Collected pollen stays viable for around a year if it is thoroughly dried and frozen with a desiccant, and only weeks at room temperature. Handling steps, including cutting it with flour to extend coverage, are described at https://potentthcseeds.com (https://potentthcseeds.com). Any moisture in the container kills it faster than the cold does. Thawing must happen slowly in a sealed jar, otherwise condensation ruins the whole batch.