how much sparge water is to much?

[George]

...
I'll also take issue with batch sparging being more efficient than fly sparging...

I won't argue with you there. A well-designed fly system will almost certainly have a greater potential for efficiency than a batch system. I was recommending that insco32 try a couple batch sparges to see if his low efficiency was caused by the mash (pH, crush, or schedule) or if it was caused by the sparge (tun geometry, manifold, or speed of runoff). A batch sparge takes the sparge out of consideration, so to speak. If batch efficiency goes up compared to fly, it means the mash is pretty good and you should take a look at your MLT design and fly sparge procedures. If the batch efficiency stays low, but relatively the same as the fly, take a look at mash parameters.

I was just recommending a batch trial as a diagnostic technique, not that he switch. I'd probably switch to fly sparging myself except that I'd need another pump. Like you, I don't really save any time.

[mmayer]

My process has always been to sparge to a fixed boil volume based upon a consistant evaporation rate and boil time. Only a handfull of times in many many batches have I checked the gravity at the end of the sparge, and I have never come close to the 1.010 shutoff point, so I just never worry about it. Since I usually hit my OG numbers within a couple of points, this procedure seems to work well. I do 10 gallon batches, fly sparge, and have a fairly consistant efficiency of 75%.

[Chris Vejnovich]

Danno makes some very good points on crush and eff. But I will say that my non-adjustable JSP gets me 72-75% with NO problems noted. I probally could crush a little finer, but I am fine with the eff that I am getting. I also agree that if you have about 75.00 bucks to spare, get yourself a hydrometer. I have promash as well and when I have taken readings of wort at sparging temps (160-168F) even Promash did not correct them completely right because when I let the sample cool to 60-70F I got a much higer reading than the corrected temp that Promash gave. I also wonder sometimes if these guys who are reporting 85% eff are over sparging because they are just sparging to a set volume and not a set terminal gravity of the wort coming out of the mash. I often stop sparging at 1.014 if I am really close to my needed volume in the kettle. I would rather make sure that I don't oversparge than undersparge a bit. A side note on the eff thing is that many brewpubs get about 80-85%, and they often sparge down to the last possible drop to get the most out of their grains because they are hoping to save a few thousand lbs of grain over the course of a year.