Manufacture of potato crispsProcessing methods for crisp manufacture vary greatly but generally take the form of washing, peeling, trimming, sorting, slicing, rinsing, partial drying, frying, salting, flavouring, cooling and packaging.
Potatoes are first washed with drum or flotation washers being usually used. Stones, sand, dirt and any extraneous matter are removed. Potatoes are elevated into washers and peeled by abrasion. Peeled potatoes are trimmed to remove eyes, bruises and decaying portions.
Slicing is carried out using a series of blades mounted on a circular stationary plate and a rotating drum. Water is supplied to flush starch from the equipment. Sliced potatoes are washed, usually in drum washers, to remove surface starch and sugars.
Some manufacturers blanch crisps prior to frying using steam-jacketed water filled tanks. Typical process conditions are 65 - 95°C for one minute or more. After washing, surface moisture is removed by various methods including compressed air and blower fans, vibrating mesh belts and heated air.
Crisp frying may be batch or continuous; temperatures are in the range 160°C to 190°C and cooking times are typically between 1.5 and 3 minutes. When the crisps leave the fryer they are agitated to remove excess oil and discharged to a belt running underneath a salter.
Flavouring may be mixed with the salt or dusted/sprayed onto the crisps in rotating drums. Finally the crisps are cooled and packed