Bring the water, sugar and vinegar to a boil in a large pot.
Add the husked corn, submerging all the ears of corn in the water. Continue cooking on medium-high or high heat for 5 to 10 minutes. Once the water comes to a full boil, remove from the heat, cover the pot and let the corn sit in the hot water for 10 minutes or up to an hour.
If after 5 to 10 minutes of cooking the water hasn't come to a full boil but the water IS hot and steaming, it's still fine to remove from the heat, cover, and let sit for 10 minutes.