Freezing is dangerous due to condensation issues. All tea is becoming
stale the minute it is produced. Fresh tea packed at source in
mylar/foil and not repacked here in the US is probably the best method
overall. Nitrogen flushing is new to tea and not available to many tea
packers. Once opened, the benefit is lost as mentioned above. Once
opened it is best to drink the tea as soon as practical. Know your
supplier!

t4u