Grapes do not continue to ripen after harvest; they should be harvested at optimal maturity based on soluble solids content.A temperature of approximately 0°C is generally recommended for storage of grapes, at which they have a storage potential of several months. The storage life is dependent on maturity at harvest, rapid pre-cooling, an effective fumigation programme and low constant storage temperature. Keeping quality is dependent upon variety. The shelf-life of grapes reduces by approx. 40% at +4°C and by approx. 70% at +8°C. Stem respiration rate is approximately 15 times higher than berry respiration.
Sweet berries may not freeze until -3°C, but their stems (containing much less sugar) can freeze at -2°C, leading to wilting and berry drop. To avoid the risk of freezing damage, the recommended carriage temperature is preferably to be around the freezing point rather than well below. High relative humidity is necessary to minimise moisture loss (i.e. shrivelling of the berries) and maintain stems in good condition. Shrivelling and drying of the grapes may be prevented by packing the fruit in perforated polyethylene film inside the export cartons. The normal weight loss due to a reduction of moisture in the grapes is 2 - 3%.
In order to effectively avoid the loss of grapes due to improper temperature and humidity, the use of temperature and humidity recorders is a good choice. Fresh Tag 10TH is a temperature-humidity data logger with LCD screen. This series of data loggers are designed for recording and monitoring the temperature/humidity changes of sensitive products during their transportation and storage. They can be widely used in each stage of cold chains, such as refrigerated containers, refrigerated trucks, cooler bags, cooling cabinets, medical cabinets, freezers, and laboratories. This series of data loggers feature a large LCD screen for intuitive display. They can work for up to 120 days. Parameters can be configured on our free configuration software. After the trip is finished, connecting this logger to the computer, then PDF/CSV/PDF&CSV reports will be generated automatically without using the software.