I'm wondering how I would manage the water volumes for a lower gravity brew?
Right now, I'm putting 22-23L of water into my tun which equates to about 2L/lb because I'm usually at about 10 lbs total grist. From this I normally get about 14L of wort at around 1.070-1.072. I then add 16 to 18L of hot water, batch sparge and get about 16L of second runnings for a total of 30L which works out very well for my 23L fermenters. I don't take the gravity of the second runnings but I do take the gravity of the final pre-boil volume which has been about 1.044 or so the last couple times.
But, I want to reduce the gravity of my beer down to 1.040 OG, post boil. I will reduce my grain bill accordingly but what do I do with the water volumes? If I stay at 2L/lb, I'll only put in about 12L at the start and I expect I'll only get about 8L back from that. Do I then put 22 more in the tun for the sparge or should I stick with the 22/16 ratio? I know less grain will hold less water so I may not get as much absorption so 20/14 may give me what I need but I'll still have over 3L/lb in the mash tun. Is this a problem? I see most people are somewhere around 1-1.5L/lb, I started there but got better efficiency at 2L/lb.