Cut the sweet corn kernels from the cob with a sharp knife. Mix together all the ingredients except the oil. Cover and refrigerate for at least half a day.
Heat a spoonful of oil in a frying pan and drop in tablespoons of the crab mixture. Fry in batches briskly until brown and flip and cook the other side. Drain the fritters on paper towels and keep warm until all are cooked. Serve as soon as possible.