Leave the stems on the mint. Gently crush the leaves in your hand and place them in a quart jar. Pour vodka over the mint and steep for 5 days. At the end of 5 days, strain the mint from the vodka and store in the refrigerator. If you reuse the the quart jar, rinse it before putting the vodka back into it. This will last 3-4 weeks in the the refrigerator.