The crunch of cornmeal is a nice counterpoint to the juicy burst of blueberries in these tender muffins. If organic wild blueberries or huckleberries are available fresh or frozen in your market, they are a wonderful stand-in for cultivated blueberries. These wild fruits are smaller and have thinner skins than their domestic kin. To keep the berries from sinking to the bottom of the muffins, toss them in a sieve with 1 Tbs. flour before adding them to the batter. If using frozen berries, add them without thawing or they will exude a lot of juice.