Hi Archus,
Supposedly The PH of distilled water when first distilled is 7.0. If it sits in an open container it will react with the Carbon dioxide in the air, and the PH will drop to about 5.6.
But since distilled water pulls the inorganic minerals from the body, one would think that that process would lower the body PH.
I distill my own with a "Water Wise" distiller with a carbon after filter. I put it into capped glass bottles. If you don't drink all that you pour, the PH will drop some I suppose. I would worry more about what is not in my water rather than PH.
If you could see what burns off in the bottom of my distiller, you would never drink tap water again.
Water Wise sent me an offer to buy another one the other day, and in it was a comparison chart.
Chart had 18 contaminants found in water.
The only one Bottled water removed effectively was Chlorine
Carbon Filter removed Bromoform, Chorine, MTBE. Significant reduction, lead, Mercury, Arsenic. No reduction for 12 remaining.
Reverse Osmosis Significant reduction Arsenic, Bacteria, Nitrates, failed to remove, Viruses 14 left= okay
Waterwise distiller with carbon filter Removed all contaminates.