Need some input on double batching

[unkeldunkel]

I recently installed some 30bbl fermenters and I have never double-batched a 15bbl brew before. I am looking for some input on pitching procedures. What are the most widely used methods, aerate both brews? double pitch on brew 1 or does the yeast reproduce enough that the count will be sufficient for brew 2? We have the ability to double batch on the same day with only 4 hours between K.O.s but don't want to rely on doing it all the time. Any advice would be appreciated.
Thanks,
Sean H.

[gabewilson50]

http://www.probrewer.com/vbulletin/showthread.php?t=3226&highlight=multiple+batch+brew

[jazzmac]

We have 40bbl fermenters. We do a 2 15 bbl batches in one day followed by a 10 bbl the next day. Been doing it for 10 years that way with no problems. We only oxyginate the first batch.

[Jim Lieb]

When I double batch, I usually do it on consecutive days. I only oxygenate the first batch and add yeast nutrient to the first batch. I only pitch enough yeast for the first batch, it will reproduce enough for the second batch. If you are going to double batch on the same day I would add more yeast than you would for a single batch.

Jim Lieb