Modérateur : Modérateurs
We filled about 37 casks, ten at the strength it had been pumped up to the filling store at (70.8%) twenty at our normal filling strength 63.5% abv and seven at a reduced strength of 58% abv.
You never end a filling by managing to have the exact amount in the tank to fill a barrel. So the last (partially filled cask) is weighed and left in the warehouse to be filled next time. It's known as the Stock Cask and distilleries used to have a special lock up room for it. So our stock cask is sitting with a small amount of spirit at 58% and our next filling will be at 63.5% giving me a small problem of documenting accurately the final strength and volume in this cask.
Those of you who are observant and interested in the minutia might also realise that when we change cask filling strengths any alcohol that is in the pipes between the pump and the filling head will be at the strength of the previous cask.
Two and a Half Times Distillation
I said last night that we were going to distil the Low Wines in the spirit still and instead of separating Foreshots, Middle Cut, and Feints we would distil it all as one and the resulting spirit would then be distilled with the next batch of Low Wines. Effectively the first batch will have passed through the wash still and the spirit still and then the spirit still again (ie three distillations) and the second batch will be distilled twice as normal. This is usually what's known as a two and a half times distillation.
Today's distillation in the Spirit Still began with a charge of Low Wines/Feints of about 9536 litres at about 26.5%litres (2527 litres); it came into the safe at about 74%, ran for about six and a quarter hours down to 1%. This produced about 5500 litres at an average of 45.6%. (2508 litres of alcohol)
On Monday we will add the above 5500 bulk litres to the contents of the Low Wines and Feints Charger (5987 litres at 22.1% ie. 1323 litres. This is all Low Wines and is slightly weaker than the normal strength of 26% to 27% shown above because it contained none of the strong foreshot or weaker feints) So the approximate ratio will be 2 to 1 between alcohol which will have been distilled 3 times and alcohol which will have been distilled twice.
If you have read this far you must be as crazy as me.
So I'll leave you to guess what sort of strength our final distillation will end up at.
Also cleaned the Wash Still today. This involves getting inside in a chemical resistant suit and painting caustic on the inside of the copper leaving it for half an hour to soften and then power hosing it off. It's spotless but I need to do the same with the spirit safe just to give the spirit every chance.
"We started off with about 3831 litres of pure alcohol. This was held in two tanks. The Low Wines and Feints Charger held 5987 litres @ 22.1%abv (1323 la) This had been distilled once.
In the Low wines and Feints Receiver was 5500 @45.6%abv (ie 2508 la) This had been distilled twice. Total bulk volume 11487 litres which is slightly more than the 10000 litre capacity of our spirit still.
I wasn't sure what strength the spirit would enter the safe at, bearing in mind that the average strength of this charge was about 32.8%compared to a more usual 26%/27% during normal distillation. It would normally come in to the safe at about 73/74% but in the two and a half times distillation it entered at 78.5.% This was slightly less than I guessed but I was relieved because our hydrometers only covered the range 50/80. So when we ran it down to our cut point 63.5% the average strength of spirit was 72.5% rather than the usual 69.5%/70
So we ended the distillation with about 2221 litres of new make spirit at 72.5 and 5806 litres of feints at a significantly higher than normal 38.6% There may be a slight inaccuracy in these figures due to the difference in calibration of the two tanks. In other words you can dip the feints receiver and the tables say 6000 litres but when you pump it up to the charger and dip it there the tables may say 5900. Obviously the pipes hold some, but you could just as easily appear to have more than you started with. So much for accuracy. The callibration of tanks is not always an exact science.
More significant was the taste I haven't worked out yet how long in total this spirit has been in the copper but it's quite a long time. The taste even at a strength of over 70% seems to me to be very fine. You can hold it on your tongue without being nipped for as long as you wish and it keeps giving off taste. I hope in about 10 years time it will be very good. I'm going to keep it for my old age.
The only thing I have to decide is the strength at which to fill it. Certainly a few casks at full strength (72.5), and also our standard 63.5 but if I filled at a really low strength say 55% would I be taking too big a risk?
All you wizz kids. Risk committing yourself to an answer!
If i understand it all, for me filling at low strenght , there is little risk of not having the 40° after X years.
It depends of the cask quality of course, and where you old it, but also if you want to keep the cask for a long time, and if you want to "make" single cask bottling.
I am also interested whith your answer at Laphroaig question?
With regard to filling at different strengths, obviously you save on wood costs and storage costs when you fill at higher strength, ie you are maturing whisky not water.
Having said that one of the nicest Bladnochs that I have tasted was 12 years old and had been filled at 57% and had evapourated to 51%. We usually fill at 63/64%
If you guage any batch of say 50 casks at say 12 years , there will be a wide range in terms of volume and a wide range of strengths. Some casks are particularly tight and dense and evapourate very little but the whisky can be sharp. The variation in loss of alcohol is the reason we tend to buy by reguaged litres on anything over 12 years of age. It is not pleasant to buy a cask priced on the basis of original litres of alcohol (ola) and find it two thirds empty due to leakage. If you are buying 50, the lower price per litre based on ola's may make it worth while, you may be lucky, but it some people would say that it usually averages out the same. Personally I always prefer to buy on the basis of ola's
For example on a 12 year old you might pay £6.50 per litre based on what was originally filled into the cask, a barrel originally filled with 190 bulk litres at 63.5% will have originally contained 120.65 litres of alcohol, so the cask will probably cost you £784.00 If you buy it reguaged it will probably cost £1.10 per litre for every year of it's age which at 12yo (assuming 25% evaporation)will probably contain 90 litres x 12 x£1.10 £1188, but some of the 50 casks may have leaked.
The above figures are trade figures.
I agree with you on the influence of the cask quality and on where you hold it and for how long you wish to age it.
Generally Lowland whiskies tend to be sold younger. Bladnoch and Rosebank ceased production in 1993, so all our whisky is over 12 Distilling only re-commenced in 2000
Bladnoch is situated at sea level and the amount of annual evapouration is greater than at Tomatin where the warehouses are much colder in winter.
From another point of view, the University of Montpellier is talling that the ideal strength for vanilin extraction from the wood is 50%. I guess that the closer to 50% your maturatin strength will be, the higher vanilin content will come in your whisky. But that probably depends on the type of wood you use (new or refilled, sherry or not, etc...).
Hope this can be of help to you.
Thank you very much for those descriptions and explanations in terms of producing & housing, but also for the trading approach...
Do not hesitate to teach us more ;)