I have often heard people talking about the viability of pitchable liquid yeast either in a vial or smack pack dropping over time. This effect is greatly accelerated with increased temperature, so storing the yeast cold without freezing will slow down the drop in viability.
Does the effect of dropping viability mean that if the liquid yeast has to travel a long distance to reach me it would be better using a dried yeast? How is the liquid yeast generally transported overseas? Is it refridgerated?
To make the example a bit more specific White labs produces yeast in California and I buy it online from a homebrew shop in the UK. Would dried yeast perhaps be a better option?