I was going to ask that, and how long you let it diffuse before using. A fifth is 25.36 ounces, more than three times the volume I’ve been using, so I’d guess you have to wait quite a while, unless you’re using a lot more beans than I did.
All right, I’ll confess, we didn’t do a blind taste test. But the good thing is that, in the long run, making your own is even cheaper than buying the fake stuff.
I wonder if using grain alcohol and diluting it down would produce better and faster results, or if it might extract some undesired flavors. I know my father (and I when I briefly got into the hobby) would use vanilla in some of our homemade herbal liqueurs, and we’d extract it in 192 proof Spirytus grain alcohol. Then we’d bring it down to around 80-100 proof with a sugar and water solution, but the sugar is only there for the liqueur. You can use straight water, of course.
That will work. I’ve done it with Everclear.
Many people stuff the bottle with vanilla beans, but I just used a 2-pack, slitted the long way and steeped until I wish to use it.