Again to my question and somewhat to the previous poster's... Why not just hoist the bag, start your stirrer and boil, and be sparging at the same time over the pot. From my understanding of what your are trying to do seems A LOT more time consuming to do. Having to hoist the bag, let it drain, then move it to another bucket to sparge, to then pour the runnings back into the BK, and then to have to clean an extra piece of equipment.
Sorry, I don't see how this saves you any time. I also do not see the purpose, unless you are adding a drastic amount of points (sugars) more to your pre-boil gravity. I have done large 11 or 16 gallon batches and just hoist, sparge over the kettle, and then boil. I never got under 75% effic.
I appreciate your questions.
I am not sure I am following your questions/suggestions though.
My keggle can hold a fuzz over 16 gallons total and with 13 gallons of water and 20-ish pounds of grain that leaves me with about 15 gallons total volume.
After I pull the bag out I am at about 10.5 gallons and need to squeeze the bag and add 3 gallons to get my to by pre boil volume of 14 gallons.
I consistently get 80% efficiency using this process.
My current process/thinking is I mash for 60 minutes total, that is typically a step mash schedule, maybe 2 or 3 temps, ending at 165, with my stir motor going the whole time (yes I could shorten that mash time but for now I have consistent results and good beer so I am not changing it)
After 60 minutes I pull off the stir motor and hoist the bag just long enough to get the bulk of the wort to stop draining, which is only a minute or 2 then put the half wet bag into my sparge bucket.
I then put the stir motor back on and start the ramp up to Boil.
While the boil ramp starts, I press the grain a bit and add the 3 gallons of sparge water, in repeated steps currently since my bucket is too small with more than 20 pounds of grain.
As the ramp up is going I add the sparge water in a few steps over the 30 minutes time it takes to go from 165 to Boil.
So I currently sparge in parallel as the boil is ramping up.
If I just let the bag hang for 15 minutes and tried to do some sort of sparge over the hanging bag it would result in the added 15 minutes to my process since I would not start the boil until I pulled dripping bag away from the boil kettle.
Chris - I can not hang the bag and run the stir motor at the same time, the wort would run all over the stir motor.
I need to run the stir motor as the wort is ramping up to boil because I have burned 2 batches when not doing so.... the element is full on and the dust in the wort will stick to the element and burn with out the stirring.
I do get some points added in sparging this way but that is not really why I do it, It is the only way I get my boil started asap and still get some sugar out of the grain.
If I had a bigger bin for sparging I could add my 3 gallons sparge water over the grain bag at once, let it drain and add the 3 plus gallons into the kettle at one time.
The only other thing I see is to do what you bring up and add more more grain so I just pull the wet bag and add the plain water right to the kettle to save some time and clean a few less buckets, but rinsing out 2 vs 3 buckets is not much of savings and they dont have to be sanitized regardless.
So there it is...
Keep the comments coming.