R.T. Heath. 1941. The effect of certain distillation procedures on the brandy composition.

First a great thank you to Susan Coppin and the team of archivists at the University of Adelaide who made recovering these documents possible.

All these documents from Australia were contained in Series 600 of the Roseworthy Agricultural College archives.  We should probably figure out how to digitize all of the papers.

Heath, R.T. The effect of certain distillation procedures on the brandy composition. 1941. from Series 600 University of Adelaide Archives, Inventory Identifier 060000012 Box Number 1. [PDF]

“The object of this paper is to see:

1. What effect reflux, as governed by the length of the column has on the resultant brandy fractions, and comparing with reflux obtained by the use of the brandy ball: and to establish:

II. A recheck on the run-back of heads and tails to the next wine charge, as it is still in doubt whether the final brandy is cleaner and or a longer cut in the brandy-run is obtained under this method.”

All of these simple experiments probably need re-performed in conjunction with modern analysis that can sub-divide the congener groups like esters, aldehydes, volatile acids, and higher alcohols.

“A still constructed by Pontifex and Wood similar to the brandy-ball effect, where the whole column up to the bend is cooled by water overflowing from the top tray to one immediately below, and so on down the column — the cooler water therefore being at the top, this being only one of the many types of stills used.” This might be a description of an experimental still used in Armagnac production. I think that Pontifex and Wood were equipment designers.

“and according to Rene et Jean Lafou (16) all heads and tails are run-back to the next wine charge, whereas others state that only part of the feints are returned; some to the brouillis charge, some to the next wine charge, while proportions may be discarded altogether.”

“The tails are sometimes separated into two portions; the first fraction down to 20 percent A.A. returned to the next brouillis, while the second fraction from 20 percent to 0 percent is returned to the next wine charge.”  If this is practiced I suspect the congeners of the second part of the tails will benefit from a longer time under heat and the total acidity of the wine charge to catalyze esterification.  Eventually a tails fraction has to be thrown away because otherwise you could not get rid of accumulated furfural.

“Plan of Experiment.

A study of the resultant brandy fractions after–

(a) Lengthening the column, by raising the arm in upward slope to the condenser.

(b) Using a cool brandy-ball, without lengthening column.

(c) Comparisons of the above made against fractions obtained without the use of either (a) or (b)”

“the Table shows a definite decrease in the acid and ester content both by the Lengthened column and brandy-ball whereas the other constituents remain more or less constant, except perhaps a descrease in secondary alcohols obtained by means of the lengthened column.

Therefore, from the low-wines produced similar effect would be expected to occur in the same constituents in the brandy-fractions, and such is the case.”

Heath goes on to discuss all the congener categories separately.

From his organoleptic analysis, Heath suspects that “the higher alcohols have a very marked effect on the bouquet, more so than esters.”

Heath concludes that lengthening the column is more efficient than employing a brandy-ball.

Next Heath re-explores run-back to verify Angove and Graham’s results.  The recycling of fractions was for some reason barely practiced in Australian brandy making.

[in regards to volatile acids] “it appears that with the use of the feints an equilibrium is established in this constituent which distills over unchanged throughout progressive distillations.”

“As for the other constituents, the esters appear to gradually increase throughout subsequent distillations, while aldehydes decrease slightly. Secondary alcohols and Furfural, however, have undergone little or no change whatever with the use of the feints.”

“Esters: Here it is interesting to note that although the low wines gradually increase in ester content, produced by the effect of run-back, this increase is not uniformly distributed among the brandy fractions, but in each case more are pushed into 1st. heads and 2nd tails, leaving the fractions 2nd heads, brandy and 1st tails uniform within themselves.”

“The course taken by the esters is to concentrate in heads and tails with decreasing amounts in towards brandy.”

“Results obtained in the above experiment also show that feints play an important part. It does not necessarily mean that by introducing the dirty or undesirable fraction of the brandy-run to the following brandy charge a corresponding dirtier spirit will result; but on the contrary, it cleanses all fractions of their respective constituents except perhaps esters which tend to increase gradually-this being an advantage to Australian brandies as they are generally low in ester content, as compared with French standards. Consequently, by utilizing the feints it is evident that a longer run on brandy could be obtained than otherwise.”  So it can be said that recycling fractions increases the size of the hearts fraction while at the same time it recycles fatty acids which gives more opportunity to produce esters.

Unique entries in the bibliography:

“2. Nettleton, J.A. “Manufacture of Spirit”. 123-150.”

This text has a few editions with the earliest being 1893. Sadly it hasn’t been digitized by google yet or republished and used copies are astoundingly expensive.  Ian Buxton, the rare book collector/re-publisher made a limited edition high end reproduction of the text. I bought one and he has a few left for about $150USD.

Apparently the wisdom of this book plays a small part in the birth of Japanese Single Malts.  The young Japanese chemist Masataka Taketsuru had tracked down the author with discouraging results when he visited Scotland in 1919.

Apparently Masataka returned to Japan with a Scottish wife.  It is a really wonderful story.

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