Wine Production : Vine to Bottle - Vinum Vine

74
WINE PRODUCTION
12.1.2 Batch press
This category can be divided into three basic types: the horizontal plate
press; the horizontal pneumatic press; and the vertical basket press.
12.1.3 Horizontal plate press
This type is very often referred to as a ‘Vaslin press’, being the name
of the original company of manufacture, just as we often call a vacuum
cleaner a Hoover. (NB: The present day company Vaslin–Bucher
makes a number of different types of press.) A horizontal press
consists of a perforated cylinder containing a system of plates, hoops
and chains. Grapes are loaded into the press through a hatch which
is then closed, and the press rotates, tumbling the grapes. At this
stage, high quality free run juice is extracted. Then two metal plates
move from each end along a screw towards the centre of the press,
squeezing the grapes between them and releasing good quality juice.
The cylinder then rotates in the opposite direction, and the plates are
returned to the ends of the press. For the next pressing, the press first
rotates, and the ‘cake’ of pressed grapes is broken up. The plates
return to the centre forcing more juice, but of a lower quality, from
the grapes. The press may operate three or more times in this way.
In each grape berry, the best quality juice is in the area called
Zone 2 – this is neither close to the skin, nor the pip, and it is this
juice that is released in the first pressing. Plate presses are not the
most expensive, and are particularly popular with smaller properties
making red wines. An illustration of a horizontal plate press is
shown as Fig. 12.1.
12.1.4 Horizontal pneumatic press
This type of press is sometimes referred to as a Willmes or Bucher
press, again after the names of the original companies of manufacture.
Pressing in a pneumatic press is a relatively gentle, low pressure,
operation. An illustration of a pneumatic press is shown as Fig. 12.2.
The press rotates, and a central rubber bag, bladder or sheet is
inflated by means of compressed air. The grapes are pressed against
the entire slotted cylinder – a much larger surface area than in the
plate press. Again, several operations will take place to extract all