Finally a good measure of boil off - normal?

[TravelingLight]

I did my second beer yesterday. Hopefully my last all extract beer. This was also my first beer since I etched my kettle with volume markings. I started with 7 gallons of water. After the 60 minute boil, my post boil volume was just under 6.5 gallons. So I lost just over a half gallon. I thought I would have lost closer to a full gallon. Didn't bother me though because it gave me more beer to put in the fermentor to account for beer lost to dry hopping. Anyone else only lose about a half gallon or so? I just really want to dial in my efficiency and know my process inside and out so I'm seeing what kind of efficiencies others are getting.

 

[kev211]

Were you using a propane burner? Or stove top? I know it may sound stupid, but you would be surprised... Did you leave the lid off?

I tend to lose closer to 2 gallons, but I use an 185,000btu burner that puts out serious heat/boils off a lot of liquid. But regular gas stoves tend to put out only ~12,000btu's on the higher end. So really cant boil as much off

 

[TravelingLight]

Were you using a propane burner? Or stove top? I know it may sound stupid, but you would be surprised... Did you leave the lid off?

I tend to lose closer to 2 gallons, but I use an 185,000btu burner that puts out serious heat/boils off a lot of liquid. But regular gas stoves tend to put out only ~12,000btu's on the higher end. So really cant boil as much off

I was using a propane burner, just a standard one burner turkey fryer. My big two jet burner was out of commission. I keep the lid mostly on while it is heating up, but once I start my 60 minute boil and start adding my fermentables and hops the lid is off the rest of the way.

 

[kev211]

I was using a propane burner, just a standard one burner turkey fryer. My big two jet burner was out of commission. I keep the lid mostly on while it is heating up, but once I start my 60 minute boil and start adding my fermentables and hops the lid is off the rest of the way.

Well thats bizarre, cuz I know those turkey fryers throw some serious heat. I see you live in SC, was the humidity high? I know weather can affect boil off rates, I just dont know the exact numbers. But if it was humid to begin with boil off rates tend to be lower, since its hard to soak more liquid into the air.

That being said, what was your boil like? Vigorous? Or rolling? Maybe do two test batches (using just water) at rolling and vigorous and see what the outcome is

 

[TravelingLight]

Well thats bizarre, cuz I know those turkey fryers throw some serious heat. I see you live in SC, was the humidity high? I know weather can affect boil off rates, I just dont know the exact numbers. But if it was humid to begin with boil off rates tend to be lower, since its hard to soak more liquid into the air.

That being said, what was your boil like? Vigorous? Or rolling? Maybe do two test batches (using just water) at rolling and vigorous and see what the outcome is

Humidity was relatively low yesterday, around 40% I believe. I guess I would classify it as a nice even rolling boil. Nothing crazy, it held around 210-212 degrees the whole way IIRC.

 

[BBA]

I did my second beer yesterday. Hopefully my last all extract beer. This was also my first beer since I etched my kettle with volume markings. I started with 7 gallons of water.

For the sake of clarity, was it at "7 gallons of water" before you added your extract, or after?

 

[theseeker4]

Humidity was relatively low yesterday, around 40% I believe. I guess I would classify it as a nice even rolling boil. Nothing crazy, it held around 210-212 degrees the whole way IIRC.

Was it 7 gallons at 60 degrees, and 6.5 gallons post boil at 212 degrees? Or were the measurements taken at the same temperature? Seems very little boil-off to me....

 

[LandoLincoln]

I did my second beer yesterday. Hopefully my last all extract beer. This was also my first beer since I etched my kettle with volume markings. I started with 7 gallons of water. After the 60 minute boil, my post boil volume was just under 6.5 gallons. So I lost just over a half gallon. I thought I would have lost closer to a full gallon. Didn't bother me though because it gave me more beer to put in the fermentor to account for beer lost to dry hopping. Anyone else only lose about a half gallon or so? I just really want to dial in my efficiency and know my process inside and out so I'm seeing what kind of efficiencies others are getting.

Water shrinks about 4% when it goes from near-boiling to room temperature, so if you read the first measurement at room temperature and didn't cool the wort before taking the second reading then you probably lost closer to 3/4 of a gallon instead of just a half gallon.

 

[TravelingLight]

Ahhh thanks guys. Didn't even think about all that. The 7 gallons pre-boil volume was just water. Basically what the water level was at when I fired up the burner to heat it to boiling. And the post boil volume was after I chilled. Didn't even think about that! Feel dumb man.