redox potential or oxidation–reduction potential is a measure of the summation of all of a wine’s components’ potentials to oxidize. Since wine is made up of components that are either oxidized or reduced (see oxidation and reduction), it is a system composed of many joined redox pairs. Oxidation reactions are always coupled to reduction reactions. Electrons made available from an oxidation are taken up by the compound being reduced until an equilibrium is established. The reaction with the most positive value (in which electrons are most easily accepted) will occur at the expense of reactions with lower values. Thus an equilibrium is reached from all the redox pairs and a net redox potential can be determined.