Concord and Niagara grapes have what is called a slip skin, and offer a unique eating experience totally independent of Europen-type grocery store grapes. The usual way of eating this type of grape is to hold a single berry with your fingers, squeeze the berry firmly into your mouth to get all the juice, and swallow the pulp whole, including the seeds, and then throw away the skin. The pulp and skins are more acidic if chewed, however the skins are rich in antioxidants and very nutritious if eaten. Alternatively, chew the whole grape, including the skin, and sieve out the seeds with the teeth and tongue. Or for every last bit of nutrition and fiber, crunch the seeds to get the grape seed oils. Whatever your favorite method, be sure to introduce a friend to this eating experience!