Problem hitting preboil gravity target

I'm using Beersmith and have Brewhouse Eff. set to 70% since this seemed a resonable target. The last couple batched I brewed I missed my preboil gravity target by 8 to 12 points. I'm using 1.25 lb/qt. in my mash now with a no mash out double batch sparge.

I suspected the grind from my LHBS was a bit on the coarse side. I measured the gap of their mill at .045" (they don't allow adjustments of course) They do have a nice policy where you can buy a bag of malt upfront and deduct off the balance ($48 for 50 lb. 2-row is hard to beat)

I'm not interested in buying my own mill at this point so i was wondering what people think could help out my situation. Would it help to run the grain through the mill a second time? Should I extend the time of my mash? Change my grain/water ratio for the mash?

how long and what temp did you mash at? did you check it occasionally to make sure you were not losing temp?

Also, batch sparging is usually less efficient vs fly sparging.. its possible you may not get the 70%

There shouldn't be any problem with hitting 70% while batch sparging. I regularly get 75% efficiency using the very same method.

I was getting very low efficiencies for the very same reason, coarse grinds at the LHBS. I bought my own mill and set it at 0.035 and BAM - 75%.

You may benefit from a longer mash. I would recommend drawing small samples and testing them for starch with iodine. I regularly do this and have extended a couple mashes by 10-15 minutes because they were not completely converted. When you drip iodine into the sample it will flash black if there is starch present, otherwise it will just turn ruddy as the iodine mixes in.

I would also suggest more stirring, it will help with rinsing the sugars from the grains. Anecdotally, I brewed two beers last Thursday. The first one I watched very closely, stirred it more (during the mash and the sparges) and got a efficiency of 78%. During the mash for the second beer I was busy with the first beer's boil and with cleaning carboys and other necessary tools. The second beer's efficiency was ~73%. Now, of course there are all kinds of other factors here, but I attribute a significant portion of the second brew's lower efficiency to my lack of attention.

My old LBHS had a mill with one setting and it was pretty coarse. My efficiency went up about 10% when I asked them to run the grain through twice. Since then I've been ordering more online, it's much cheaper, and using my old corona mill knock off.

every time i read here i love my home brew store more i did some wheat last week and asked the guy what mill would be better the checked the crush on them and adjusted the mill as tight as it would go and i got a great crush on my wheat.

i would try running it through twice if your crush looks bad. i always run my wheat through twice and that helps.

The gap is too big.

Unfortunately your LHBS refuses to adjust the crush for what ever reason. Milling the grain a second time could help some.

If you can't afford a mill now, consider gettting the grain somewhere else.

Mongo64 said:

I'm using Beersmith and have Brewhouse Eff. set to 70% since this seemed a resonable target. The last couple batched I brewed I missed my preboil gravity target by 8 to 12 points. I'm using 1.25 lb/qt. in my mash now with a no mash out double batch sparge.

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Hey Mongo,
Did you mean to say 1.25 qt./lb. instead of 1.25 lb./qt.? If you are actually using the ratio you say, that would be a very thick mash (0.80 qt. /lb.) and could adversely affect your efficiency depending on your procedure.

The most efficient ratio of grain to mash water is dependent on your system and mashing procedure (single infusion, step, decoction, whether you're doing a mash-out, fly or batch sparging, etc.). You may want to experiment with different ratios to see what kind of efficiencies you get.

I have been using 1.25 qt./lb. for single infusion mashes for quite some time, but I think I could be getting better efficiency, so I plan to try 1.5 qt. /lb. next time to see what that does.

Use this sheet created by Kaiser to track down what is going wrong.

Mirilis said:

Also, batch sparging is usually less efficient vs fly sparging.. its possible you may not get the 70%

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not this again.

You can practically get 70% on a no sparge.

Yeah I meant to say I'm doing 1.25qt/lb actually. My mash has been 60 min and i am hitting the target temps usually 150deg. I haven't had a problem keeping my mash temps with the Coleman Xtreme cooler as MLT.

Thanks for the tips guys. I'm gonna try running the grain through a second time. I think I'll also stir a bit more and give it 10-15 more min. I've got a refractometer on the way. Should make it easier to collect data and know what helps.

McKBrew said:

The gap is too big.

Unfortunately your LHBS refuses to adjust the crush for what ever reason. Milling the grain a second time could help some.

If you can't afford a mill now, consider gettting the grain somewhere else.

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If the 0.045" gap is too big, perhaps you can explain how I regularly get 85% efficiency with my mill that has a fixed gap at 0.045".

-a.

Bobby_M said:

not this again.

You can practically get 70% on a no sparge.

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heheh, i said it may be possible.. doesnt mean it usually happens. He could have dry spots in his mash bed for all i know and that would cause just as bad efficiency

ajf said:

If the 0.045" gap is too big, perhaps you can explain how I regularly get 85% efficiency with my mill that has a fixed gap at 0.045".

-a.

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Cuz you're just so cool.

Or, maybe his brewery set up is different, the mill is different, or he didn't use a feeler gauge to measure the gap and took the LBHS's word for what the gap was.

He's looking for help to solve an issue he's having. How does your comment help?

Oh, I just saw your sign off...

beerkrump said:

Cuz you're just so cool.

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Hardly.

beerkrump said:

Or, maybe his brewery set up is different, the mill is different, or he didn't use a feeler gauge to measure the gap and took the LBHS's word for what the gap was.

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I'm sure his brewery set up is different, but he said "I measured the gap of their mill at .045". I believe him.

beerkrump said:

He's looking for help to solve an issue he's having. How does your comment help?

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When somebody says categorically that the cause of the issue is too large a gap, and my own experience shows that this is not true, should I ignore the inconsistency or question it?
I chose to question it with "perhaps you can explain how I regularly get 85% efficiency with my mill that has a fixed gap at 0.045".
I think that this is much more likely to determine the real cause of the problem than ignoring everything that you don't believe in.


-a.

A couple of my experiences:

I average 75% when I do Brew-in-a-bag, which is no sparge. (I do a biab every 3rd batch or so.)

I tightened up my barley crusher to .030 and all I got out of it was stuck sparges. Using Kaiser's spreadsheet, I already know I average about 97% conversion with any crush I do (only did stock - .039 and lower) so I'm going to open mine up a bit - .035 probably on my next brew.

These are on my system in my house. YMMV. Your experience will probably vary.

ajf said:

When somebody says categorically that the cause of the issue is too large a gap, and my own experience shows that this is not true, should I ignore the inconsistency or question it?
I chose to question it with "perhaps you can explain how I regularly get 85% efficiency with my mill that has a fixed gap at 0.045".
I think that this is much more likely to determine the real cause of the problem than ignoring everything that you don't believe in.


-a.

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My point was that your previous comment was in no way helpful. Perhaps if you outlined your process that is successful with that grind, the OP could see his where he fell short. Without knowledge of your process, how would anyone be able to discern the reason for your greater efficiency? Plus, the OP was just letting the rest of us know what he thought might be the issue. By just stating, "It works for me.", you in no way contribute to a solution.