Begin by sterilizing all bottles and caps. Bring a large pot of water to a boil, carefully place bottles and caps in and boil for 30 minutes. Remove and let dry.
Cut each vanilla bean in half so they'll fit into the small containers. Next, slice the beans in half lengthwise, leaving an inch connected at the end.
For the small containers that I use (link below), I add 3 or 4 vanilla bean HALVES in each bottle. Place funnel in and top with plain vodka, ensuring that the beans are completely submerged. Screw on tops and give each bottle a quick shake.
Store in a cool, not-too-hot location, shaking from time to time. The extract is useable after one month, but I let it sit a full two months before gifting it to friends.
When the bottle is only ½ to ⅓ full, top it off with more vodka, give it a little shake, then rest easy knowing it'll be ready to go the next time you need it. Never buy vanilla extract again!