Whirlpooling

[Mantis]

The table my kettle sits on has a very slight incline, so I place the tap on the high side and whirlpool with a slotted spoon.
I give it a quick stir and leave for a few minutes. I think this gives it time for the updraft of thermal heat to subside. Then give it a quick whirlpool and leave for 30min
Always get a good cone and because the pot is on a slight slope the cone forms off centre and away from the pickup
I can usually get all the wort out if I slow the runoff when the level gets down to the cone

 

[Thirsty Boy]

Things I have learned about whirlpooling

1- too much shit in the bottom of your kettle messes it up

2- I never made it work in a converted keg... it should, but I couldn't get it too.

3 - convection currents ruin it. You need to let your wort "sit" for a bit till the residual heat in the pot and your burner stops turning it over with heat convection. Then you whirlpool and rest for 20mins after you stop stirring.

4 - the faster you spin, the better the results. The forces that make a whirpool happen, are friction forces as the spinning slows down. So - if you get it spinning fast, so it takes a long time to "wind down" ... then those forces will be in play for longer and will work better. I no longer stir with a spoon... I have a jigger that goes on the end of my power drill. That wort bloody well SPINS with a vortex to the bottom of the kettle. I build the speed up slowly and I don't try to get it to go faster after the full vortex, so it isn't frothing/cavitating and HSAing the buggery out of my wort.

5 - I have performed a total of 1 ... count em 1 ... truly good whirlpools. Today in fact - my new flat bottomed 60L kettle. 10mins settling, spin with drill, rest 15-20mins - drain to cubes. cone piled up in the middle 3 inches above the outlet.. clear and clean wort at the edges - no more than 500ml unrecoverable wort and very very clean wort into my cubes.

I am chuffed - I love it when a plan comes together and the above points constitute said plan.

TB

edit. Mantis' point - when your wort level hits the top of the cone, slow down your run-off. If the wort level is dropping faster than liquid can drain from teh cone, the cone collapses. Go slowly and the cone will retain its integrity and you will recover more wort (theory not personal experience.. well, just the once anyway)