Elsewhere, I asked which is the best, cheapest tasteless vodka for making home-made vanilla extract. I got a lot of responses, including several to use more higher proof grain alcohol, and bourbon or rum. I ended up using a cheap Polish vodka (Wodka) because it was cheap, came in a big bottle, and was there. I just don't buy the vodka snob thing. It's vodka. I only want something that tastes like nothing.
I then searched around for vanilla extract recipes and methods and was confused by the lack of specificity. Most of them didn't give specific ratios.
Then I got lucky, and found this website:
I highly recommend it if you are interested in making vanilla extract. He gives fairly exact proportions. His vanilla bean to alcohol ratio is quite a bit higher than most, and his reasons are good. Also, he says that it'll take 6 months for a proper extract to be created. This all sounds quite right to me. I never believed that you'll have a usable vanilla extract in a month, and that you can put two or three vanilla beans in 8 ounces of alcohol and have a real product.
Also, somewhere in the pages, which are chock-full of vanilla wisdom, someone claims that a higher proof doesn't necessarily make a better extract. I am not a chemist so I don't know for sure, but commercial vanilla extracts are 35% alcohol, and vodka is 40% alcohol. Perhaps using 90% alcohol (Everclear, Bak Spiritus) damages the delicate chemicals that are necessary to make a great vanilla.
In any case if you love vanilla, the Vanilla Review is your go-to site.
Disclaimer: I don't know the guy, and get no kickbacks.