I just brewed a milk stout and have had success with hitting my target ph with BIAB. Unfortunately, I am doing batch sparge equal runnings right now as a way of learning a new skill and the ph is way low compared to the estimate in Brewersfriend. It started 5.0 low and then slow rose to 5.15 instead of the 5.47 I was targeting. I double-checked my work, my grist info and also the water source report (crystal geyser). It seems like I would have had to put in triple the amount of lactic acid (which I didn't) to make such a big difference. And, I did recalibrate my Milwaukee meter. Here's the grain bill.. Amount Fermentable PPG °L Bill % 5.5 lb United Kingdom - Maris Otter Pale 38 3.75 79.1% 2.4 oz American - Caramel / Crystal 40L 34 40 2.2% 7.2 oz American - Caramel / Crystal 60L 34 60 6.5% 1.2 oz American - Caramel / Crystal 90L 33 90 1.1% 3 oz United Kingdom - Black Patent 27 525 2.7% 3.5 oz Lactose (Milk Sugar) - (late addition) 41 1 3.1% 6 oz German - Carafa II 32 425 5.4% I added the water adjustments.. 2 g Calcium Chloride Water Agt Mash 1 hr. 0.5 g Epsom Salt Water Agt Mash 1 hr. 2 g Gypsum Water Agt Mash 1 hr. 2 g Baking Soda Water Agt Mash 1 hr. 0.5 g Slaked Lime Water Agt Mash 1 hr. 2 ml Lactic acid Water Agt Mash 1 hr. Any suggestions on what I can look at discover where I went wrong in the calculations or my process?