Mash ph Addition

The amount of a specific acid is computed with the Mash ph Adjustment.

For a BIAB operation should that acid addition amount be done prior to the start of steeping or after the bag has been pulled?

The purpose of mash pH adjustment is to target the pH of the mash to a value which enables good enzyme activity.  In order to do this, you will want to make any additions to the strike water before you dough in with your grains.  It typically takes at least 10 minutes for the acidity of the grains to affect the mash pH and generally 15 minutes before the pH becomes stable.  Since the majority of starch conversion to sugars is done in the first 20 minutes (give or take depending upon crush), adjustments post addition of grain are less effective.

What a great answer -- the answer and good rationale. 

Thank you.