In a large pot, add just enough water to cover the ears of corn. Bring the pot of water to a boil.
While the water is warming up, add white vinegar and sugar.
To the pot, using long tongs, carefully add each ear of corn. Gently add the corn in the pot of water so that hot water doesn't splash out.
While adding the ears of corn to the water, keep a close eye on the water level so that it doesn't boil over the pot.If the water level starts to get too close to the top of the pot, carefully use a large ladle to transfer some of the water out of the pot.
If needed, adjust the placement of the ears of corn so that each one of them is submerged in water. If more water is needed in the pot, carefully add just enough to cover each ear of corn.
Cover the pot with a lid and turn the heat down to low.Simmer the corn on low heat until the corn is just tender (about 8 to 10 minutes; may be less or more depending on the size of the ears of corn).Be careful not to overcook the corn or it will be tough.
After the corn is done cooking, using tongs, transfer each ear of corn from the pot onto a large plate in a single layer. Let the ears of corn cool on the plate until they are cool enough to handle (about 8 to 10 minutes).