I learned this method from a woman named Sandy Gluck, a wonderful recipe tester who tested recipes for my cookbook, Bread Toast Crumbs. Vinegar: Many people wonder why there is a need for vinegar. Vinegar helps the egg white set, preventing them from spreading everywhere. Some people believe this not to be necessary, especially if the eggs are fresh. This may be true. I have tried poaching without the vinegar, and I do find the egg whites spread more, so I always use the vinegar. I never find it makes the eggs taste too vinegary.