Do enantiomers always have different physical properties?
In fact enantiomers should have identical chemical and physical properties. There is of course 1 proviso!
Enantiomers should have identical properties in an achiral environment. This makes sense on the basis that enantiomers are the same molecule, and are related by a mirror plane. Once we introduce chirality into the environment, for instance another chiral molecule or plane polarized light, the enantiomers may be differentiated both chemically and optically.