Trim Brussels sprouts, removing any outer leaves that are too dark or are damaged. Trim dried-out base of sprouts and cut an "X" 1/4 to 1/2 inch deep in each.
Steam sprouts over rapidly boiling water just until tender, about 5 minutes, no longer than 7 minutes. Cool and cut into lengthwise quarters. Set aside.
While sprouts steam, cut bacon into thin strips. Cook in skillet over medium-low heat until crisp. Raise heat to high and add red wine vinegar. Cook until vinegar loses raw smell, about 3 minutes.
Reduce heat and add sprouts. Heat through, season to taste with salt and 1 to 2 tablespoons additional red wine vinegar if necessary. Add pine nuts, stir and serve.