How to buy fresh corn
The most important thing to remember when buying fresh corn on the cob is that it begins to convert sweet-tasting sugars into starches immediately after it is harvested. So, the ideal is to buy it, cook it and consume it the same day it is harvested or as close as possible. I have read that sweet corn has a sugar to starch ratio of 80:20 when harvested, but within 3 days that ratio will change to 20:80. That’s the difference between very sweet, tender corn and hard, floury corn.
When shopping, pick up each ear and look for ears that feel full and plumb in your hand. Look at the silk sticking out on top, it should be pale gold, slightly sticky, and the more the better.
Even though it’s messy at times and makes you messy when peeling, the more silk, the more kernels of corn. You also want the shells to be a nice green color, not brown. Although most shops don’t appreciate you doing this, try popping one of the cores with the thumbnail. If the juice of the grain is milky, the fresher the corn. And don’t buy corn that has been out in the sun all day. The sun and heat will speed up that conversion of sugar into starch.
Look at the bottom of the ear of corn where it has broken off the stalk. If it has already turned brown, it is most likely at least 2 days old.
If you won’t be cooking and eating your corn fresh that day, store it in the refrigerator with the husks on. Chilling it will help slow down the transformation of sugar into starch. You may also want to remove the long stem and larger outer leaves to prevent moisture loss. Will it last more than a day? Sure it will, but as the clock ticks down, so does the sugar/starch ratio.
Preparation of fresh corn: how to peel.
Start by peeling the shell from the top and removing it completely. Remove all fine hairs (silk) that run from top to bottom. If you are very picky about those hairs, use a vegetable brush or a damp cloth. Finish by breaking the stem at the bottom.
cooking fresh corn on the cob
There are many ways to cook fresh sweet corn. On top of your stove in a pot with water or steam, on your grill, in your microwave (bad choice), and I’ve even tried cooking a large batch of ears for a party in the dishwasher (but with bland results).
The most popular way to cook fresh sweet corn in our family is to boil it, although my wife and I use different techniques to boil it and both turn out very well. She likes to start with a large pot of cold water, add the corn, and bring to a boil. When the water boils rapidly, the corn is ready.
I learned as a kid to start by boiling the water first and then add the corn to it and let it cook for about 5 minutes. I don’t think it matters that much. Both ways always produce delicious corn. I have read in some cookbooks that a teaspoon of sugar is added to the pot of water to keep the corn tender. I don’t think it would hurt, but if you’re starting with fresh sweet corn, why bother?
cook don’t do
Do not add salt to the water. It only hardens the corn when it is cooked.
Do not cool hot corn by running it under cold water. It will make the corn soggy.
Don’t overcook or the kernels will harden and the corn will lose some of its sweet flavor.
finish it
I guess you can get “gourmet” and add all kinds of fancy seasonings, but I like my sweet corn plain with just butter, salt, and pepper. Sometimes simple is better.