Keeping the beans connected at the end of the stem, slice vanilla beans lengthwise.
Place in a resealable glass container, such as a mason jar.
Cover beans with liquor. Make sure that beans are fully submerged. If necessary, cut beans in half width-wise so that they are completely covered by alcohol.
Place in a cool, dark space for 2-3 months, being sure to shake the container at least 4 times a month.