Help with increasing mash efficiency

[kevindalyus]

Thanks in advance for any help with this issue. In a nutshell, two all grains brewed, two terrible efficiency results (50%-60%). For reference, recipes were created by my brew store in chicago, so I know the weights of grains were correct. I built my mash tun with brand new rectangular Igloo cooler, stainless steel braided flex line (18") and ball valve for flow control. My HLT is a 5 gallon Igloo cooler with ball valve for flow control as well.
On brew day, heated strike water to 175, added to cooler, poured in grains (came out to 3 gallons of water for 12lbs of grain) and stirred. Mash temp settled in at 154 degrees and I closed the lid for one hour (at this point, I can't see anything that I could do differently).
After one hour, I collected about one gallon of wort and poured back on top of grains, opened up my HLT (filled with 5 gallons of 180 degree water) and laid the hose on top of the grain bed making sure the water was circulating on top. I then opened my valve on my mash tun and started the running into my kettle. This whole process took about 45 minutes (I was shooting for one hour).
And that's about it. I collected 6.5 gallons of wort and started my boil.
Before pitching, I checked my OG and it came in at 1.042 (target of 1.059), and yes, that OG is adjusted to temperature of 70 degrees. My previous attempt was 1.045 (target of 1.068)
I've searched this forum, watched way too many youtube videos of guys brewing, but still I can't seem to figure out what went wrong.
Any help would be greatly appreciated.

[Bugeater]

Your basic process is sound. The only thing I would change on that part of the problem would be to thin out your mash a bit. You were mashing at 1.0 quarts of water per pound. Increasing that to 1.5 qt/lb (you can go as high as 2.0 qt/lb) will help a bit with efficiency.

This, while helpful, will not bring the efficiency to where you need it. Most efficiency problems are due to under crushing the grain. Some LHBS will do this intentionally to help brewers avoid a stuck sparge. More often, the gap setting on their mill will change slightly over time. Also different malts will vary in the size of the kernels and even the same malt will show variance in kernel size from lot to lot.

You should ask your LHBS to adjust the mill to a closer gap the next time you get grain. If he won't do that, ask him to run it through the mill twice. The finer the crush, the higher the efficiency. The problem with getting it too fine is that you may get a stuck sparge. In addition, you need to check the crush after the first half pound or so. You want to pay attention to the husks. They should be cracked and flattened but not pulverized. If the husks are too pulverized, you may get unwanted tannin extraction.

Different mills will crush a bit differently. My mill (a single roller Phil Mill) can crush my malt almost to a coarse flour and yet leave my husks pretty much intact. I get about 80% efficiency batch sparging using this. I have seen other mills that will pulverize the husks while not crushing the kernels nearly as much as mine. Don't have the mill adjusted too much at a time. Mill a little and check the husks.

Hope this helps a little.

Wayne

[siwelwerd]

For reference, recipes were created by my brew store in chicago, so I know the weights of grains were correct.

Not sure how that follows. They could certainly make a mistake. That this happened twice does make that unlikely.

I'm with Bug, the crush is probably the issue, that's where I'd start. You could also have some channeling during the sparge depending on the exact design of your manifold.

One stupid thing you can do: Make sure your thermometers and hydrometer are calibrated. Unlikely, but easy to check.

[kevindalyus]

Thanks for the advice. I use the store's mill (double roller) and have used their suggested setting, so I never really check the actual grains after they've been crushed. So to be on the safe side, I may try to crush them a bit more.
I was just wondering if there is still any clear preference to batch vs fly sparging. But it seems that if I do the process correctly, it really shouldn't matter that much.
I'll try to thin out the mash and crush the grains more. Can those two things really boost the efficiency to where I need it to be?

[snowcapt]

Thanks for the advice. I use the store's mill (double roller) and have used their suggested setting, so I never really check the actual grains after they've been crushed. So to be on the safe side, I may try to crush them a bit more.
I was just wondering if there is still any clear preference to batch vs fly sparging. But it seems that if I do the process correctly, it really shouldn't matter that much.
I'll try to thin out the mash and crush the grains more. Can those two things really boost the efficiency to where I need it to be?

Those two things done correctly will have a huge impact on your efficiency. With the crush, you will be making the starch more available for conversion. With a higher grain/water ratio, the mash water will have more "room" to accept more sugar into solution. It will be less dense and things will work out much, much better. 2 seemingly minor things, will provide, if correctly executed, a much better extraction rate.
Good luck, and let us know what you change and lets see how your efficiency jumps up to something a little more promising.

[dmtaylor]

Yes. It was undoubtedly the crush. LHBS's are notoriously bad at crushing grains, which is why many folks resort to a double crush to ensure it comes out fine enough. Otherwise, who knows what efficiency you'll get!

Mash thickness, to me, is of less importance than the crush, but it might make a little difference. Don't fear a thinner mash -- there are no real disadvantages, only advantages.

Batch sparging vs. fly sparging is moot. You can kick butt with either one.

[kevindalyus]

Excellent. One last question: am I supposed to check the OG before the boil, ie take a sample of wort, try to cool it down quickly, and then check the OG? I read a couple articles saying that should be a step before boiling, with an OG target of 1.008

[snowcapt]

Excellent. One last question: am I supposed to check the OG before the boil, ie take a sample of wort, try to cool it down quickly, and then check the OG? I read a couple articles saying that should be a step before boiling, with an OG target of 1.008

I dont check it until it comes out after the boil. I think checking it before is more of a way to track proper extraction, I think a refractometer would be helpful for this. I just check it after it is done, so I know what I am dealing with.