Bellin’s progressing cavity pumps and lobe pumps find a wide range of applications in the wine (oenology) and beverages industry due to their versatility. They can be used for pumping wine and must during racking operations, for feeding filters during pumping over operations, for pumping crushed and/or destemmed grapes and fermented marc, or even for transferring whole grapes.
In order to prevent substances in the stalks, such as pectins, tannins, cellulose and resins, from giving the product undesirable or negative characteristics, destemming is carried out before the grapes are crushed. This process consists of separating the berries from the central axis that supports them.
After a further selection of the grapes, in which those that are broken or affected by mould are eliminated, the crushing steps takes place. At this stage, the following is achieved:
In particular, if the crushing is excessive, there is a risk of bitter substances being released.
The purpose of transfer is to remove solids deposited at the bottom of containers and to remove foul-smelling compounds responsible for the ‘reduced odour’, characterised by hints of sludge, scum, sulphur and even rotten eggs. These substances can volatilise and disappear with proper ventilation.
Racking is also carried out to transfer wine after clarification, to homogenise different batches of wine or to clean emptied containers.
After racking and pressing, a certain amount of solid matter, consisting of fragments of grape skins and pulp, remains in the must. At the end of fermentation, this coarse lees settle at the bottom of the containers together with dead yeast cells and must be removed by racking to prevent the formation of defective odours and flavours and possible future illnesses.