Vigorous Boil Reduces To Gentle Boil

[Thirsty Boy]

Steve,

I find the same thing happens to me (three ring cast iron burner)

At the start of the boil, once it gets going, I only need the large outside ring to maintain a rolling boil, but through the boil I have to constantly tweak the burner and by the end of the boil, I usually end up having to run the two biggest rings to maintain the boil.

Its a PITA because I cant get a nice consistant evaporation rate figure for my system, this boil I might have let run a little hotter than the last or visa versa, I really just want to be able to whack the thing on and leave it alone, so that I have consistancy.

Keep me updated if you work out whats going on.

Thirsty

 

[bear09]

Steve,

I find the same thing happens to me (three ring cast iron burner)

At the start of the boil, once it gets going, I only need the large outside ring to maintain a rolling boil, but through the boil I have to constantly tweak the burner and by the end of the boil, I usually end up having to run the two biggest rings to maintain the boil.

Its a PITA because I cant get a nice consistant evaporation rate figure for my system, this boil I might have let run a little hotter than the last or visa versa, I really just want to be able to whack the thing on and leave it alone, so that I have consistancy.

Keep me updated if you work out whats going on.

Thirsty

This is strange. I use a 3 ring with a 9kg bottle and have never had this problem. My reg is NOT adjustable. No icing no inconsistent boils.

Interesting.

 

[losp]

are you talking about it starting to bubble less? if this is the case maybe i am brewing wrong! i usually heat it till it bubbles, and stir it a bit to stop it overflowing and then i turn it down to the point where it is boiling but not bubbling like crazy (water just moving around) and keep it like that for 90 mins.... wrong?

 

[thunderchild]

are you talking about it starting to bubble less? if this is the case maybe i am brewing wrong! i usually heat it till it bubbles, and stir it a bit to stop it overflowing and then i turn it down to the point where it is boiling but not bubbling like crazy (water just moving around) and keep it like that for 90 mins.... wrong?

You will find that the more vigouous the boil the better break you will achieve and a clearer beer at the end.

 

[losp]

sorry i am a noob to AG. but by break do you mean, hot break? if so, doesnt this happen before the boil? (sorry for hijack)

edit: sorry just re read it. more power next time. cheers.

 

[Steve]

sorry i am a noob to AG. but by break do you mean, hot break? if so, doesnt this happen before the boil? (sorry for hijack)

edit: sorry just re read it. more power next time. cheers.

You didnt hijack losp, this thread is two years old. Anyway you want a vigorous bubbling boil, not just liquid slowly moving around.
Cheers
Steve

 

[rosswill]

Interesting thread.
I too have experienced the iceing up, and reduced output.
I have a Rambo wok burner with a high pressure reg. Works a ripper, however as the bottle empties, it ices up and the flame reduces to the stage where the wort goes off the boil. A quick shake of the bottle rejuvinates the flame, only to drop off again. Change bottles, and all is good again. The only problem is though the bottle is not empty. I stick it on the BBQ and have since cooked 3 meals, and no sign of running empty. I have put it down to the emptying cylinder not having enough grunt to force its way through the high pressure regulator.

 

[Fourstar]

Interesting this thread somehow got revived from the depths of hell! Nevermind, i have a similar issue as Thirsty Boy had back in '07 which is pushing me to the edge to be completly honest. Im sick of inconsistency with the boil and i have a feeeling the poor break formation because of this is a possible cause to my consistent haze issues ive been having recently. Im thinking of just packing it in and buying a NASA with an adjustable reg. :angry:

I use a bog standard BBQ reg and a 3 ring rambo/cast iron jobby. Some days i could be boiling out in the open air, random wind and the vigour of the boil is that crazy i have to turn off the center ring. Other days i could be boiling in my little tin shed (3X2M) and all three rings going balls to the wall and struggling to even get to a boil with the lid 1/2 on the kettle! :blink:

The only issue i can forsee with the little shed is O2 uptake ability and airflow as i get a little extra orange flame. If i try and drop the pressure back so it just gets to blue the kettle never gets to the boil unfortunatly. The other PITA is if i just swap a regulator to an adjustable one for the RAMBO (i'd assume i'd also need to bore out the burners as well) im going to have to build something to adjust the height of the kettle above the burner so i get a decent flame.

Such a pain.

 

[Gopha]

My two bobs worth, I think you will find the problem is directly related to the LPG bottle and the demand for gas (volume).
The gas bottle needs to vaporise the liquid in the bottle to a gas, it does this by absorbing heat from the surrounding atmosphere using the surface area of the bottle below the liquid level.
Low liquid levels and low temps result in poor vaporisation, hence a drop in pressure and a drop in volume.
Cheers