Lewis Perin wrote:
I've often thought
it should be cheap and environmentally responsible to try to emulate
good mineral waters by adding the right salts to tap water.

Yeah - be a heck of a lot more convenient than schlepping water home
from the market. I've tried a few saltoid addenda, including sea salt,
garden lime, crushed dolomite and alum, but none worked very well. When
the need seems to arise, I just add a small splash of bottled mineral
water - full strength is far too much.

A critical option is brew vs. spike: add minerals to the brewing water,
or to the brewed infusion off the leaf. They both work, and I usually
can't tell the difference. (Of course, I can't tell tea from coffee
without a look at the label, but that's another story.) This casts some
doubt on the extraction-variables case - though whether or not ions
matter much in brewing (as distinct from effects on the tongue, or in
binding solutes in various ways), I remain convinced that extraction is
indeed affected strongly by small changes in pH.

-DM