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Old 10-02-2011, 07:50 PM   #1
Toivo
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Default Preboil volume question

I recently switched to a half barrel for a boil kettle and have been struggling to hit my post volume target. If I collect 6 1/2 galons pre I am boiling off more than I use to. I get I need to collect more pre boil so do I just sparge with more water? What other adjustments should I make. Also when I mash I end up with close to 50% absorbed by the grain is this normal? I am trying to get more consistant with my brewing and this has been a struggle.

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Old 10-02-2011, 09:49 PM   #2
waldoar15
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I can't answer all of your questions, but a larger surface area is going to give you a higher boil off rate.

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Old 10-03-2011, 01:46 PM   #3
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Also, take a look at your MLT before adding grains.

Set it up near a sink or outside and leave the valve open. Add water to it until it starts to come out the spout. Stop adding water and let the water finish flowing.

Close the spout, measure the amount left in it. This is the dead space in the MLT that doesn't drain. Because of the way I have mine setup, I lose about a quart. Yours may be different, but you should factor this into your volume calculations.

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Old 10-03-2011, 02:13 PM   #4
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Quote:
Originally Posted by hiphopopotamus View Post
Also, take a look at your MLT before adding grains.

Set it up near a sink or outside and leave the valve open. Add water to it until it starts to come out the spout. Stop adding water and let the water finish flowing.

Close the spout, measure the amount left in it. This is the dead space in the MLT that doesn't drain. Because of the way I have mine setup, I lose about a quart. Yours may be different, but you should factor this into your volume calculations.
?????? What does this have to do with boil-off??????
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Old 10-03-2011, 07:12 PM   #5
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Quote:
Originally Posted by Toivo View Post
Also when I mash I end up with close to 50% absorbed by the grain is this normal? I am trying to get more consistant with my brewing and this has been a struggle.
Just saying it's not all grain absorption.
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Old 10-03-2011, 10:16 PM   #6
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Quote:
Originally Posted by hiphopopotamus View Post
Also, take a look at your MLT before adding grains.

Set it up near a sink or outside and leave the valve open. Add water to it until it starts to come out the spout. Stop adding water and let the water finish flowing.

Close the spout, measure the amount left in it. This is the dead space in the MLT that doesn't drain. Because of the way I have mine setup, I lose about a quart. Yours may be different, but you should factor this into your volume calculations.
Good idea. Never thought of that til yesterday when I brewed. After it quit running I used a spoon to push my Braided hose down and got more runnings out. I plan on making a manifold now that will stay on the bottom instead of lifting up. Also plan on not boiling quite as hard next time.
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Old 10-03-2011, 10:36 PM   #7
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Here is whatI did and I get very consistent results.

1. Measure out about 7 gallons and boil it for an hour in your kettle. Measure how much water is left. This will give you your rough boil off %. Yeah temp and strength of boil will effect it but it will get you close enough.

2. Figure out what your total pre-boil volume needs to be to boil down to your final volume needed. For my system 7 gal of wort boils down to 5.5 gal in the fermenter almost always.

3. When sparging collect your 7 gallons and then measure your gravity. If its too high keep sparging untl you hit it and then just dump out the excess to make sure your putting the 7 gal (in my case) back in for boiling.

If its too low add DME or malt extract. (There are alot of calculators out there to figure out what you PreBoil Gravity should be and what your final gravity will be based off your boil off %. I use Beer Smith.

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