I'm curious, what kind of plastic is it? There should be a number in a recycling triangle on the bottom of the bottles.
Based on
my testing, there's not a huge difference between storage in glass and PET ("1") plastic, but I'm far less confident in other types of plastic. Unfortunately, it's difficult to test other kinds, because they generally aren't clear, meaning you can't judge the color change of the nic.
A couple of points. I have read the nic storage testing you have done and I fully concur that freezing is the way to go for long term storage and that as far as color goes there seems to be no difference between PET and glass. However, without a detailed chemical analysis we do not know if anything leeched in the plastic bottles are not. I mean, if clear plastic is leeching into clear liquid, would you see it?
On the other hand, if there was any leeching, it would probably be minimal anyway as only so much can leech from a bottle before all available free atoms for leeching have been absorbed and chances are good that it already reached equilibrium during packaging and shipping anyway. If leeching was a continuous process, then eventually the bottle would completely dissolve.
Really, I do not ever see me transferring a 30ml PET bottle to a 30ml glass bottle. To me the primary reason to transfer bottles would be to break down a larger (say 1L) bottle into smaller (like 30ml) bottles in order to reduce freeze/thaw cycles on the
juice. however, if you are going to be breaking them down anyway, you may as well go ahead and use glass, just in case.
Bottom line I would store large bottles in the PET they were shipped in, in the freezer. Then when I need more I would thaw it and transfer it into 30ml glass bottles (28.32ml each, since that makes exactly 2 of my 236ml
juice @6mg/ml). Every couple of months I would thaw out a 30ml bottle to make 2 bottles of my juice, until I needed to break down another liter. This way the nic only ever gets thawed twice.
Edit: Speaking of freeze/thaw cycles, I would imagine that, just like with food, a manual defrost deep freeze would keep the juice better than a self/auto defrosting freezer since manuals do not have periodic warming cycles. I know meat and ice cream definitely keep better for longer in a manual defrost freezer.