By the way, an other question. I have a mesh bag that is suppose to
sit inside the press but for what ? I also have a plastic bag that
goes on the outside to avoid splashing juice over the place but I
don't understand the inner bag purpose ?

If you made white wines you'd know! White must is very slippery. When you
squeeze it too quickly it tends to shoot _geysers_ of must between the press
slats. A screen keeps that from happening. To be really effective the
screen needs to be coarser than window screen and made out of much heavier
gauge stainless steel wire.

Tom S