Grapes harvested often have stems, which contain soluble substances such as malic acid, citric acid, and bitter resin. If not removed, it will affect the quality and flavor of grape juice, and if used in winemaking, it will affect the quality of the wine. Therefore, mechanical methods must be used to separate the stems from the grapes before juicing. Usually, grape crushing and separation machines are used for crushing and separation work.

The grape crushing and removing machine consists of a hopper, two toothed grinding rollers, a cylindrical screen, a blade crusher, a screw conveyor, fruit stems ****** and juice pulp *******, etc. The grape fruits with stems fall from the hopper and are slightly crushed between two toothed rollers rotating in opposite directions, and then enter the cylindrical screen for separation. The main shaft of the separation device is equipped with blades arranged in a spiral pattern, surrounded by cylindrical screening plates.

Grapes are further broken and separated from the stem under the action of leaves. Juice, fruit pulp, and fruit peel are discharged from the sieve holes of the cylindrical sieve and fall into the screw conveyor located below the cylindrical sieve, and are discharged from the left side of the juice pulp *****. And the rod-shaped fruit stem becomes the sieve material, which is unloaded from the stem ******. During operation, the gap between the two toothed rollers, the installation angle of the blades, the speed of the main shaft, and the size of the sieve holes should be adjusted according to the size, maturity, and stem condition of the grape grains, in order to avoid excessive crushing of the fruit, which may cause the components in the stem to mix with the juice and affect the quality of the product.