Experimental distinction between neutrinos and antineutrinos How can we experimentally distinguish left-handed neutrinos from right-handed antineutrinos when we do not know a priori their creation process (for example in the case of cosmological neutrinos)?
 A: Lepton number is conserved in charged-current interactions (and, so far as we know, everywhere else). When a matter neutrino undergoes charged-current scattering, by emitting/absorbing a $W^\pm$, it creates a matter electron with negative charge. But when an antimatter neutrino undergoes charged-current scattering, it creates an antimatter electron with positive charge.
The chiral restriction of charged-current interactions, to left-handed particles and right-handed antiparticles, is an experimental result which requires you to distinguish matter from antimatter independently. The first historical result was published by Lederman and collaborators in 1957; it’s the article on the next page after the Wu et al. discovery of parity-violating oriented decays. Without re-reading, my recollection is that Lederman was able to measure the polarization of the muons and electrons produced in pion decays, and set limits on the neutrino polarization from there.
A: I think you partly have answered question yourself, but wiki about neutrino says it all :

neutrino $\to~~~~~$ chirality: Left, $~~$weak isospin: $\boldsymbol {+}\frac 12$, lepton number  $\boldsymbol{+}1$


antineutrino $\to$  chirality: Right, weak isospin: $\boldsymbol {-}\frac 12$, lepton number $\boldsymbol{−}1$

So you can distinguish them by all three properties combined.
