Optional: Some extract makers choose to split the vanilla bean lengthwise to accelerate the infusion process, while others avoid this step because they feel it makes the extract a bit more cloudy. I've tried both methods and think they both deliver excellent results, so choose whichever approach you prefer.
To cut the vanilla bean, use a sharp knife to create a slit lengthwise.
Place vanilla beans and liquor in a container, seal tightly and give it a good shake.
Store in a dark cabinet for at least 6 weeks, shaking occasionally.*
*When the extract has reached the depth of flavor that you prefer you can remove the vanilla beans to be used in a recipe. However, it is also fine to simply leave them in. Store in either a dark container or in a dark cabinet.