I've heard of people going for months without opening the jar, and the myc growing fine once put in sub. I have a jar that's been fully colonized since end of June/beginning of July last year. Life happened and I was unable to do anything with it so I just left it in a makeshift incubator. I haven't noticed any in vitro fruiting so I may need to make a thread whenever I can get a tub set up and see what happens.