Surprised by efficiency

I made this recipe last saturday, and I was very surprised at my 62% efficiency.

http://hopville.com/recipe/1654143

I reached my boil volume and then I stopped sparging and the runnings were 1.020. I was wondering if there are any tricks to pull more from my fly sparge without increasing the volume and boil longer? I have created other recipes that have less grain bill and made more than 75% efficiency.

My setup is a 15 gallon pot and NB 5Gal Deluxe All-Grain Setup for fly sparging.

Any advise would be great.

That's not a huge grain bill and fairly simple too. Sometimes larger grain bills will decrease efficiency. Couple of questions ... Do you crush your own grain or get it from a place that you trust would crush consistently? How long was your mash? If something was slowing your conversion (crush, temp, pH, etc), then maybe you still had conversion happening as you sparged? I know that before I got a grain mill, my LHBS crush was pretty poor. I listened to some podcasts where Kai Troester explained how to measure mash and sparge efficiencies separately to help diagnose problems (excellent listen BTW). I found that with my typically poorly crushed grain I had mashes that would go for nearly 2 hours and still be converting. In other words sparging was not my problem at all, and thus the reason I bought a mill. I would think that if you had a slow conversion and you sparged while conversion was still happening you could end up with full boil volume and final runnings still at 1.020.

I crush my own grain, and have crushed numerous batches. The only thing I changed was I sparged for a longer amount of time. I didn't think that would change anything.

Any ideas or was it just a fluke?

brans041 said:

I crush my own grain, and have crushed numerous batches. The only thing I changed was I sparged for a longer amount of time. I didn't think that would change anything.

Any ideas or was it just a fluke?

Click to expand...

Did you do anything that would have measured the progress of the mash? E.g. gravity measurement before sparging, or iodine test?

brans041 said:

I crush my own grain, and have crushed numerous batches. The only thing I changed was I sparged for a longer amount of time. I didn't think that would change anything.

Any ideas or was it just a fluke?

Click to expand...

I don't fly sparge so take this with a grain of salt ...

I guess longer sparge implies slower flow rate. Seems like that could reduce sparge efficiency. I realize there are tradeoffs to avoid channeling. For fly sparging I thought a rough rule of thumb was 1 qt/min. How fast were you relative to that?

I'm still not totally convinced your problem is a sparging problem. Until you measure more you can't really know whether it was conversion or sparging.

If you sparged longer, and at the same rate, and did not boil longer, that would get you a lower S.G. Did you measure runoff volume? S.G. before and after boil? Adjusted S.G. for temperature and was the temperature within 30 degrees of the calibrated temperature? Did you use different water? Did you do an iodine test before sparging?

There are many, many reasons for efficiency variation. The only way to diagnose is to measure at every step.