Raisin Processing Plant & Machinery Solutions

Bunches are dipped in a hot alkaline emulsion that breaks the waxy bloom on the grape skin, and the fruit is then dried. Dipped grapes dry faster and more evenly than untreated fruit of the same size.

Dried fruit is separated from the stalks and the cap stems are pulled off each berry. Stalk and cap material is taken out here rather than being left to show up as a defect at the packing end.

Raisins are washed to remove field dust, sand and sugar bloom, and stones and tramp metal are separated out. The washed fruit is surface dried again before it moves on to grading.

Light stalk, cap and skin fragments are drawn off by air and the fruit is graded into size bands. Berries that have stuck together during drying are broken apart as they pass through.

Colour sorting takes out unripe green berries, sugared and darkened fruit, stones and foreign matter. Camera inspection follows to catch stalk and cap that came through the air stage.

A light food-grade oil is applied so the fruit stays loose in the pack instead of caking into a block. The raisins are then weighed and filled into pouches, cartons or bulk cases and coded.