RO Water - starting with lower pH

[jerrylotto]

Exactly. Too high of a mash pH is a problem for efficiency and conversion and can extract tannins, but too low of a mash pH will simply thin out the mouthfeel. Mashing all about enzymatic reactions and has nothing to do with yeast. Adjustments after the boil are another matter entirely.

That said, yeast grows and multiplies much more rapidly at a pH higher than 5.0 (5.5 is optimal), but fermentation is more efficient if the pH reading is below 5.0.