A method for producing an optical fiber base material ingot comprising depositing a soot on a starting core member having a central axis and subjecting the soot to dehydration and vitrification by sintering to form an ingot, mounting the ingot in a cylindrical grinding machine having a rotation axis so that the central axis of the core member is generally in line with the rotation axis of the grinding machine, and grinding the ingot in the grinding machine, the mounting of the ingot in a cylindrical grinding machine including the steps of initially mounting the ingot in the cylindrical grinding machine so that the central axis of the core member is generally in line with the rotation axis of the grinding machine before any grinding of the ingot is performed, performing a rough grinding of the ingot, adjusting the position of the ingot within the grinding machine so that the central axis of the core member is again generally in line with the rotation axis of the grinding machine, and subsequently carrying out further grinding of the ingot.