However that minimum pricing does seem to disproportionally effect the young.
It all depends what the "young" are drinking and if it's cheap, high-strength alcohol, e.g. white cider (actually a by-product of sugar beet refining), white-label vodk,a "super lager" or any form of fortified wine.
I would say that the minimum pricing will disproportionately affect anyone who likes to drink to excess on the minimum budget. If you're a well off soak who specialises in red wine and gin, this won't hurt your pocket, if you're scraping together the fiver for a bottle of White Strike cider then this significantly increases what you need to pay to get soused.
Of course, inn theory nobody under the age of 18 should be affected (of course we know this is wishful thinking).
I do imagine that the bootleg black market spirits market is going to boom, which is dangerous considering what can end up in that stuff. But then again it's dangerous enough drinking the genuine stuff on the cheap...
is going to have to get back on the white spirit
I thought white spirit just refers to mineral-based solvents e.g turpentine substitute which come from naptha or petrol. Don't you mean methylated spirits? Which you can buy very easily in large quantities now off the shelf because of the fashion for "real flame" burners and scented wicking vapour things that burn alcohol. And fondue is making a comeback too.