Drop the metal closer to the water.
When you drop molten metal from a reasonable height surface tension
makes the metal form spheres.
There was a shot tower in a Melbourne shopping centre that always
fascinated me. The molten lead would be poured through a grate at
the top of the tower, the pellets would fall, forming spheres and end
up in a pool of water. If the pellets were dropped closer to the
water they wouldn’t form spheres.
Regards Charles A.