what's the recycle code on the bottom of your jug? I ask because there are some plastics that are not compatible with lye solution, such as pete #1 for example (ask me how i know!). If your jug has a recycle code of hdpe #2, though, you're in great shape. That's the kind of plastic in which i store mine.
Properly stored, lye solution will last a
very long time. As an experiment once, i stored lye solution in my hdpe #2 jug (actually a reclaimed laundry jug) for
at least 9 months or more., and it soaped perfectly fine with no issues.
Irishlass