[Pricelessbrewing]

I agree with you on the consistency thing.   I'm just still surprised by how my efficiency has dropped from 80% for  fly sparging to mid-60's for no sparge.   If this is what it's going to be, then fine, I'll adjust my recipes.   I'm just wondering why such a drop.    Is it a solubility thing?  Don't know.

It's not about solubility, it's about dilution. Solubility limit of sugar solutions are around 1.300, so it's definitely not that.

When you mash, the starches are converted into sugars and that sugar dissolves into the wort. The resultant wort volume is higher than the original strike water volume by approximately

WortVolume=Strike + (0.0016 * GrainPotential*GrainWeight)

Then the run off volume is Strike Volume - absorption rate, leaving behind a known volume in the grain, and grain bed. When you sparge (batch), you're diluting this reminding wort volume with the new sparged wort volume (retained wort volume + sparge volume). It's all 100% dilution based.

Fly sparging is unique since it relies more on even water dispersion and should exceed the lauter efficiency of a batch sparge process when done properly, in equipment suited to fly sparging

Again, if you check out my calculator above you can see how a batch sparge and no sparge should go. Something I'm learning recently is that, for whatever reason, recirculation seems to improve lauter efficiency in some way similar to fly sparging. Haven't quite figured out how yet.

[erockrph]

I get about 80-84% efficiency (based on my preboil volume/gravity). But I use a grain bag in my mash tun (BIAB-style), so I effectively have zero dead space.

What mash thickness are you guys using? Are you using your full volume of liquor in the mash, or are you topping off in the kettle? Thinner mashes will leave less extract in the mash tun. I shoot for ~ 3 qt/lb on most beers.

[natebrews]

I put in the full volume, 8.5gallons or so.

[VictorBrew]

Anything 1.055 and under I go full volume.  Up to 1.070 I employ a thicker mash and  I have to top up in the kettle purely based on mash tun size limit.  I very seldom brew anything bigger then 1.070, but if needed I will swap in a bigger mash tun and go full volume.

[802Chris]

I don't have a single infusion data point since I have no done one in many years. I step mash, keep my WTG ratios under 3qt/lb,  have no deadspace in the mash tun and .08 grain absorption. 100% conversion/90% mash/85% brewhouse.

FWIW these are almost exactly what I hit consistently. I mash in a cooler with a Brew Bag. I only drop to about 87% mash eff when I no sparge, but I do this by extending to at least a 90 minute mash or stirring a few times when I'm in a hurry. I shoot for a WTG of around 2 when batch sparging.

EDIT: Oh yea, and I crush the living P** out of my grain with a corona mill. Only possible now with the Brew Bag