REFINED VICES

Daily Record wrote: Jul 14 2008 By Donna Watson

WHISKY experts have come up with a way to save the angel's share escaping from their barrels - wrapping them in cling film.

At least two per cent of each cask evaporates through the oak after the distilling process. The industry say it goes "to the angels".

But drinks giants Diageo have shown that using plastic wrap to cover each barrel could stop it - and save them gallons of whisky.

The company - makers of malts such as Talisker, Lagavulin and Glenkinchie as well as a number of popular blends - could increase their profits by millions each year.

The angel's share costs a fortune but distillers won't change the cask because of the flavour the oak gives their product.

The cling film results are said to have "astounded" scientists at the distilleries. It is not thought to affect the taste of the whisky.

A Diageo spokesman said: "At this stage, the technologies under trial are not proven and we are continuing our research."

Source: Daily Record

I'm fascinated by this story - would it work?

I know when we were in Jamaica we were discussing alternative ageing techniques with the production team including stainless steel vats but with the wood inside so there was still the interaction - supposedly this does not work...

I wonder how much of it is just a general reluctance to change their ways?

I'm not expert when it comes to this angel's share business but assuming the barrel is wrapped in plastic, wouldn't the angel's share just get stuck between the plastic and the barrel? Or does the wood then suck it back in? Perhaps a more logical solution is to collect the "dew", but is it then put back in the barrel or stored somewhere else?

It would possibly be stored somewhere for use in the next batch.

My first impression - and please correct me if I'm wrong - is that barrel exposure to the air (read that again) is a two-way street, with alcohol being lost (the Angel's share) while oxygen/air passes in! Keep in mind that one of the most important factors in barrel/oak aging is oxidation of alcohols and other components in an interactive maturation process. Cutting off the oxygen might well have the same effect as it does with my patients, lol...

For those who don't mind my long winded style, here's yet another length discussion of oaking and maturation (Link). Enjoy.

Obsession, obsession!

When I am faced with a new subject or interesting questions, I find it hard to let things lie and usually find myself researching once again. And so it went for this notion of - god help us - cling wrap. After much research the answers became clear (pun intended). Allow me to summarize:

1. Even the tightest grain oak barrels, well built and sealed are permeable (both ways) via (a) porosity and (b) the oak acting as an osmotic membrane.

2. Alcohol and water pass out, creating a vacumn. At first the barrel - particularly the ends - deflect and prevent open space above the product. This takes about three weeks.

3. The vacumn draws in outside air, but a very small vacumn always remains. Nonetheless oxygen necessary for successful oxidation and aging is indeed drawn in. About 20 cc/liter/year of air is drawn in, and is necessary for aging.

4. Older barrels become less permeable and thus are less effective at aging.

5. An experiment at Martha's Vineyard covered barrels with oxygen-permeable polyethylene covers that tended to reduce alchohol/water loss to about 1/4th of normal evaporation, but accordingly reduced air exchange, a problem.

Whew! I'm glad this one is over...