Hmmm... the sediment sounds suspicious to me. Does it also have an 'off' smell?
The castor I buy fom the healthfood store in 2 lb. bottles is always a clear, light golden color and has never had sediment in it. It also lasts a long time. From all I've read, castor is slow to go rancid and typically lasts from between one to two years.
Does your jug say how the castor was extracted?
IrishLass