The acid in cider will aggressively dissolve any iron or copper it comes into contact with, giving it a blue/green color and corresponding taste. One thing I ra

The acid in cider will aggressively dissolve any iron or copper it comes into contact with, giving it a blue/green color and corresponding taste. One thing I ran into with my old press was some paint finish flaking off, exposing the iron beneath- is it possible that you had something similar, allowing inadvertent iron exposure? For this project, every single screw or sheet of metal that touched the cider is made from food-grade stainless steel to prevent this issue.