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

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

On Tue, 23 Mar 2004 00:43:21 GMT, "Ray" > wrote:

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

Why? what happens?




email: dallyn_spam at yahoo dot com
please respond in this NG so others
can share your wisdom as well!

"Dave Allyn" > wrote in message
...
> On Tue, 23 Mar 2004 00:43:21 GMT, "Ray" > wrote:
>
> >Don't make the mistake some make and try to press whole grapes. It don't
> >work! They must be crushed first.
>
> Why? what happens?

Your juice yield will be pitifully low because many of the berries will
remain unpopped.

Tom S

Dave Allyn > wrote in message >. ..
> On Tue, 23 Mar 2004 00:43:21 GMT, "Ray" > wrote:
>
> >Don't make the mistake some make and try to press whole grapes. It don't
> >work! They must be crushed first.
>
> Why? what happens?
>
>
>
>
> email: dallyn_spam at yahoo dot com
> please respond in this NG so others
> can share your wisdom as well!

Think about it... If you haven't crushed them, they're going to act
like little water balloons when pressure is applied, and you're going
to lose and waste alot of the juice. Plus you'll still have over 50%
of them with the skins still intacked and not broken. Crush first,
press later.

RogerK

"RogerK" > wrote in message
om...
> Dave Allyn > wrote in message
>. ..
> > On Tue, 23 Mar 2004 00:43:21 GMT, "Ray" > wrote:
> >
> > >Don't make the mistake some make and try to press whole grapes. It
don't
> > >work! They must be crushed first.
> >
> > Why? what happens?
> >
> >
> >
> >
> > email: dallyn_spam at yahoo dot com
> > please respond in this NG so others
> > can share your wisdom as well!
>
> Think about it... If you haven't crushed them, they're going to act
> like little water balloons when pressure is applied, and you're going
> to lose and waste alot of the juice. Plus you'll still have over 50%
> of them with the skins still intacked and not broken. Crush first,
> press later.
>
> RogerK

Crushing first and then pressing is certainly a more efficient process, but
grapes can be pressed without crushing. It just takes longer and is more
work. Many premium white wines are made by whole cluster pressing, and
grapes are not crushed when making Champagne.
lum

Agree with the above and I have even heard of people getting small yields so
they keep putting more and more pressure on until the pore press blows up.

Ray

"Dave Allyn" > wrote in message
...
> On Tue, 23 Mar 2004 00:43:21 GMT, "Ray" > wrote:
>
> >Don't make the mistake some make and try to press whole grapes. It don't
> >work! They must be crushed first.
>
> Why? what happens?
>
>
>
>
> email: dallyn_spam at yahoo dot com
> please respond in this NG so others
> can share your wisdom as well!

> 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.

I assume you are talking about pressing *whole grapes*. In which case:

Even if all your grape matter was 100% liquid/juice (which they are
not of course), you can't get 46 L (2*23) from that kind of volume
press/grapes *from a single pressing*:

(usable height = 13 in = 2.54 * 13 = 33.02 cm)
pi*r^2*h = pi * (25/2)^2 * 33.02 = 16.2 L

So even if all your grapes were actually liquid which all got
extracted, you'd still only get 16.2 L out of that single pressing.

Grapes usually yield about 600-700 ml/kg juice, so you'd need a press
which could fit about 65-77 kgs in it to be able to press out 46 L in
a single pressing operation.

Ben

Anyone want to take a stab at answering the question on
press technique. No BS I've asked the question three times
in here without an answer. It seems to always immediately
jump off topic.

Don

> 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

You can do it that way but there really is no need to. If you are going to
go to the trouble of backing off the pressure and taking the piston out, you
might as well dump the pulp and start over. At least that is my thoughts.

Ray

"Don S" > wrote in message
om...
> Anyone want to take a stab at answering the question on
> press technique. No BS I've asked the question three times
> in here without an answer. It seems to always immediately
> jump off topic.
>
> Don
>
> > 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

"Don S" > wrote in message
om...
> Anyone want to take a stab at answering the question on
> press technique. No BS I've asked the question three times
> in here without an answer. It seems to always immediately
> jump off topic.
>
> Don
>
> > 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

Don,
If your question refers to press technique, I'll take a stab at it.

The following procedure works well with small, vertical basket presses.
(1) Fill the basket, add the top plates, blocks and press head.
(2) Apply a small amount of pressure until the liquid flows.
(3) When the flow decreases, increase the pressure, but don't exceed about
50 psi. Ratchet type basket presses can produce high pressures, but high
pressures often produce harsh, bitter wines.
(4) Excessive amounts of foam between the basket slats indicate the
pressing is being done too rapidly.
(5) When the flow nearly stops, disassemble the press, crumble the press
cake and repress.
(6) For most grape varieties, crumbling the press cake two or three times
will be necessary to produce dry pomace.

lum

Lum,
So a #25 press would be adequate for one or two 23l carboys?
What's the approx. diameter of the press in your, the one in
the pic at the end of Ch 6?

Don

Don,

Confusion arose in the last thread ("press size") as to whether you
were talking about whole cluster pressing or crushed grape pressing.
There is a significant difference (both in terms of quantitative AND
qualitative extraction).

On press technique:
> > 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?

They are most likely using crushed grapes, which already have much of
their juice released. This means that the crushed grapes added to the
press already has some free run in it which can run out of the press
without any actual pressing action. In this way, volumes of crushed
grapes larger than the actual capacity of the press can be added to
the press before actual pressing begins.

> > 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.

That is not normal practice.

> So a #25 press would be adequate for one or two 23l carboys?

Yes. Using crushed grapes you could certainly manage that with a 25
diam x 33 cm height press.

Ben

> Confusion arose in the last thread ("press size") as to whether you
> were talking about whole cluster pressing or crushed grape pressing.
> There is a significant difference (both in terms of quantitative AND
> qualitative extraction).

I didn't know there was a thing called whole cluster pressing.
I assumed you crush and press.



> > > 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.
>
> That is not normal practice.

The first or the second?



>
> > So a #25 press would be adequate for one or two 23l carboys?
>
> Yes. Using crushed grapes you could certainly manage that with a 25
> diam x 33 cm height press.

That's good enough for me, I may go with 25 cm square so it
will have a slightly larger volume. I'll let the size of the
slats set the final size - whatever number of whole slats is
close to 25 cm per side with a mm or two gap between them.

Thanks everyone.

Don

"Don S" > wrote in message
om...
> Lum,
> So a #25 press would be adequate for one or two 23l carboys?
> What's the approx. diameter of the press in your, the one in
> the pic at the end of Ch 6?
>
> Don

Don,
On that press, the ID of the basket is 12 inches and the height is 19
inches.
lum

> > So a #25 press would be adequate for one or two 23l carboys?
> > What's the approx. diameter of the press in your, the one in
> > the pic at the end of Ch 6?>
>
> On that press, the ID of the basket is 12 inches and the height is 19
> inches.

Great Lum thanks. I make it out at about 29 liters if we
say there are about 16 inches of useable height.

(12/2) inches = 15.24 centimeters
16 inches = 40.64 centimeters
3.14 * 15.24 * 15.24 * 40.64 = 29 638.2994

I'm almost scared to post that since I've been wrong so
many times in the past...

Don