boil-off

[Minbari]

just wondering what other people get for water boil off on thier setups. mine is always about 1.5-2 gallons an hour. just seems high.

if you can specify the size of your boil pot, will give a better comparison.

 

[Donoroto]

1.25 gallons an hour typically

 

[Herm brews]

Mine is usually around 3/4 gallon per hour.

ETA my kettle is 5.5 gallons

 

[Megary]

2/3 gallon
————-
Hour

 

[Sunfire96]

4 gallon pot loses 1/2 a gallon in an hour

 

[Ward Chillington]

About right...relative humidity seems to seems to make a difference even at only 500' above sea level. 50% took an additional quart out...1.75 g per hour.

 

[Minbari]

About right...relative humidity seems to seems to make a difference ever at only 500' above sea level. 50% took an additional quart out...1.75 g per hour.

I am at 700' I believe. I also use an exhaust hood to keep the walls from dripping.

 

[Nosybear]

just wondering what other people get for water boil off on thier setups. mine is always about 1.5-2 gallons an hour. just seems high.

if you can specify the size of your boil pot, will give a better comparison.

11 gallon pot, I get about 1 gph/3.8 lph, depending on the size of the batch and the wattage I use.

 

[Zambi]

Mine is very low. Burner is a bit small.
Less than litre per hour.
Stovetop, 10 litre pot with 7.5 litre water

 

[Nosybear]

Mine is very low. Burner is a bit small.
Less than litre per hour.
Stovetop, 10 litre pot with 7.5 litre water

That's a pretty small batch...

 

[Zambi]

That's a pretty small batch...

Yep
But I learned a lot that way. It works with my equipment and set up (got no power, just limited solar) and I get to drink beer

 

[Nosybear]

Yep
But I learned a lot that way. It works with my equipment and set up (got no power, just limited solar) and I get to drink beer

I'm brewing more 4 liter batches these days. Kind of like small batches!

 

[Herm brews]

Small batches are cool

 

[Zambi]

Small batches are cool

Sounds like a good slogan for a brewer's shirt

 

[Sunfire96]

Small batches are cool

Agreed. I brewed many a 1 gal/3.8L batch in the beginning

 

[BarbarianBrewer]

My batch size id 7.5 gal (in a 10 gal BK) and boil boil-off about 1.25 gal/hour. The boil-off is a bit more on windy days. Could your exhaust fan be causing extra evaporation? Also how vigorous is your boil? You only need a good rolling boil.

 

[GFHomebrew]

I brew in a commercial 50l keg running 3300Watt element 240v.
my boil off is 2.5lt or .6 gallons/hour.

It's just rolling along not jumping out the pot style stuff

 

[Minbari]

My batch size id 7.5 gal (in a 10 gal BK) and boil boil-off about 1.25 gal/hour. The boil-off is a bit more on windy days. Could your exhaust fan be causing extra evaporation? Also how vigorous is your boil? You only need a good rolling boil.

The hood could very well be contributing to it.
I have 4500W of heat. Its a pretty solid boil.

 

[Over The Cliff Brewing]

With the brewzilla (1500watt), it's around 1.25 gallons. Stove top small batch around .75 gallons. I can control the boil better on the gas stove top.

 

[Bubba Wade]

Boil off rate is primarily dependent on wattage or BTU of the heat source.

It takes 2731 watt-hours to evaporate a gallon of water at 212F. So if you have a 1600 watt heat source, the maximum possible boil off rate is 1.71 gallons per hour. However, that assumes a 100% heat transfer efficiency. In my experience with a 1600 watt vessel, I get a boil off of around 1.5 gallons per hour. This would be a thermal efficiency of about 88% which seems about right.