Final Runnings Gravity

Can anyone give me a brief rundown on some sparging stats? I just upgraded to an all grain system and am working out the kinks, but I’m not getting efficiency above 70%.

  1. At what point does pH become problematic? I know that a pH of 5.2 is what you’re looking for in the mash. I see in BeerSmith there is a field for pH of final runnings. Is there a point when you should stop sparging?

  2. What should be the gravity of the final runnings? I fly sparge and take a full 30 - 40 minutes to complete the sparge. When I measured my final runnings today it was ~ 1.040 (corrected for temp. w/ hydrometer). That seems awfully high. Is it?

Any advice would be appreciated. Thanks!

Look at your crush first.

I batch sparce but my final runnings are more in the 1.025 range

To be safe your gravity should be no lower than 1.012. If yours is 1.040 your leaving a lot of sugar behind which would account for your low efficiency. Extend your sparge time to 60 minutes and monitor your gravity. You may want to consider changing to batch sparging. It’s a lot shorter and easier.

I stop sparging when I get my kettle volume. Of course I batch sparge so at that point my mash tun is pretty much empty.

I measure PH of my mash at the beginning (occasionally) but don’t worry too much about it after that.