Assemble ingredients. Put ice in cocktail shaker.
Add Peychaud's Bitters (2 dash) and Fresh Blueberries (10) to a low ball glass.
Juice Lemon (1/2) and add to cocktail shaker.
Add Rum (1.5 fluid ounce) to cocktail shaker and stir with bar spoon.
Pour chilled rum and lemon into low ball glass. Add a few pieces of ice or strain completely -- your choice!
Top with ginger Ginger Beer (to taste), garnish with lemon wedge, and serve!