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Old 07-17-2012, 10:23 AM   #1
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I have no idea why this is occuring but I am consistently achieving a gallon to a gallon and a half more wort for the pre-boil. My pre-boil gravity for the last brew was way off 1.036 instead of 1.056 for a mash efficiency 62.7%. I was supposed to have 7.69 gallons according to BeerSmith and ended up with 8.5 I have re-calibrated the sight glass it was off slightly before this brew.

In the past I have ended up with as much as a 1 3/4 gallons extra but my efficiency was much higher (82.7%).

I generally don't mind having more wort (I typically boil off 2 gallons per hour) and come close to the post boil gravity, however, with the lack of efficiency this time and the increase amount of wort, I am becoming concerned there is a larger problem occuring in my brewing process.

Any ideas why this is happening and what I can do to address this problem? Should I be concerned?

Thanks!

 
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Old 07-17-2012, 10:26 AM   #2
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...also for the last brew I did one large sparge of 6.24 gallons instead of two smaller ones. I think I read somewhere it will produce a smoother beer (this is a sweet stout). This is the first time I have done this.

Thanks again.

 
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Old 07-17-2012, 10:58 AM   #3
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How many times has this happened, twice? Not sure exactly, but my guess is a number of things:

Your settings in BeerSmith may need to be adjusted to account for your set-up
You're sparging with too much water
You're running off more volume than you need

I'll occasionally have liquid left in my mashtun after I'm done lautering. We draw that off to make a small beer in a separate brew kettle.

 
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Old 07-17-2012, 01:02 PM   #4
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I always have some water left in my mash tun. I just shut off the sparge and spigot from mash to boil when I get the volume I want. Every system is a little different - you need to account for the way your system works.

 
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Old 07-17-2012, 01:45 PM   #5
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In addition to whatever beersmith might be telling you, I would also advise measuring the amount of runnings produced, and in the kettle prior to your last sparge, the wort needed to reach your preboil volume will be your last sparge amount...KISS principle and also a confirmation of what the software should be telling you...brewing software can be a great tool, but keeping your eyes open and having a hands on grasp of the basic concepts goes a long ways IMHO.

Sorry, but no idea why your gravities are amiss.

 
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Old 07-17-2012, 02:17 PM   #6
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Thanks for the responses. This (extra wort) has happened for several brews (four or five probably more). I believe the efficiency is probably off due to the one sparge method and am thinking of changing the "Tun Deadspace" in BeerSmith as it is set to .80. I put a gallon of water in my mash tun and had 12 oz of water at best of water left. Not a math whiz, I don't believe that is necessarily 80 percent of a gallon...I need to do some math...

 
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Old 07-17-2012, 02:38 PM   #7

On my first ag i set the tun dead space to 0 and set pre boil to 6.5. I mashed 16.5 qt for 12.5lb of grain and got back 2.5 g but i also tipped my tun to about 45 degree to make sure i got that. than sparged with 4.2 gal and got back the 4 i needed to to hit my pre boil. while i was boiling i let my tun trickle drain and had a little less then a qt sitting there when i was finished boiling. my post boil was 5.4g being my first i figured i "reverse engineer" the process to see how my system worked.
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Old 07-17-2012, 08:47 PM   #8
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Mash tun dead space would be a very good place to start. The thing with the dead space is once it's full of liquid, it's full. If you measure how much water you mashed-in with, and how much you've colleced with your first runnings, the difference is your dead space. After the initial run-off, the dead-space is full of liquid so any additional batch sparges should yield the same amount of liquid in and out regardless of your dead space.

 
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Old 07-17-2012, 09:44 PM   #9
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Quote:
Originally Posted by annoyingrob View Post
If you measure how much water you mashed-in with, and how much you've colleced with your first runnings, the difference is your dead space.

Sorry to be annoying rob....hahah

...but the difference would be your dead space plus grain absorbtion.

 
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Old 07-17-2012, 09:52 PM   #10
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Are you batch sparging? (It sounds like you are).

If so, there is a very easy fix. Mash as usual, and then measure the first runnings. Then you'll know exactly your grainbed absorption and your dead space. Subtract the amount of your first runnings from the desired boil volume, and then sparge with that amount (and one round of the full amount is fine).

Then, tweak all of your Beersmith settings to your actual results. We can help you with that.

After that, you should be dead-on with Beersmith.
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