Single crystals of the superconductor YBa2Cu3Oy have been grown from a mixture of solid phase YBa2Cu3Oy and liquid phase silver. Crystals with a thickness of up to 1 mm along the c axis can be obtained when the mixture is soaked at 1005 °C for more than 8 h. Silver melt enhances the peritectic partial melting of the YBa2Cu3Oy solid phase, and induces the solution and reprecipitation process during sintering at 1005 °C. Stacked plate-like YBa2Cu3Oy grains grow through a coalescence process. Crystals are heavily twinned after 20 h of O2 annealing at 500 °C. They exhibit a sharp superconducting transition with an onset temperature of 93 K in zero field.