Knee-high by the 4th of July and one of the true treats of summertime, sweet corn is always sweetest when it's fresh and in season. There are new breeds of corn that are super sweet, but you'll still have options of yellow, white, or mixed to choose from - and each have their own distinctive characteristics. Corn should definitely be eaten as soon as possible after it's shucked and should really be eaten on the same day you buy it. Check for freshness by seeing if the husk is still green and tight around the cob and the silk golden. You can peel back the husk a bit and break one of the kernels with your thumbnail - ripe corn will exude a milky liquid while overripe corn will have either no or clear liquid.