We suggest that the current acceleration of the universe may be explained by the vacuum energy of a hidden sector which is stuck in a state of equilibrium between phases .
The phases are associated to a late-time first-order phase transition , where phase coexistence originates at a temperature T _ { c } \sim 10 ^ { -3 } eV and lasts until temperature falls below T \sim 10 ^ { -4 } eV .
During phase coexistence , the energy density has an effective cosmological constant component with the observed magnitude .
This scenario does not require supercooling and may arise naturally in realistic models .