The key responsibility of the ship is to ensure the carrying temperature (0°C) is maintained and that there is a legible record to confirm it
Table grapes are expensive and may be carried on pallets either in containers or in break bulk refrigerated vessels.
As grapes do not continue to ripen once they have been cut from the vine, they must be harvested in fully mature condition. Harvesting itself is a critical operation. Grapes can easily be physically damaged, and poor handling can result in a variety of physiological defects such as ‘wet shatter’ and ‘dry shatter’. The grape berries are attached to single stem called pedicles. The pedicles in turn are attached to larger stems known as laterals.
The term ‘wet shatter’ means that individual grapes have broken from the bunch either by a clean break between the berry and the pedicle, or as a result of the pedicle itself breaking along its length up to and including breaking directly from the lateral. When berries have become physically damaged, they are more susceptible to microbiological invasion.
When the grapes have been cut from the vine, they should be chilled as soon as possible. Even comparatively short periods of exposure at normal temperatures, say six hours at 20°C, can result in dehydration and browning of the stems which then often results in bunch ‘shattering’ during handling. It is therefore normal practice to cool grapes as soon as practicable after they have been harvested.
Vinifera fruit (destined for winemaking) is treated with sulphur dioxide at this stage to minimise the risk of deterioration of the fruit due to fungal growth. Later and particularly during storage, sulphur dioxide treatments are repeated at regular intervals.