AbstractWe report on a special technique for high‐temperature solution growth (flux‐), which can be used to grow compounds which have only a small solubility in the flux or only exist in a small existence range (concerning temperature and concentration). By two crucibles placed into one another, an inner growth region will be separated from an outer solution region. The regions are connected by holes in the inner crucible. By this method BaSO4crystals of high quality are grown from NaNO3flux and LiCl–KCl flux. Growth experiments using this method were done with the incongruently melting high‐temperature superconductor YBa2