I've kept my liquid in amber vials in a dark place at around 73 degrees Fahrenheit for more than a year before, and my material was still perfectly fine.
“The most compelling insight of that day was that this awesome recall had been brought about by a fraction of a gram of a white solid, but that in no way whatsoever could it be argued that these memories had been contained within the white solid. Everything I had recognized came from the depths of my memory and my psyche. I understood that our entire universe is contained in the mind and the spirit. We may choose not to find access to it, we may even deny its existence, but it is indeed there inside us, and there are chemicals that can catalyze its availability.”