A quick history lesson about myself:
About a year ago I built a 2 tier, 3 keg system with a direct fired MLT for doing 10 gallon batches. I used 1 pump, and set myself up for either batch or fly sparging. The system has worked fantastic! I have been able to get my 10 gallon batches to under 5 hours from pulling water to cleaning up. About 6 weeks ago I got the idea to set up my "extra" 36 gallon X-treme cooler to do 10 gallon hybrid sparges, and do a "double batch." My idea was to offset 2 batches by about 30 minutes, and have my HLT do double duty - mashing and boiling. I heat my first strike water in the keg MLT and the second (cooler) strike water in the HLT. Start the first mash in the MLT, and 30 to 45 minutes later add the second strike water from the HLT to the cooler and begin the second mash. Sparge water for the first batch is then added to the HLT and heated. After the first mash is done with a batch sparge, the second sparge water is heated in the HLT. The MLT is cleaned out, and used as the boil kettle for the second batch. The second mash is sparged using the hybrid technique into the MLT (now a boil kettle) and boiled. The first batch is cooled and put into carboys just in time to get the second batch cooled and into carboys. Total double batch time is about 5 1/2 hours. Phew, make sense?
Anyway, making a batch of beer has always been relaxing. However, these double batches are sure kicking my butt! My cousin, who is new to brewing, has served as my assistant for both double batches I have done (Red+Haus Ale, IPA+Haus Ale) and I probably wouldn't have survived without him. It is amazing how doubling the work with only an extra 45 minutes wears you out. I only sat down for 3 minutes out of the 5 1/2 brew evening this weekend. If anyone else wants to attempt this, be aware that it is a mad scramble to get everything done on time, and keep up the pace. Also, the 36 qt cooler is really pushing the envelope for 10 gallon batches. Mashing Haus Ale per Edwort's recipe with a 1:1 ratio leaves not 1/64" of headspace in the cooler!