Now this will be controversial.

*1) depends on the ambient temperature - not recommended in 40 deg C/100+ F.

A pot of stew (or similar), if left unopened with the lid firmly on after boiling for at least 5 minutes, is likely to stay 'mostly sterile' - if then simmered/lightly boiled for 5 minutes is usually safe - unless your kitchen is next to an open sewer...

I've done that sort of thing for years, and it never affec... affec... affec... affec... affec... affec...