29/4/2014 Whisky analysis - Whisky: Technology, Production and Marketing - Hotelmule - Hospitality and Tourism Industry Portal

http://www.hotelmule.com/html/01/n-1801-7.html 1/2

Send to friend Last | Next

Return

Whisky analysis - Whisky: Technology, Production and Marketing

Release: Jul 25 2009 00:37 Author: Members View: 28672 times Print

A typical higher alcohol chromatogram for a Scotch blended whisky isshown in Figure 9.1 (using Carbowax1 20M on Carbopak1 B as stationaryphase), and quantitative results for typical Scotch, Irish, bourbon andCanadian whiskies are given in Table 9.2. The results show that Scotchgrain whisky from the continuous Coffey still distillation contains veryfew congeners after isobutanol, while Scotch malt whisky from a doublepot still distillation is much richer in the less volatile congeners that eluteafter isobutanol. The less volatile congeners, particularly 2- and 3-methyl-butanol and above, are eliminated from grain spirit in the rectifier sectionof the Coffey still, and are recovered as fusel oils. Blended Scotch and Irishwhiskies have congener profiles representing the various malt and grainwhiskies used in their blends. Bourbon whiskey is very rich in congeners,as there is little if any rectification in the bourbon distillation processbeyond the beer still, in the doubler. Canadian whiskies, being blends ofmatured grain neutral spirits and a bourbon-style distillate, have relativelylow congener concentrations compared to the other whiskies examined. Ofparticular note are the relatively low methanol concentrations encounteredin all whiskies fermented from cereals (normally < 25 g/100 l abs. alc.) andthe ratios of 3-methylbutanol/2-methylbutanol (typically between 2.5 and3.5). Other trace congeners that may be detected in this analysis alsoinclude n-butanol and acetic acid.Figure 9.1Typical higher alcohol gas chromatogram for a blended Scotch whisky. Peaks 1,

acetaldehyde; 2, methanol; 3, ethyl acetate; 4, propanol; 5, isobutanol; 6, butanol; 7, diethyl acetal; 8, internal standard; 9, 2-methylbutanol; and 10, 3-methylbutanol.

(Aylott et al., 1994, reproduced by permission of the Royal Society of Chemistry.)

Table 9.2

Major volatile congener concentrations (g/100 l abs. alc.) in single samples of Scotch malt, grain and blended whiskies, and Irish,American and Canadian whiskies

29/4/2014 Whisky analysis - Whisky: Technology, Production and Marketing - Hotelmule - Hospitality and Tourism Industry Portal

http://www.hotelmule.com/html/01/n-1801-7.html 2/2

The normal concentration unit used in whisky congener analysis is gramsper 100 litres absolute alcohol (g/100 l abs. alc.). Thus congener concentrationis related to the volume of pure alcohol, and not simply the volume of sampleliquid. This concentration unit at first appears strange, but it proves veryuseful in that it can relate to a whisky that will occur at many different alcoholicstrengths during its manufacturing process. For example, a Scotch grainspirit may be distilled at approximately 94.6 per cent, matured at 65 per cent,and then blended and finally bottled at 40 per cent vol.

197/19|<<567891011121314>>|

-5 -3 -1 - +1 +3 +5

Rate：0

Industries Sites

Health Industry | Finance Industry

Hotelmule | Forum | Site Panel | Site Map | Spaces | Contact Us

Copyright © 2013 Hotelmule All rights reserved

Natural GasChromatograph

envent-eng.com

Measures up to 16 components incl:

hydrocarbons, CO2 , N2 & H2S