Through a bit of poor planning, I appear to be a bit short on CRS for a brew at the weekend. I have enough CRS for setting up the mash so I know I'll hit my pH fine, but I'll need to make sure my sparge water is OK and doesn't push the pH up too much - I have some lactic acid which I could add in small quantities, but does anyone know the reduction in alkalinity that a given concentration of lactic acid will have per litre? (much along the lines of CRS being, from memory, 180ppm as CaCO3/ml/litre treated)
If not, I'll have to do the titration with methyl orange, but in case anyone has already done it or knows the figures...

Thanks!