Re: mineral content in water
Same basically holds true for brewing beer, and I would guess wine as well – although oenologists spend far less time talking about water than zymurgysts do. In wine, it is probably more or less the same thing as terroir… the distinctive taste a specific range of land leaves on the grapes. However, with grapes the water and mineral content are taken in vascularly instead of as a chemical additive when brewing a wort.
Dozens, perhaps scores of times, I have had a discussion with another brewer about my Newcastle-style brown ales. It is a notoriously finicky recipe to get right, and it is the mineral content of the water which matters. (No recipe on hand now, but I think it is natron – or soda ash – which is in fairly high concentrations in Newcastle… and without it you’ll never achieve the same chewy texture.) There are other examples, but none other so dramatic so far as I know.
The bit about DI water causing a greater corrosive effect is interesting. Never really gave that much thought.