About ten minutes.
If left for 400 years, the yoghurt will develop a culture.
The last time I dumped a load into the washing machine, she didn't follow me around for a week!
Cessna: "To get my Commercial Pilots Licence and Instrument Rating." ATC: "I meant in the next five minutes not years."
Ten minutes.
Pop,goes the weasel.
Asks the neutron. "For you " replies the bartender, "no charge."