To make your own, homemade, pure vanilla extract, you first need to find a bottle that’s tall enough to accommodate the vanilla beans. It should be at least 8 inches (20 cm) tall. The ones pictured here are a little over 9 inches (23 cm) tall. It also should also have a wide opening so that you can fish out the vanilla beans that have been in there for a while.
Depending how wide the bottle is, put in about 20 vanilla beans and then fill the bottle with vodka. Allow the vanilla beans steep in the vodka for several weeks, until the liquid has a deep, amber color (like the bottle on the left) and vanilla aroma.
Top off the vanilla extract with vodka as you use it. Refresh periodically with new vanilla beans. Soaked vanilla beans can be dried and used to make vanilla sugar (just bury the dried vanilla bean in a small sealed container of sugar). You can also cut off one end of the soaked bean and squeeze out the vanilla paste to use instead of vanilla extract in recipes such as Vanilla Bean Cheesecake Cupcakes with Berries & Cream.
Because vanilla beans are expensive, you may want to start by making a small batch: put two vanilla beans into a small bottle, fill with vodka and allow to steep as above.