In a large jar, combine the horseradish, honey, lemon juice, and 2 cups of vodka. Mix well until the honey completely dissolved. Pour in the rest of the vodka and close the jar with a tight lid.
Place the jar in a dark, cool place for a week and shake it once in a while. Then filter the vodka through a mesh thieve lined with a couple of layers of cheesecloth and pour into a glass bottle. Refrigerate before serving!