distilled water should have no alkalinity really, or damn near none, similar to RO water.
it depends on the style you are making, whether HIGH alkalinity in your water has an impact.
I have pretty hard, alkaline water, which makes a great darker beer, but not so great for an authentic German Pils.
I have only once bought store RO water in bulk for a light beer style. I'm not sure I Have the taste thresh hold to notice the difference.
Hell I have troubles tasting acetylaldehyde 
__________________
Malkore
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10
|