That depends on what type of corn it is, when during the day it was harvested, how long ago it was harvested, how it was treated after being cut, when you bought it, and how you treated it since you bought it. Just give us all those answers and we’ll be glad to tell you whether of not it’s still good. And by good, we’re talking flavor. Corn looses it sweetness and flavor long before it spoils.
If it is a traditional variety of sweet corn, half of the sugar can convert to starch within two days, and you and your dining companions will think, “yish, what’s so great about sweet corn?”
If it is a supersweet or sugar enhanced variety, it can still taste sweet after 10 days. If it was cut in the cool of the morning, cooled with water, and/or refrigerated, if it did not spend days in transit and/or at a grocery store, it may last some days longer than corn that was not babied.
Our repetitive suggestion is, don’t pick up corn on your weekly shopping trip and bury it in the refrigerator. Buy corn because you want to eat it today (or tomorrow), and then do it.
Generally when we get a question such as yours, we find that the questioner has had the corn in the refrigerator for several days longer than he or she intended, and wonders if it will still have flavor. We, of course, have no way of knowing because of all the variables already mentioned. Your best option is to get the water boiling and cook an ear or two. If you like it, cook the rest.
If you must store corn, there is a somewhat complicated process that slows down the respiration of the corn and will allow you to keep it for as long as two weeks. Mix up a solution of several gallons of ice water with two drops of chlorine bleach and one drop of lemon juice for each gallon of water (we’re not kidding – those trace amounts change the chemistry of the water, which kills microbes). Shuck and desilk the corn and drop it in the water for at least 15 minutes. Remove the corn, drain them, and pack them in food storage bags that are thin enough to allow oxygen to permeate (between .8 mils and 1.75 mils thick). Store the corn in the coldest part of the refrigerator, and – depending on how fresh the corn is when you perform this process – it can last as long as two weeks.