There are arguments out there and I feel like I have finally tasted the xbmt thoroughly enough to atleast advise otherwise. There is no reason a processed vanilla bean from your average grocer would need vodka. Making a tincture, the process in which you are adding alcohol to make a flavored alcoholic extraction, will give you as much vanilla flavor as adding it straight to the fermentation vessel. However, vodka will add its own flavor too. It may be subtle, so I recommend you add a spirit in which you are happy to taste in your beer. For instance if you don't like the flavor of vodka, I now don't recommend adding it to your beer, because you may detect it. I personally have only used a favorite whiskey and rum of mine. Which I never really had a problem with. Then I tasted a friend of mines replica of my recipe, but he used vodka (which I detest, and he used dark eyes which made me want to slap him but I digress) and I was unpleasantly surprised how much I could taste vodka. So it gave me the xbmt for a side by side test. We made 20 gallons side by side of my porter recipe split into 4 5 gal Big Mouth Bubblers. 1 Whistlepig, 1 Black Magic, 1 Absolut, 1 no tincture.
I found that the vanilla flavor and aroma was as strong in all of the tinctured brews. However the vanilla bean alone on the beer was even stronger. I can not say it was the preferred brew. However it was the one with the strongest vanilla character. All of the beers had the vanilla bean chopped and put into a bag tied to the outside of the fermenter. It was left on the beer for 4 days.
20 people tested blind and served all 4 brews but given 6 samples
17 people selected the brew to have the most vanilla flavor, but 13 found it to be overpowering the beer or being 1 noted (I was surprised)
10 people could tell there was a difference between the correct 4 brews
7 could detect different alcohol flavors correctly