Rotho-Noxys: for more fragrant and aromatic white wines

Rotho-Noxys: delicate inert transfer of whole grape clusters

During recent years, hyper-reductive vinification in an inert atmosphere has become ever more common to produce high quality white wines, not just for proven international cultivars such as Sauvignon Blanc but also for numerous native Italian vine cultivars of great commercial importance.

The process requires coherence and control of all asspects of production. The most critical phase involves destemming and crushing, then transferring the crushed grapes to the inert press, as the speed of the enzyme reactions causes significant oxidation of the raw material right from the moment of loading into the press.

Ideally, the whole grapes should be loaded into the press with minimum contact with oxygen, but this is complex as it reduces production capacity and requires creation of an inert atmosphere with vacuum pumping and/or dry ice.

Ragazzini has carried out trials using its own integrated system involving the Rotho peristaltic pump fitted with the new Rotho-Noxys inert feeder. The aim was to find a solution for this critical phase in grape processing, able to guarantee maximum delicacy and maximum aromas, while also reducing exogenous antioxidants (sulphur dioxide in particular) to exploit the natural antioxidants in the grapes for more fragrant and pleasing white wines.

How the Rotho-Noxys works

  1. The product (whole grape clusters, not destemmed) is offloaded into the Noxys feeder by a belt, following inertization of the delivery tube and press.
  2. Thanks to the cylindrical configuration of the feeder, the oxygen is blocked by the accumulated mass of grapes which is accompanied to the bottom of the conical feeder by means of a broad spiral conical screw rotor from where it is pumped up by the Rotho.
  3. The slight crushing of the grapes creates several centimetres of must at the base of the cone and this forms a further barrier to contact with oxygen.
  4. Protective gas can, however, be introduced through nozzles located halfway up the feeder to totally eliminate oxygen.
  5. A level sensor in the wall of the feeder controls the inflow of grapes and starts/stops the system, operating the machine to achieve a suitable quantity of grapes to maintain the inert mass.
  6. The Rotho pumps up the product and conveys it delicately to the press.
  7. Both the Noxys feeder and the Rotho peristaltic pump are operated by independent inverters to obtain from 5 to 50 rpm, according to the type of grape clusters to be transferred and their integrity.
  8. The flow rates/hour vary from 6 to 9 m³/hour, again according to the type of grapes.