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Old 04-15-2009, 01:21 PM   #1
Brutus Brewer
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Last week I brewed my first original recipe, a pale ale. Prior to the brew day I constructed a measuring stick by pouring 1 gallon of water in my brew pot and noting the level on the piece of cpvc pipe I was using. I did this for 10 gallons of water. With the help of Promash I calculated needing 6.875 gallons of wort to the boil to reach my target volume of 5.5 gallons after evaporation. Knowing this I collected just over 7 gallons from the mash and began my 65 minute boil. When it was all said and done I had 4 gallons to transfer to the fermenter, so over the course of the 65 minute boil I lost over 3 gallons to evaporation. In case you're wondering that's almost 6 ounces per minute. I even lowered my boiling temperature to slow down the evaporation rate. Now, I know there is a shrinkage factor as the water cools, but wow, this is getting very discouraging. This was my 4th all grain brew and they have all been like this with one exception where I intentionally collected like 8.5 gallons and my boil off wasn't near what it was last week. I have been doing this inside my garage but I can't believe that this is the root cause. Any ideas?

 
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Old 04-15-2009, 01:34 PM   #2
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I have to be skeptical of a 3 gallon per hour boil off rate. Are you 100% positive you measured the volume accurately?
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Old 04-15-2009, 01:42 PM   #3
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That does seem excessive. Make sure you account for the expansion of hot water (you said you did that). I multiply the measured volume by .97 if the temp is @ lauter temp (~170-ish) and multiply by .96 if it's near boiling.

Also, make sure the volume measurements are accurate. I measure my pre-boil volume in the kettle but then measure my final volume in the carboy...the measurements in those two vessels needs to be accurate.

And lastly, let the wort cool before you take your hydro readings...don't do it while it's warm and add the 'correction factor'...it's just adds to the potential error.
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Old 04-15-2009, 01:59 PM   #4
The Pol
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What is the diameter of your kettle?

What are you using to boil? Electric? Gas? How many BTU burner?

 
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Old 04-15-2009, 02:47 PM   #5
camiller
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Ambient temperature and humidity? The cooler/drier the air around your kettle the more readily it will take moisture away from your boil. Also if the wind is blowing your evaporation rate will go up, although you said your in a garage. When I started using a fan to knock down the foam to reduce boil overs my evaporation went up.

 
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Old 04-15-2009, 04:57 PM   #6
Brutus Brewer
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Quote:
Originally Posted by The Pol View Post
What is the diameter of your kettle?

What are you using to boil? Electric? Gas? How many BTU burner?
http://www.homebrewtalk.com/f11/59-d...-really-91225/

I am using a 60QT Stainless Pot that was on sale at Cabelas at Christmas time and a propane burner, but I do not know the btu.

 
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Old 04-15-2009, 05:20 PM   #7
The Pol
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Quote:
Originally Posted by Brutus Brewer View Post
http://www.homebrewtalk.com/f11/59-d...-really-91225/

I am using a 60QT Stainless Pot that was on sale at Cabelas at Christmas time and a propane burner, but I do not know the btu.
The Cabellas page is gone...

So I cant really see what you have. You should be able to keep a nicely rolling boil with even a 55K BTU burner set slightly above idle in your garage (no wind)

I keep a pretty wild boil going in my keggle, 18" diamater or so... and I get 1.5gal/hr.

3 gallons is INSANE!

 
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Old 04-15-2009, 05:47 PM   #8
ewbish
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Quote:
Originally Posted by Brutus Brewer View Post
Last week I brewed my first original recipe, a pale ale. Prior to the brew day I constructed a measuring stick by pouring 1 gallon of water in my brew pot and noting the level on the piece of cpvc pipe I was using. I did this for 10 gallons of water. With the help of Promash I calculated needing 6.875 gallons of wort to the boil to reach my target volume of 5.5 gallons after evaporation. Knowing this I collected just over 7 gallons from the mash and began my 65 minute boil. When it was all said and done I had 4 gallons to transfer to the fermenter, so over the course of the 65 minute boil I lost over 3 gallons to evaporation. In case you're wondering that's almost 6 ounces per minute. I even lowered my boiling temperature to slow down the evaporation rate. Now, I know there is a shrinkage factor as the water cools, but wow, this is getting very discouraging. This was my 4th all grain brew and they have all been like this with one exception where I intentionally collected like 8.5 gallons and my boil off wasn't near what it was last week. I have been doing this inside my garage but I can't believe that this is the root cause. Any ideas?

Elevation and temp. Turn your burner down until you have a gently rolling boil, that's all you need.

 
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Old 04-15-2009, 06:15 PM   #9
Brutus Brewer
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Quote:
Originally Posted by The Pol View Post
What is the diameter of your kettle?
16" diameter
17" height
50" circumference
3418 cu/in volume = 14.8 gallons capacity

 
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Old 04-15-2009, 06:23 PM   #10
The Pol
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Quote:
Originally Posted by Brutus Brewer View Post
16" diameter
17" height
50" circumference
3418 cu/in volume = 14.8 gallons capacity
You have relatively the same size kettle and same elevation that I have.

I dont know that I could get 3gal/hr boil off.

Id turn it down until it is JUST at a rolling boil, then just a little higher.

With my electric system it is easy to get the same boil off each time, I just set the element at 70% and get the same BTUs in the boil each time.

 
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