It is recommendable to harvest sweet corn in the early morning. Immediately after the harvest, the corn should be cooled down, best to 0 degree, in order to slow down the metabolism in the grains, i. e. to slow down the transformation of sugar into starch. Normal sweet varieties can be stored at 5° for aprox. one week. However, their sugar content is then not much higher than that of freshly harvested field corn, which some consumer may get “directly”.
Extra sweet sugar corn varieties can be stored distinctly longer, and even after a longer marketing period their flavour remains sweeter.
For larger areas and when a suitable marketing partner is at hand, sweet corn can be marketed over a period of 10 days with the help of a vacuum or hydro cooling system. In this case, the cooling chain with aprox. 5 – 8° must be maintained by the corresponding retail shop. Directly sowed crops without row covers are usually harvested from mid of August until beginning of September (see chapter “Extension of the harvest period”).