Originally Posted by DWFII
I may be wrong or only partly right but as I understand it most of the flavour imparted by the wood is esters extracted from the wood and from the charring that is given the wood.
Most, sure. Minerals have a very faint taste in general. Have you ever known a (natural) mineral water to taste particularly strong, much less anything like an aged liquor? Distilled water tastes bad because we unconsciously notice the lack of minerals, but most decent "clean" waters are going to taste very very similar unless they're deliberately stocked with extra minerals (or contaminated with sulfur, etc).
Most of the difference in flavor from cask strength to the final, diluted, form comes from altering the concentrations of those various organic compounds (esters, etc), not from the minerals in the water. I'd guess Islay scotch may be the rare exception, with their "living water" and all.
That's a point worth considering but whisky itself is distilled. Whatever minerals are in the water are left in the mash tun. Adding water, even from the original source, is altering the native flavour of the whisky. And adding mineral (flavoured) water from a disparate source is murder.
Maybe it's a good reason to drink malt neat...if you need one.
Whisky is not traditionally drank at cask strength, so I don't think that flies. In the old days, you'd be drinking locally produced whisky and could dilute it to your taste with mostly the same waters used by the distiller. As it moved farther and farther afield, that became less of an option. Using filtered or spring water is as close to the original method as you're realistically going to get. That's more faithful than using distilled water, and would taste better to boot.
It's not a religious ritual to most people. You do the best you can, get the highest quality end product you can reasonably attain. Drinking cask strength out of a quest for purity is odd to me, especially since most distillers are going to dilute their product to their taste at the source. Few would take offense if a consumer's taste led them to slightly dilute the product more, using whatever water they so chose.