Leeks are usually subject to cold water pre-cooling at 0-1ºC, vacuum pre-cooling or forced humid air.

Once they are in the storage room, leeks may last up to 3 months at temperatures between 0 and 1ºC. If the pieces are not in satisfactory condition or they have undergone frosts, the period shortens to one month.

In some countries they have extended the freezing period up to 5 months by using temperatures around -3ºC. The leeks are covered with plastic so as to avoid their drying. At the end of storage they need a very slow defrost at 0.5ºC for 48 hours. By using this system, if leeks are cleaned and vacuum packaged in bags, they shall have less losses.

Modified atmospheres are not used in leeks, since they are storage for several months. Nevertheless, the suitable conditions for this species are 1-6% of oxygen and 5-10% of carbon dioxide, at a temperature of 0ºC.

The leek transport must be carried out at temperatures around 0ºC. Distribution takes place at 5-10ºC. Leeks may have important losses of weight at these temperatures, so it is necessary to protect them to avoid dehydration. The levels of moisture must be high; direct light and piling must be avoid.

Among the different problems affecting leeks during storage are the diseases produced by fungi and bacteria. The most important is grey rot, caused by the fungus Botrytis porri. Some other diseases are caused by the fungi Phytophthora porri, that gives rise to mildew and Alternaria porri. Erwinia carotovora is a bacteria that affects leeks during their storage, producing wet rot.

Another very important problem during storage is dehydration. In order to avoid it, the levels of moisture must be near saturation and the produce must be protected with plastics.

The yellowing of the leaves and the loss of firmness is also a possible disorders in stored leeks.