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Here we have another lost reference from the bibliography of Kervegant’s Rhum and Cane Eau-de-vie. Nothing too monumental, but interesting to skim. My favorite part is where plantain leaf flags are placed between the staves to create a seal. I doubt that is done any more. But it only had to last long enough to make it to the London docks!
I cannot quite figure out how “grogged” puncheons work. I think it may be an excise detail because if the cask is emptied of rum and then filled with water, that water will draw out some of the rum. Now if you fill it up again with rum, there will be a different allowance for absorption in the wood. Thrifty customers used to take the casks they receive, empty them, then fill them with water to draw out more alcohol before returning them. This water would likely be used for eventual blending. Supposedly there was penalties for the practice.
CLEARE (L.D.) — Damage caused to rum puncheons by boring beetles. Agr. J. British Guiana IX, 237-245, 1938.
DAMAGE CAUSED TO RUM PUNCHEONS BY BORING BEETLES.
BY
L. D. CLEARE,
Entomologist,
Department of Agriculture, British Guiana.
I. Introduction.
II. Damage to new staves
III. Damage to ‘grogged’ puncheons,
IV. Examination of damaged staves.
(a) Staves from puncheons in
the Colony.
(b) Staves from puncheons returned
from London.
V Dunnage wood.
VI. Conclusions and recommendations.
I. Introduction.
The investigation dealt with here was undertaken between November 1937 and January 1938 and was the direct outcome of a complaint received of damage by boring beetles to the puncheons of a shipment of rum made to London from British Guiana in August 1937.
The shipment of rum concerned comprised 141 puncheons from two sugar factories and was reported as having, on arrival at London, 76 puncheons (54 per cent.) bored by beetles so that repairs were necessary to the puncheons in London. The report showed that in the 76 puncheons there were 173 bored staves.
The puncheons were made at Georgetown, the staves being imported from the United States of America.
From the first it was evident that there might be difficulty in forming a definite opinion as to where the damage to the puncheons in question had taken place, for it was possible that the attack might have occurred at many points between the receipt of the staves at Georgetown and the final arrival of the packages in London. This was further added to by the absence, at the beginning, of the damaged puncheons so that a more extensive enquiry had to be undertaken than perhaps would have been necessary otherwise.
II. Damage to New Staves.
An, examination was made first of new staves, and stacks of staves at the cooperage wharf at Georgetown of varying dates of arrival were examined, while on 9th November a new shipment of headers was received and these latter were examined both at the time of their arrival and also a few days afterwards.
At the outset it must be stated that both such staves and headers showed damage which was evidently the result of beetle attacks, and judging from the borings in the wood had been caused by probably at least three different species of insects. In spite of this no boring beetles were found and it was evident that
the damage had occurred some time previously.
This damage was not excessive and amounted to 6.7 per cent, over the three lots examined. The details of these examinations are as under :
[Data corrupt. All the data tables are illegible due to how the document was digitized with a lot of OCR related typos throughout.]
Lot No.
Date of examination
Material
Ex hip.
No. examined
No. bored
Percent bored
The damage in both staves and headers was usually quite noticeable and in many instances it was obvious that should such material be used in packages it would cause leakage.
In staves with the smallest sized holes it was not apparent at first whether these were capable of causing leakage. Careful examinations were made, therefore, of a number of these borings by splitting and sectioning the staves, and in several instances it was found that even these holes of small diameter had gone through the staves.
In the headers the damage, usually a larger-sized hole, invariably took the form of an oblique boring at the edge of the particular piece of wood, and here again it was obvious that should such material be built into a package there was likelihood of leakage resulting therefrom.
III. Damage to “Grogged” Puncheons.*
It has long been known amongst coopers in the Colony that puncheons which have been “skipped” and “grogged” when stored for a time, either before or after being repaired, develop “worms” which will in time cause leaks, and these worms may occur to such an extent as to cause the package to be discarded.
The staves of these packages in the course of their storage with rum prior to skipping become soaked with the liquor, and in spite of the grogging still retain some of the alcohol in the wood. When water is placed in these puncheons subsequently some of this alcohol is drawn from the wood, a fermentation is set up and beetles are attracted.
Samples of water from grogged puncheons both at the Colonial Bond and at the cooperage were obtained and the alcoholic content determined. The figures in this connexion are given in Table I.
Whenever puncheons have been in bond for some time defects in the puncheons such as broken staves necessitate a certain number of the packages being changed, the rum being transferred to other puncheons; this process is known as “skipping”.
“Skipping” having taken place the old package is then “grogged” i.e. water put in and retained for a period and then thrown away.
Table I.— Alcoholic Content of Water from Grogged Puncheons
[Missing table.]
A few such “grogged” puncheons were examined, and by carefully sectioning staves from one of these infested puncheons some of the beetles which were attacking them were secured. These beetles proved on examination to be a species of Xyleborus, which genus is well known as wood borers.
The attack in such puncheons often occurs in the headers or around the groove where the header fits into the staves, but also in the staves themselves about the central area where the puncheon comes in contact with the ground when stored on its side. In most instances seen where the attack occurred about the center of the stave it could be associated with some injury to the stave, sometimes only a small indentation, which had allowed ingress of the beetle.
When the damage occurs in the headers, or in their immediate vicinity, the groove, a leak is readily formed, as may also occur if the damage is between two staves. When a stave is penetrated directly, however, the entrance of the beetle in itself may not result in leakage, for in such instances, the beetle, or its larva, does not penetrate beyond a point in the wood where it becomes more or less soaked with the contained spirit. Under such conditions, where leakage occurs it is invariably associated with cracks in the wood often brought about by extreme heating, and the resulting burning and cracking, in the process of making the puncheon.
IV. Examination of Staves from Damaged Puncheons.
A number of staves removed from puncheons which showed beetle borings were examined comprising (a) staves from puncheons in the Colony and (b) staves from puncheons returned from London around which this enquiry started. These will be dealt with separately.
(a) Staves from puncheons in the Colony. A number of puncheons which had been shipped to a plantation from the cooperage in the latter part of November, were reported on arrival at the factory to be bored, and later when the damaged staves from these puncheons were removed and returned to Georgetown they were examined.
These puncheons were made at Georgetown in October and shipped from Georgetown between the 27th and 29th October, and on 6th or 7th November, while at the sugar factory, they were observed to be bored. The shipment comprised 100 puncheons, and 30 of these showed “worm holes” in some of their staves, Twenty-eight of these damaged staves, and three header-pieces were received at Georgetown on 15th December, sent to this laboratory on the following day, and examined on 17th December. Of these staves eighteen were found to be damaged sufficiently to cause leakage, it is believed, and, in ten staves, it was not possible to be certain whether the damage was of such a nature as to cause leakage.
The detailed results of this examination are given in Table II.
Table II.— Examination of Damaged Staves from Puncheons
Ex-shipment of 27th/29th October, 1937.
Group.
Number of Holes.
Outer side of staves only
Inner side only
Extending through staves
Total
Plugged
Not plugged
A staves damage in which would cause leakage
[Missing data due to OCR problems.]
All of this damage had evidently occurred some time previously, and, in some instances at least, before the packages were constructed and was the same as that occurring in new imported staves.
(b) Staves from puncheons returned from London. Late in December six puncheons were received at Georgetown from London which puncheons were stated to be part of the consignment complained about and to be damaged by beetle borers.
On arrival these puncheons were seen and beetle borings were quite apparent in all, even on very cursory examination.
At a later date, careful examinations of these packages were carried out, and the results of the examinations are given below.
The marks on these puncheons showed that they were the product of two cooperages in Georgetown, and were as follows :
In Group A of a total of 121 holes, 22 were situated under the bands of the puncheons, of which 10 had been plugged and 3 not plugged.
In Group B of the 16 holes showing on the outer side of the staves, 6 were only surface holes and had been plugged.
Puncheon
Estate Marks (Stencilled on top)
Colonial Bond Marks (scribed)
Colonial Bond Details
Racked into 3 puncheons
[Missing data table.]
Both the Colonial Bond and the estate marks on the packages showed that only one of the six packages contained 1937 rum. The other five contained either 1935 or 1936 rum. Although the package “C” contained 1936 rum. the liquor was placed in it only in July 1937, but the package itself was evidently constructed in 1935 and had apparently been used at some time previously to the occasion of the last shipment. All the packages, with the possible exception of “C,” had been in the Colonial Bond for some time prior to shipment, one since February 1935 (B), another since April 1935 (D) and a third since October 1936 (A).
The borings in these puncheons were located almost entirely towards the ends of the puncheons, that is, where the puncheons tapered and not about the middle and greatest girth, and staves in all positions in the puncheons were found to be bored.
Further examination of the borings themselves showed that the majority did not extend for any depth into the staves and in fact many were only surface borings. Those which penetrated the staves did so always across the grain of the wood and often in a diagonal direction coming out on the sides of the staves where they were in contact with the adjacent staves, and invariably did not go beyond a point in the wood where it became sodden with the contained alcohol. Some of the boring commenced at a point where two staves abutted and where
there was a slight indentation which allowed ingress of the beetle.
In two instances at least when a puncheon was broken down it was observed that between two staves there still existed the “ flag” (made of the fibre from plantain pseudostem) which had been placed there in the coopering of the package in order to make a tight joint. And what was especially important was that those “flags” had been penetrated by beetle borings.
No such borings of the “flags” could have existed before they were put in place in the packages and the fact that the borings of the flags and of the staves coincided and were identical in every respect left no doubt of their having occurred at a later date.
In another instance there was found a hoop to which wood fibres were adhering, and the area of the staves immediately adjacent to this was severely bored.
A very careful and detailed examination was made then of a number of individual, staves, and dissection of boring carried out. Staves from each of the five puncheons were thus examined. In this way, in staves from each package beetles were obtained which had died in their borings and which on examination proved to belong to the genus Xyleborus.
As regards these puncheons from London then the facts pointed to the damage having occurred after the filling of the packages and also after their removal from the Colonial Bond, and indeed, suggested that the damage had occurred in transit.
V. Dunnage Wood.
Suspicion fell upon the dunnage wood used in storing the puncheons on shipboard. Accordingly, a stack of this dunnage in the vicinity of the cooperage and shipping wharf was examined.
This dunnage is comprised of a miscellaneous collection of local wood, among which examples of Congo Pump, ( Cecropia spp.) Hog Plum (Spondias Monbin L.) and Shirona, (Nectandra spp.) were seen.
Ample evidence was soon obtained that some of this wood was severely attacked by beetles, and further examination disclosed that beetles of the genus Xyleborus constituted the majority of these insects.
In this material the Xyleborus attack was at the time of my examination still active and there was little difficulty of obtaining live beetles although it was evident that the stack had been in position for some weeks.
VI, Conclusions and Recommendations.
From what has been stated above under the different sections it will be seen that beetle damage as found in the present investigation falls into two distinct categories, namely (I) that occurring in new staves, and (II) that occurring in puncheons in one form or another.
(I) Damage occurring in new staves. Little need be said as regards this. It has been stated already that it is the result of beetle attacks before the arrival of the stave in the Colony, and probably occurred at the point of logging operations. Sufficient it is not active when the staves are received in British Guiana, and as the percentage of staves damaged is not high the allowance made by the suppliers (1,200 staves are given per mille rate) is ample to allow for rejections arising from this cause. Incorporation of staves damaged in this manner into puncheons, as previously pointed out, would in many instances cause leakage.
(II) Damage occurring in puncheons. In grogged puncheons which were in storage and in the puncheons returned from London, as has been stated previously, Xyleborus beetles were found to be the cause of the damage.
Beetles of the genus Xyleborus are well known as timber borers in different parts of the world. On account of their habit of feeding on certain fungi which grow in the tunnels which they make in the wood an essential for their existence is that the wood which they bore must be at least moist, and conversely one of the characteristics of these beetles is that they do not attack dried and seasoned wood.
Accordingly, normally it would not be expected that these beetles would attack rum puncheons. If, however, the exterior of a puncheon, either empty, partly filled with weak alcoholic solution or even with rum itself, is wet for some time, or comes in direct with some substance itself more or less wet over a period of time long enough to allow the wood of the puncheon to take up moisture such a puncheon might be attacked by Xyleborus beetles.
The damage caused to grogged puncheons was not investigated in the present instance beyond the point of establishing such damage and ascertaining the insect concerned.
As regards the puncheons returned from London, the fact that the attack was not seen when it first occurred and in an active state, and that several weeks had elapsed before the packages were examined, any conclusions arrived at in this connection must necessarily be of a circumstantial nature.
With this reservation then, it may be said that as the result of investigations and the conditions observed, and the examinations made of the puncheons, there is reason to believe that the damage to these puncheons occurred after the packages were removed from the Colonial Bond, and in all probability while they were in transit to London. Further, that such damage was caused by Xyleborus beetles (Xyleborus badius Eich. Det. K. E. Schedl, through Imperial Institute of Entomology, London) some of which were found in the borings in the puncheons; that such beetles were breeding in all probability in the dunnage wood used with this shipment of rum and that the puncheons were infested and damaged by such beetles.
The measures to be adopted with regard to damage to puncheons in transit and arising from the dunnage wood is, of course, a change in the material used as dunnage. In this connection, it was suggested that perhaps wallaba (Eperua spp.) “ton-wood” might be used instead of the present miscellaneous “cord-wood.” This is not recommenced as the sapwood of wallaba also has been observed to be attacked by several species of Xyleborus beetles.
Beetle bore is still a problem in the wine industry in certain regions. As the article says, the beetles will not attack full spirit casks due high alcohol concentration but they will go after empties in moist storage conditions. The use of chestnut or softer-than-oak wood hoops is partially a way to combat this, as the beetles prefer to bore that over oak. A neighboring winery to me has a big problem with it and has to seal up wormholes with doweling/toothpicks every season.
Flagging is supposed to be used in a way that it doesn’t contact the liquid (moisture causes it to swell which pushes the oak together to better seal), the traditional flagging is basically cattails but I suppose other things might be used by the resourceful cooper.
Grogging is similar to making ‘swish’ (or Jim Beam’s Devils Cut whiskey), using a bit of hot water or steam to extract the residual alcoholic liquid absorbed by the staves. The steam forces into the staves and then when it cools creates a vacuum that sucks the liquid back out. It was an excise dodge because the barrels could be sold ’empty’ and then the liquid extracted by another party with no paper-trail / excise obligation. It was common in areas around the Bourbon industry from when there was much less demand for used bourbon casks (there is an amazing image of a swish still made from a series of a dozen discarded bourbon barrels in https://www.mitchellspublications.com/ur/va/carrjess/tsop/#:~:text=The%20Second%20Oldest%20Profession%20is,to%20the%20present%20day%20of ) Once they have been swished/grogged they are likely to mold unless promptly filled back up or filled with storage solution/so2 which is why the article says there were discarded (so2 can be dangerous with spirit casks though which have been known to explode if there is still residual alcohol vapor).