The key to yeast management is keeping the yeast healthy. High hygiene standards are a given but you need to crop the yeast while its healthy and store it between 3 and 5 deg C. Too warm and it will respire and die, too cold it will freeze and die. Not good. Use it within 5 days, yeast is not happy in storage, it gets stressed as its sitting in a toxic environment (CO2 and alcohol) without any nutrition.