If I recall, the folks in St. James Parish, Louisiana unpack, air and repack after the first 3 weeks, then repeat this at 3 week intervals a time or two more. They let the batch run for as long as 9 months, and do the unpacking routine a few more times at wider intervals.What is the preferred schedule for unpacking and repacking the leaves during a 3-month cure?
My impression (mine alone) is that unpacking and repacking serves only to darken the color of the batch, but has little if any impact on the final flavor and aroma. Exposing the pressure-damaged leaves to oxygen serves to oxidize (darken) the color of the nicotine uniformly.
I've run a couple of batches with no unpacking at all. It comes out at the end of the run appearing much lighter, but once exposed to air it darkens quite a bit. Another approach I've tried is periodically releasing the pressure on the mass of tobacco, allowing the dark surface juices to penetrate more deeply, then reapplying the pressure the next day. This causes at least the upper and outer portions of the wet mass of tobacco to darken, but does not fully infuse the deeper areas of leaf.
Recommendation: Air it once, after the first 3 weeks, then just keep it under pressure the remainder of the time. Don't add too much water, when maintaining the liquid seal, since Pichia anomala yeast need a highly concentrated liquid in order to thrive and supplant less desirable microbes (like E. coli, which imparts the initial "barnyard" aroma early in the process).
Bob