Angel’s Share or Devil’s Share?
A couple of days ago, the Sherry Advent Calendar featured a photo of the distinctive black stains that adorn every bodega’s walls. These stains are caused by moulds which feed on the ‘Angel’s Share’ of the sherry that evaporates.
One of our Facebook followers got in touch to ask the following:
Can you explain why in whisky the angel’s share is the alcohol and so the alcohol level drops during maturation, but sherry apparently becomes more alcoholic the longer it matures? Alcohol being more volatile than water, the whisky description makes more sense.
This is a great question, and I thought others might be interested in the answer too. If you’re into whisky you’ll be very familiar with the term the angel’s share – and you might even have seen the movie of the same name (which, by coincidence, our friend Marion had a part in!) – but the effect is somewhat different in sherrymaking.
A little alcohol is lost for the same reasons as it is lost from whisky (and this contains nutrients for the mould in the photograph). But this is far outweighed by the loss of water, which is due partly to the high temperature in the Sherry Triangle, but predominantly the very low humidity. Consequently there is an osmotic effect, drawing the water through the barrel into the air. This leads to a concentration of alcohol (and flavour compounds) in oxidatively aged sherries over time.
This process – the merma – leads to 4% of the sherry volume being lost every year. It’s not surprising then, that in his book Sherry Uncovered, Beltran Domecq (the current president of the Consejo Regulador) questions whether it ought to actually be called the devil’s share!NB Biologically aged sherries (fino and manzanilla) experience a small reduction in alcohol year on year, as the flor consumes alcohol as well as sugars.