Alcoholic Drinks  

2.      Indian Food Industry, May-Jun ’03, Vol. 22, No. 3, Category Liquor

3.      Herstein KM. 2007. Chemistry and Technology—Wines and Liquors. Dayton, OH: Herstein Press.

4.       George W.L., William H., official Methods of Analysis of AOAC international, 18th Edition, 2005 ISBN 0-935584-78-1