frozen yeast starter

[granda]

as an experiment i made up a 1.5l yeast starter after 24hrs i then put it into 6 seperate small pet bottles and froze it
yesterday i defrosted one and added it to a 1 gallon wine and this morning i have got a ferment going,so now i have 5 yeast starters from 1 sachet of yeast ready to go whenever i want all i have to do is defrost it

 

[seth8530]

Thats really cool, the question is tho is how long does frozen yeast survive?