Unreal Evaporation Numbers-Getting Discouraged

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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?
 
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.
 
What is the diameter of your kettle?

What are you using to boil? Electric? Gas? How many BTU burner?
 
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.
 
Brutus Brewer said:
https://www.homebrewtalk.com/f11/59-dollars-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.
Click to expand...

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!
 
Brutus Brewer said:
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?
Click to expand...


Elevation and temp. Turn your burner down until you have a gently rolling boil, that's all you need.
 
Brutus Brewer said:
16" diameter
17" height
50" circumference
3418 cu/in volume = 14.8 gallons capacity
Click to expand...

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.
 
The Pol said:
Id turn it down until it is JUST at a rolling boil, then just a little higher.
Click to expand...

That is pretty much what I did.

FWIW, My calculation from Promash indicated I needed 6.875 gallons to boil and I multiplied that by 1.04 to get 7.15 gallons to compensate for the shrinkage.

I have another section of CPVC pipe that I may use to make a new measuring stick. I'm fairly certain the other one is correct, but at this point I'll try anything.

On a brighter note I switched to a 5 gallon Igloo cooler from a 70 QT Coleman Extreme cooler for a mash tun and my efficiency increased.
 
I use a turket fryer as well and I get about 15% boiloff I have to collect a tad over 7 gallons to end up with 5.25 in the carboy...... counting trub loss and such thats about 1.5 gallons boiled away.... 3 gallins is pretty insane LOL
 
In addition to the evaporation and the shrinkage due to cooling, you have to consider the amount of wort lost to trub, the kettle dead space, wort lost to hop absorption, and wort left in equipment such as CFC's and pumps. Taking all that into account, I lose nearly 2 gallons from pre-boil to fermenter, but I would lose another gallon if I didn't tilt the kettle when draining to the fermenter.

-a.
 
michaelm said:
LOL I would prolly lose more too I am pretty aggresive getting my wort outta my kettle :)
Click to expand...

Same here. I did leave some tubing connected to my mash tun and let it drain into a gallon jug. Over the course of the boil and cooling about 1/2 gallon drained out of the tun.
 
I get about 2-2.5 gallons/hr not counting trub loss. Maybe I am boiling too hard. I crank up the heat to get it to a hard boil, and turn it down to get to my interpretation of a rolling boil before starting the timing. I dump it all, trub hops etc into the primary. I still have a primitive setup, but it works for me.
 
Did you measure the 7 gallons into the boil and the 4 gallons into the fermenter with the same system? Or was the volume into the fermenter measured using graduations on the carboy?
If you're using two different systems of measurement, there could be disagreement between them.

Being Canadian, I use the metric system for volume, the best thing I did for improving technique was to take the time and make an accurate bucket and dipstick. I weighed 1000 grams (1 liter) of room temp water at a time and made a mark on the stick from 5L to 23L (6gallons). This was plenty for me as I measure each batch sparge in a pail before dumping into the boil pot.

To measure the wort into the fermenter, I weigh each empty carboy, then weigh the full carboy and subtract the empty weight. The mass of the wort in kg divided by the specific gravity gives me my volume into the fermenter. I'm not sure what the math is to go into pounds and gallons, but I'm sure it's out there if you're interested.

Hope you solve your problem,

Cheers
 
I m not really sure about your measurement of volume. Pleasse recheck it once more. And secondly, make sure you use expanded hot water. For more details, refer the starting posts. Hope it works.
 
I live in Reno and I get pretty close to 3gallons/hr evaporation. But the climate in Reno is considered "high desert" which means low humidity (i've seen it as low as 8% sometimes) and combined with the altitude (around 4500feet), the water just flies out of the kettle. So I can believe 3g/hr.
 
mithion said:
I live in Reno and I get pretty close to 3gallons/hr evaporation. But the climate in Reno is considered "high desert" which means low humidity (i've seen it as low as 8% sometimes) and combined with the altitude (around 4500feet), the water just flies out of the kettle. So I can believe 3g/hr.
Click to expand...

This dude is in Ohio though, next door to me...

Id have to boil HARD AS HECK to get 3gal/hr. I am glad I dont, I prefer to boil 90 mins... I cannot imagine boiling off 4.5 gallons!
 
LOL to add to this I just brewed this weekend and somehow came up WAY over :) had to really crank the heat and add about 15 minutes to the boil to get it down even CLOSE to where I needed..... lol stupid humidity.... still ended up with 5.5 gallons....


think I would rather just have to top up to 5-5.25 gallons then to have to try to boil off extra... lucky I had some extra hops to throw in there :)

Just when you think you have the system dialed in..... :D

Hey Pol you need to drive over to the dayton ohio area and brew with me..... I am to lazy to go to indy I will supply the beer :mug:
 
michaelm said:
LOL to add to this I just brewed this weekend and somehow came up WAY over :) had to really crank the heat and add about 15 minutes to the boil to get it down even CLOSE to where I needed..... lol stupid humidity.... still ended up with 5.5 gallons....


think I would rather just have to top up to 5-5.25 gallons then to have to try to boil off extra... lucky I had some extra hops to throw in there :)

Just when you think you have the system dialed in..... :D

Hey Pol you need to drive over to the dayton ohio area and brew with me..... I am to lazy to go to indy I will supply the beer :mug:
Click to expand...

Heh, maybe I will take you up on that sometime. I have to say, that I have never had a variance in how much I boil off, to any real noticeable degree. I would pull my hair out, if I had any, if I couldnt get my volume naoled down.
 
Hell your only an hour. hour and a half drive away... maybe I can find the energy to come brew with you too. lol I guess its not that bad of a drive really.....


I think my major variance is from hops and such.... I am going to try the paint filtering bags and either make a sock or do the original technique of putting it around my IC and racking from inside the bag.....
 
With hops, grain and boil off, I lose just at 2 gallons. I still end up topping off with about 3/4 of a gallon of water.
 

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