For what it's worth, I've used vodka tinctures for vanilla flavor. 8oz of vodka and two split vanilla beans. My results were a mellow vanilla background flavor and no vodka. I have a well stocked bar and can tell you that not all vodka is the same. Some are very neutral-- my taste buds are not so refined to taste 7.5 oz (after straining) of neutral vodka flavor in 600+ oz of brew. See what works for you--