Fresh Produce Cold Storage – Humidity Control vs Ambient Temperature

Food handling professionals at all levels tend to focus exclusively on ambient temperatures when it comes to cold storage of fresh produce.

Many a cold room door can be found in a hotel, restaurant, bakery, or conference venue pasted with a Temperature Chart showing daily readings as reflected on the temperature gauge.

Temperature gauges very rarely record the correct temperature as their probes are not correctly positioned inside a cold room which then gives rise to incorrect temperature readings.

Food auditors on the other hand tend to focus on core temperature to demonstrate whether a cold room facility keeps food safe and sound at the right temperature.

No argument that the correct ambient (and core) cold storage temperature of each type of fresh produce is critical to keeping food costs in check (and patrons safe) but another component of a cold room is equally if not more important, viz relative humidity.

Nowhere will you ever find a Humidity Reading Chart on a cold room door or even a food audit containing such information?


Simply goes back to basic food handling training at chef’s schools and colleges which only focus on cold storage temperature as the sole medium to ensure that fresh produce is stored safely.

Conversely, if fresh produce is not stored (even for a few hours) at the correct humidity level which is between 85% and 90% shelflife and qualitative condition ‘goes South’ and very quickly. Any humidity level lower than the foregoing recommended levels results in loss of moisture which leads to qualitative condition deterioration, loss of weight and colour, and food spoilage (over a period of time).


Fresh produce contains between 85% and 90% of water. To maintain prime condition from harvesting to packhouse to market to wholesaler to cold room, fresh produce should not be stored (repeat .. even for a few hours) at anything less than 85% to 90% humidity.

Humidity control is a science all of its own and when mastered, food costs are contained, profit margins increase and patrons come back for more (good quality food that is)!

Go to for further information and technologies to assist with humidity control, as well as ethylene and airborne bacteria extraction in cold storage.