Can the quality of olive oil be tested at home?
The urban legend claiming that the quality of olive oil can be tested by placing it in the refrigerator is exactly that – a myth! The quality of olive oil cannot be established in this way.
The oil’s tendency to crystallize (or not to crystallize) is due, among other things, to the olive from which it was produced. Tests to determine the quality of the oil are complex, and the only way its purity can be tested is by a qualified laboratory.