They are probably talking about pressing when going from primary to
secondary. During primary, the fermentation breaks down the crushed grapes
and you get a lot of free juice with solids in in. When you fill your
press, the juice runs through and is called free run juice. Then you press
the solids. Some people keep free run separate from pressed juice. I do
not.

If you are making white wine and are pressing grapes that have been crushed
but not fermented you will have much less free run juice and it will take
more fillings to press out the same amount of final juice.

Don't make the mistake some make and try to press whole grapes. It don't
work! They must be crushed first.

Ray

"Don S" > wrote in message
om...
> I think google ate my posting...
>
> So a 25 cm in diameter by 33 cm high (usuable height of 13 in)
> press is adequate for a couple of 23l carboys of wine. When
> someone says one press will fill a 23l carboy are they filling
> the press with grapes and completely pressing out or are they
> pressing one load, opening the press up again and adding more
> grapes and pressing again? In other words, the first would be
> one full load completely pressed, the second would be a couple
> of loads squeezed down and more added before fully pressing.
>
> Don