What's your E-Keggle boil off rate?

[CanAm]

Next brew day will be the first on my all electric system - very excited! But I'll be doing a 5 gallon batch (instead of my usual 10). I've done a 5 gallon once before in the winter and it's so steamy I can't get a gauge on boil off rate! I can hardly see into the keggle. I ended up adding more water at the end to decrease my OG because my propane burner was set too high. Add to this I'm using a new heating method and I'm stumped.

So help a new E-Brewer out with your keggle boil off rate! Please include:

1. Batch Size
2. Element Wattage
3. PID percent you boil at
4. Other important fact(s)

Thanks a lot!

 

[Brettomomyces]

I collect about 13.25g, boil down to 11'ish

2 layers of reflectix insulation

5500w ULWD camco

Auber PID, 68% is my go to for a good boil. Boil off is about 1.25/hr, I do 90 min boils

I'm also at 5400 ft, so I boil about 201-202F

 

[ChuckO]

I have found that the boil off rate is more dependent upon the diameter of the pot than upon the volume in the pot.

I boil off about 1.2 gal/hr in a 13" diameter kettle with a 5500w element at about 70% duty cycle. It doesn't matter whether I am making a 5 gal. batch or a 10 gal. batch. The humidity level also plays a small part, but the most important thing seems to be whether I have a rolling boil, or a violent boil.

 

[augiedoggy]

I have found that the boil off rate is more dependent upon the diameter of the pot than upon the volume in the pot.

I boil off about 1.2 gal/hr in a 13" diameter kettle with a 5500w element at about 70% duty cycle. It doesn't matter whether I am making a 5 gal. batch or a 10 gal. batch. The humidity level also plays a small part, but the most important thing seems to be whether I have a rolling boil, or a violent boil.

I agree to a point,I believe this is due to more surface area for offgasing the steam (if thats the right use of the term).
I get 1 gallon per hr boiloff with my 4500w element set at 65-70% manual mode and 6.5 gallons because the boil if not quite as vigorous with 11.5 gallons in the pot I have to raise my setpoint to 70-75% to obtain the same...

the other side to this is wider pots are generally less efficient at holding the heat in the liquid for the same reason as well as relestate around the element and distance it can travel away from the central heat source around vs above where the heat travels best.. so that effects things as well...

 

[dyqik]

The other big factor along with exposed surface area in the boil-off rate is air movement due to ventilation or wind blowing over the pot that removes the saturated air and replaces it with drier air that can take up more moisture.

 

[Snicklefritz]

1.2 gal/hr is my number. I usually run about 60% cycle.

 

[CanAm]

Thanks for the responses. I'll plan accordingly.

 

[BitterSweetBrews]

I just built an electric kettle with a 13.2 gallon keg. I did a test with water and boiled off 2 gallons in 60 minutes at 100% with a 5500 watt element. I think I'll do another test at 60% to check.

 

[hio3791]

As a new E-brewer, I urge to run a water boil to test your equipment and help you get a "feel" for things. Your system specific properties will be different than everyone else.

I ran a 10 gal water test, once the PID was trained, I ran a 2 hr boil test. I measured the boiloff rate and wanted to make sure there were no operational issues with my "new" equipment.

 

[ryan_george]

I generally aim for 10 L/hr (~2.6 gal/hr) with my system.

~20 gal batches, 10 kW power run at ~65%, 24" diameter pot (non-insulated), with the lid open about 8" or so.

 

[kal]

Typically 14-15 gallons pre-boil (though this doesn't matter or affect boil off rate).

5500W element run typically at 85% duty cycle.

Blichmann Boilermaker G1 20 gallon.

I boil off 1.9 gallons/hr.

Kal

 

[tjpfeister]

1) 13.5 boiled down to 11.0 (10.5 into fermenters)
2) 5500w
3) I use a pulse width modulator seperate from my PIDs for boiling. The knob is marked at the 2/3 position (to achieve 6qrts boil-off) but the measured average amperage of 18a (23 max) divides out at 78%