Give the bottle a good shake every once in a while. Store in a dark, cool place for 2 months or longer.
Lasts for years. You can keep topping it off with vodka once in a while as you use it, just remember to give it a good shake.
You can also make vanilla sugar by putting a split vanilla bean into a jar of white, granulated sugar. Great way to infuse the sugar with vanilla flavor for baking.
Read more: http://www.simplyrecipes.com/recipes/how_to_make_vanilla_extract/#ixzz3U3Wgcgox