Place Brussels sprouts with salt water to barely cover in a small Dutch oven. Bring to a boil; reduce heat, and simmer, uncovered, 20 minutes or until tender. Drain; place in a serving dish and keep warm.
Melt butter in a heavy saucepan over low heat; continue cooking 5 minutes or until butter is browned. Remove from heat and add vinegar, stirring well. Pour butter sauce over Brussels sprouts; toss gently.