What acid changes
Acid neutralises bicarbonate to carbon dioxide and water. It does not generally remove calcium, sodium or other minerals. It introduces lactate or phosphate, so acid selection and dose matter. Large lactic-acid additions can affect flavour.
Check the concentration
80% and 88% lactic acid need different doses. Select the label concentration. The plan supports lactic acid at 80/88% and phosphoric acid at 75/85%. It estimates stoichiometric demand for the selected alkalinity reduction using approximate density at 20°C. Phosphoric acid uses approximately its first acid equivalent. Precipitation and eventual mash pH are not modelled.
Acidulated malt belongs in the grain bill
Acidulated malt contains lactic acid and acts in the mash. Its effect depends on the product and the rest of the grist. A fixed rule such as “1% always lowers pH by 0.1” is not a guarantee. Adjust it in the grain editor so gravity, colour and recipe values recalculate. Account for existing acidulated malt before further acid additions.
A practical approach
Water acid doses refer to cold, untreated water: mix thoroughly before heating. To correct the mash, measure a cooled sample first. Mix small corrections and measure again. Sparge water is separate: acidulated malt in the mash does not treat its alkalinity. Account for alkalinity changes in previously heated or treated water.