Variations in quality of new make spirit
When you distil, you aim for consistency of distillation. So the first thing to check was whether the sample taken was indeed representative. Fortunately it turned out not to be so. The alcohol distilled in the spirit still is usually a mixture of Low Wines (22%abv ) from the Wash Still and the Heads and Tails, the beginning and end of the spirit run. These are the Foreshots (72%abv) and the Feints from 63% down to 1%abv
When we distil at Bladnoch it's usually a lorry load of malt at a time which is 28 tonnes divided into 5 tonne mashes. Because of our low level of production we are often silent for long periods. When you finish a production run you will always have a quantity of foreshots and feints left over from the previous distillation . We don't wish to have an excessive amount of alcohol in the Low wines and Feints Charger because it evapourates in the tank. If you visit a silent distillery you usually can smell alcohol from the stillhouse (and from the warehouses) This is "money" escaping. I can leave spirit in the stainless steel receiver and go back in a month and find that both volume and strength are considerably reduced, much more so than in a cask.
When we restart production the first distillation is likely to have only a small proportion of Low Wines and the resulting spirit can be poorly balanced. Usually at Bladnoch it is mixed in the filling store with the next five or six distillations before being filled in a cask.
In the case of the sample it had been taken from the first run after we re-started production.