I have started doing mash in a bag as it seems to work very well for relatively small batches. The biggest kettle I have can only produce about a 6 gallon batch. I've read different opinions about sparging the grains in the bag. I was wondering if it would be possible to boil the hops in a separate kettle while the grains were mashing in the bag in the first kettle. Then I could use the hopped water to sparge the grains and top up the first kettle to the boil volume. Is there any scientific reason why this would not work or be inefficient? I've also read about immersing the bag of grains in the second kettle to allow the sugars to rinse out like a big tea bag. I'm just starting out so any constructive comments would be very helpful.