Harvesting sweetcorn at the correct time ensures that the kernels have developed and matured. Sweetcorn should be harvested when it reaches the milk stage, that is when the corn kernels release a milk-like juice once punctured. Monitor sweetcorn closely for ripeness after silk appears on the ears--the corn matures within 15 to 20 days on the stalk after that point. Once you harvest sweetcorn, store it properly to prevent a loss in sugar content.
Examine the silk on the ears of corn. Silk on mature ears appears brown and dry close to the tip.
Peel back the husks carefully to expose the top kernels. Ensure that the kernels have filled out at the tip of the ear; immature corn ears do not have full, juicy kernels that reach to the tip.
Puncture a large, plump kernel with the tip of your fingernail. Examine the juice that runs out of the kernel. The juice should appear milky white, not clear.
Grab the corn ear at the base when it is ripe. Twist the ear downward from the base to remove it from the stalk. Harvest sweetcorn in the morning.
Store sweetcorn in the refrigerator immediately after picking. The quality of the corn deteriorates rapidly once you harvest it. For best taste, store the corn at 00 degrees Celsius for no longer than 4 to 8 days before consuming it.
Always plant sweetcorn away from other types of corn; they can cross-pollinate, which affects the quality of the corn. Protect corn ears that are almost ready for harvest from bugs and birds by covering them with paper bags.
Avoid letting the corn sit at room temperature for longer than 12 hours after picking--it begins to lose its flavour.