Storage Conditions

A well-designed storage facility enables the user to dry, cool, and store the product by creating the optimal temperature, humidity and CO₂ levels. By creating the optimal storage conditions disease and sprouting is prevented, and the product quality is maintained.

Temperature and humidity
In general, the following conditions are used for long-term storage.

Product Storage Temperature ˚C Storage Humidity Relative % Max CO₂ – Levels Parts Per Million (PPM)
Carrots 0-1 C 95-98% < 10.000 ppm
Onions 1-2 C 65-75% < 10.000 ppm
Cabbage 0-1 C 90-95% < 10.000 ppm
Red beets 3-4 C 85-90% < 10.000 ppm
Consumption potatoes 4-6 C 92% 7.000 ppm
French fries 5-8 C 92% 3.000 ppm
Chips potatoes 7-12 C 92% 2.750 ppm
Seed potatoes 2-4 C 85% 5.000 ppm


In storing potatoes, the period of storage consists of five specific steps which have to be taken

  1. Drying
  2. Wound healing
  3. Cooling
  4. Conditioning
  5. Warming to desired processing temperature

Additional important information

  1. It is very important that the product that comes into the storage is healthy. Bad product cannot be stored
  2. Preventing damages during harvest and transport will repay itself during storage
  3. Take care that product is not coming in either too hot or too cold
  4. For a healthy batch of potatoes the product is to be stored with some soil which is evenly spread through the batch. This is a moisture buffer


The storage period of onions consist of 4 steps:

  1. Drying
  2. Cooling
  3. Storage
  4. Warming to desired processing temperature without condensation

For long term storage of onions it is needed to dry the onions in a correct way, so that the neck is completely closed. The way of drying depends on climate and harvest conditions.


Healthy carrots must be cooled upon arrival in the storage to a wound healing temperature of approximately 10 to 12 °C. after a period of three days the product can be gradually cooled to a desired temperature of approximately 0 – 1 °C. Unhealthy product must be cooled as quickly as possible to the desires storage temperature to prevent mold and bacteria diseases. In the storage facility it is vital to have proper air circulation to prevent differences in product temperature. During storage respiration of the product continues which emits CO₂. With a CO₂ percentage of over 3% visible damage may occur.