low efficiency

[Koryb]

I am sure this has been discussed here many times, and I am sure it has everything to do with my batch sparging, but the target OG 1.092 and what I got was 1.055. pretty crappy, I know , but maybe you can help me......

Using three Sanke kegs. Mash tun has a Bazooka tube. My grain bill was:

15.5 lbs 2-row
.5 lb Crystal 40
.5lb Crystal 60
5OZ of Black Patent

Strike water 6 gallons at 163 degrees which held the grain at 152 for an hour, and I may have lost 1 degree over the hour. Once drained I got 3 gallons of Wort. I heated my sparge water 5 gallons to 170 degrees and stired very well, let sit for another 15-20 minutes and stirred about three times. drained into boil kettle and didn't get my target Wort level, so I sparged another 2 gallons same method as listed. got to my 8.5 gallon pre boil volume. Of course you know my OG was 1.055. What am I doing wrong? PLease help.

PS.... I did not want the target OG to be 1.092 I made a mistake with the grain amount but it was already crushed and mixed so I went with it, I am ok with 1.055, but I know for the amount of grains , I should havce had a better efficiency then I did.

 

[Brulosopher]

At 70% eff, you should be at 1.072 or so, nowhere near your expectation... where'd that number come from? When batch sparging, bigger grain bills lead to poorer efficiency. Yours is probably closer to 55% or so, which isn't terrible. I recommend using BeerSmith and making sure your equipment profiles are accurate. Cheers!

 

[Koryb]

I entered all my info on Hopville's calculus with the ingredients listed above, however like said I should have had 12.5 lbs of 2row instead of 15.5 lbs. I wanted it to be more like 1.072 but once I entered my info according what I had bought for grains I knew I was in a little trouble. Do you think if my base grains were 3lbs less that would have changed my efficiency?

 

[GilSwillBasementBrews]

I entered all my info on Hopville's calculus with the ingredients listed above, however like said I should have had 12.5 lbs of 2row instead of 15.5 lbs. I wanted it to be more like 1.072 but once I entered my info according what I had bought for grains I knew I was in a little trouble. Do you think if my base grains were 3lbs less that would have changed my efficiency?

With 3lbs less of 2row you would of gotten around 1.066OG @ 75%efficiency. Not sure if the lower OG would have helped your overall efficiency or not.

Something is definitely off though according to my beer alchemy app your only at 51%efficiency to get 1.055 with that grain bill. I don't think it's the amount of grain your mashing either. Or at least I know I have used similar grain bills and gotten closer to 80-85% efficiency. Not sure what went wrong at first I would say mash too/not thick enough but being as though you mashed in at 1.5qts/# I don't think that was the problem.

Sorry I couldn't help out. If nothing else at least I'll bump your thread and hopefully someone more knowledgeable on the matter can help you out.

 

[Odin_Brews]

Sounds like you have the methods down well. Have you checked your instruments, hydrometer/thermometer, make sure they're accurate? How did the crush look?

And I can confirm that at least Ive found increasing OG = decrease in efficiency. I get 75% under 1.060, 65-70 for 1.060-1.080, and the barleywine I just made got only 55%.

Anyway Id check your instruments and brew another round, see if the problem persists or if this brew was just a fluke.

 

[CastleHollow]

When did you take the 1.055 gravity reading: pre-boil or pre-pitch? If it was pre-boil, then you're looking at a 76% mash efficiency with 8.5 gallons of wort.

 

[billl]

You are either screwing up the measurements or not draining the tun well. You got 3 gallons of first runnings and then added 5 gallons and then 2 more gallons. The grain should absorb almost no additional water after the first runnings, so you should have had 10 gallons, not 8.5.

Also, for the initial runnings, grain absorbs around 0.125 gallons/lb. For a 17lb grain bill, that would be 2.125 gallon. That means almost a gallon was "lost" if you started with 6 and only collected 3.

Before the next brew, pour 2 gallons of water in the tun and then drain it. Measure how much you lose. If it is anywhere near a gallon, you should figure out how to alter the pickup so you aren't leaving all the wort behind.

 

[Koryb]

My OG was taken at the time of pre boil and it measured at 1.055 on 8.5 gallons. I did brew another batch of stout that came out at 1.055 also. So maybe get a new hydrometer?
I do know that I lose about a gallon in the Tun from the location of the welded fitting, but I account for that when I make my calculations.

 

[Brulosopher]

My OG was taken at the time of pre boil and it measured at 1.055 on 8.5 gallons. I did brew another batch of stout that came out at 1.055 also. So maybe get a new hydrometer?
I do know that I lose about a gallon in the Tun from the location of the welded fitting, but I account for that when I make my calculations.

You want post-boil OG, which mad likely closer to what we've all been predicting, putting you close to 70%... which is great!

 

[Koryb]

Forgive the question as I am still somewhat new ( only my 3rd all grain brew) why does the OG change from pre-boil to post boil? I understand some boil off but I only lose about a gallon during boil off.
I normally check my OG at post boil, but since I went to all grain I have been checking at pre-boil so I would how we'll my efficiency was and if I was getting all my sugars before I started to boil. I did go buy a new hydrometer because I didn't notice it until I wrote it down that both batches I brewed that had the exact same OG reading. A little to weird for my liking especially because the grain bill was similar but about two pounds lighter overall.
Now if I brew up another batch I will be doing a porter, one more of extract brews that I want to convert, any tips on my sparge that I should know to help?
Thanks all, I appreciate it...

 

[Brulosopher]

Forgive the question as I am still somewhat new ( only my 3rd all grain brew) why does the OG change from pre-boil to post boil? I understand some boil off but I only lose about a gallon during boil off.
I normally check my OG at post boil, but since I went to all grain I have been checking at pre-boil so I would how we'll my efficiency was and if I was getting all my sugars before I started to boil. I did go buy a new hydrometer because I didn't notice it until I wrote it down that both batches I brewed that had the exact same OG reading. A little to weird for my liking especially because the grain bill was similar but about two pounds lighter overall.
Now if I brew up another batch I will be doing a porter, one more of extract brews that I want to convert, any tips on my sparge that I should know to help?
Thanks all, I appreciate it...

That gallon of boil off has an impact on OG. Every recipe out there uses post-boil OG; pre boil is mainly to help determine mash efficiency.

 

[Yooper]

Forgive the question as I am still somewhat new ( only my 3rd all grain brew) why does the OG change from pre-boil to post boil? I understand some boil off but I only lose about a gallon during boil off.

The SG changes because the density of the wort changes. If a gallon of water (boil off) is removed, then the SG will be higher. The sugar content remains the same, so it's the same amount of sugars in less liquid. I hope that makes sense!

One reason for a wrong pre-boil gravity reading is not cooling the sample before testing. I know they have 'correction tables' but any sample over about 100 degrees will be notoriously inaccurate. So cool the sample in an ice bath or in your freezer, and then take the reading when it's under 90 degrees and then use the correction table.

As far as tips on the sparge, it depends on whether you're batch sparging or fly sparging.

 

[RmikeVT]

Forgive the question as I am still somewhat new ( only my 3rd all grain brew) why does the OG change from pre-boil to post boil? I understand some boil off but I only lose about a gallon during boil off.
I normally check my OG at post boil, but since I went to all grain I have been checking at pre-boil so I would how we'll my efficiency was and if I was getting all my sugars before I started to boil. I did go buy a new hydrometer because I didn't notice it until I wrote it down that both batches I brewed that had the exact same OG reading. A little to weird for my liking especially because the grain bill was similar but about two pounds lighter overall.
Now if I brew up another batch I will be doing a porter, one more of extract brews that I want to convert, any tips on my sparge that I should know to help?
Thanks all, I appreciate it...

The OG changes because you lose about approx 1 gallon of water over a 60 minutes boil. This is pretty significant when boiling close to 7 gallons of liquid. You need to take OG post boil before pitching. It changes significantly.

If you have lets say 8.5 gallons of wort pre-boil and have a gravity of 1.055 then you have (8.5g * 55 Gravity Points) = 468 Gravity Points; Then you reduce the liquid level to lets say 7.5 gallons you have an OG of 1.062
down to 6 gallons and you have 1.078 which is were you probably should have landed. I think you sparged too much water or didn't calc correctly.