I go thru a lot of vanilla extract in this house. I always double (or triple, or quadruple...) any amount called for in a recipe. And I only use pure vanilla extract because the imitation stuff is flavored from wood by-products and chemicals. Heinous! Pure vanilla extract will last forever and it only has two ingredients.
Real vanilla extract can be really expensive though. I've seen it go for as much as $20 for 8 ounces. Instead of becoming a slave to the makers of rich, pure vanilla extract who charge the price of a small car for this liquid gold, I make my own. It's easier than you think, as long as you have enough patience to wait. Like 2 months.
I bought a half-pound of extraction grade vanilla beans online at Amadeus Vanilla Beans. Let me tell you, half a pound of vanilla beans is like a small football sized amount. Some people say the beans must be soft and fresh but I prefer the drier ones. They are not pretty, and they are a bit hard, but once they are in the liqueur of your choice, they soften up. Plus, with a lower moisture content, you get more beans in your half-pound than the same weight of pretty, plump ones.
So what booze to use? I started with vodka, which is the traditional extract liquid. It's flavorless so all you taste is the rich vanilla. I also pulled out the bottle of bourbon we always have in the front of the liqueur cabinet. And behind those bottles was a bottle of rum left over from Thanksgiving.
Why some people use bad liqueur to make extract, I have no idea. I find the foul, harsh, gasoline flavor in such bad liqueur doesn't go away simply by adding vanilla beans. That would be like putting whipped cream and a cherry on a steaming pile of puke. I used Tito's vodka, Maker's Mark bourbon, and Cruzan aged rum.
This photo is vodka extract after 3-1/2 weeks. I bought this bottle for less than $3 at Walmart. It took the two small (pint) jars to fill it.
You'll need glass jars of some sort to store your extract in. I used several sizes of empty mason jars.
This shows what the jars look like only moments after filling. The small pint jar in the front has the rum, which is a barely different color than the vodka. The bourbon one is obvious. After only a day or two you'll start to see the color change.
The large jar and two of the smaller ones have vodka. Here's a closer look.
Homemade Vanilla Extract
8 oz. liqueur (vodka, rum, bourbon, or brandy; at least 35% by volume)
5 or more vanilla beans (I use a lot, but you'll need at least 5)
glass jars with lids
Take each vanilla bean and with a sharp knife, cut down the bean lengthwise to open and expose the tiny vanilla bean seeds. Place beans in glass jars and add alcohol. Put the lids on. Store in a cool, dark place for 2 months to extract, shaking daily for a week, then whenever you think about it after that.
As you use your extract, the vanilla beans may become exposed. Now you have two choices. You can either top off with more booze, or yank out the beans and stuff them in a jar of sugar to make yummy vanilla sugar. If you leave them exposed (as I did once) they'll get slimy and yucky and ruin your extract.