Temperature dependent measurements of the pitch of the cholesteric phase and the spontaneous polarization of the smectic C* phase are presented for five configurations of a thermotropic liquid crystal with two chiral centers. The temperature dependent chiral properties of the two diastereoisomers (S,S)-M96 and (S,R)-M96 are additively composed by the partial contributions of the individual chiral centers, determined from the partially racemic configurations. Mixtures of the diastereoisomers exhibit a mole fraction weighted additivity of the chiral properties.