Within the fresh produce industry shelf life is one of the keenest drivers of quality. It is important therefore to remove field heat as quickly as possible. This specialised vacuum cooling technique is widely used for cooling fresh produce from harvest temperature say up to 30o C, to storage temperature 2o C in twenty minutes. Traditional cooling methods would normally take many hours.

The vacuum cooling process has such a beneficial effect on product shelf life that most supermarkets already stipulate it as a prerequisite when supplying leafy type produce. The cooling process requires the pallets of produce to be loaded into a vacuum chamber. The chamber is closed and a vacuum is created using large vacuum pumps. The vacuum created lowers the boiling point of the water contained in the product. The water boils in the product at 2o C the action of boiling requires energy, which is provided by the higher temperature of the product, so the energy removal cools the product; this takes place uniformly throughout the product. Valley Engineering vacuum coolers are fully computer controlled and as such have the benefit of being extremely flexible. Valley Engineering have recently introduced a 'Computerised Hydrovac' system that allows constant replenishment of moisture that may be removed during the cooling cycle. This in turn has not only further improved shelf life but opened up vacuum cooling to the vegetable and other fresh produce industries.
Valley Engineering are driven by innovation and as such are clear leaders in the field of vacuum cooling not only in the UK but throughout Europe.