Doing a RIS and planning on putting in the steeping the dark grains at sparge. If I take a PH reading at like 15 minutes from the start of the mesh, the PH will be different from the end of the mash because I add dark grains at the end of he mash which bring down the PH. If I add 2 ml of lactic acid at 15 minutes it may not be enough. How do you guys do this? Do you check the PH at preboil and adjust it from there?