Pure vanilla extract is expensive, and if you are one of those people who are highly sensitive to even distilled alcohols (grain-based), then making your own vanilla extract is the best solution.
The highest quality of pure vanilla extract is produced by steeping vanilla beans in an alcohol and water solution for several months. The longer it steeps, the fuller the flavor and less bitter the aftertaste. After the percolation, the mixture is left to age (2 months to several years). For an even stronger, darker and richer product, some companies use oak barrels to mature the extract.
Lower quality pure vanilla extract is created by eliminating the long percolation and maturation process. However, to replace and imitate the complex and intense flavor compounds that are created during a long aging process, manufactures add a sweetener like corn syrup or sugar.
To create an extract you'll need to use 30g or 1 ounce of vanilla beans to 1 cup of alcohol. Any less than that and the strength of the extract created will be no more than an infused alcohol, and will be completely lacking in concentration and aroma.
Vodka or bourbon is traditionally used to make vanilla extract, however you could even use brandy or rum. Each would impart its own unique flavor to the blend. Grain free alcohols can be made from corn, potato, and sugar cane. See What Types of Alcohol are Gluten Free for more information.
I made both a vodka based vanilla extract and a bourbon based one, and found the bourbon version to be more flavorful (although the bourbon is naturally more richer in flavor and color on its own so that definitely gave the extract a bit of a boost). Having said that, after 6 months the flavor and aroma of either one was no where near that of the commercial pure vanilla extract.
I made a third batch with 2 Tbsp corn syrup added to see if it helped to infuse and deepen the extracts flavors quicker (as in the cheap commercial extracts), however I noticed no difference. It actually made the extract taste 'off', so I would not recommend any extract recipes that call for sugar of any kind.
Like a fine wine, where the vanilla beans are grown lend unique notes to their flavor. Madagascar, Mexico, Tahiti, West Indies, and Indonesian are just a few of the locations that grow vanilla beans each imparted with their own distinct aroma and flavor. High quality commercially produced extracts would be able to highlight these flavor variations, however for homemade versions, I would not recommend spending more money on exotically sourced vanilla beans.
Is It Worth It?
The key to (commercially made) vanillas strong flavor, bold aroma and deep color is its intensive percolation and aging process. These processes super concentrate the vanilla by a mild evaporation process, one that just can't be duplicated at home on the same level.
Vanilla beans bought at your local grocery store, will cost about $10 for 7 grams. That means it would cost about $40 (plus the cost of the alcohol) to make 1 cup of extract. Compared to $10 for 1/2 cup of commercially produced pure vanilla extract.
If you are able to consume small amounts of grain-based distilled extracts without reaction, I recommend buying pure vanilla extract. It's more economical and you'll get a better overall product. However if you can't consume even the smallest amounts of alcohol, then making your own is a great alternative for you.
P.S. Don't Throw Those Beans Out!
Beans that have been spent to make the extract can be dried and used to make vanilla infused sugar. Place dried beans in a container with granulated white sugar (or powdered sugar), seal and let sit for several weeks. Shake container every few days to break up any clumps that form, as well to redistribute the vanilla beans. Use wherever sugar is called for, and when you want a rich vanilla flavor.
- 10 oz glass bottle with stopper (or jar)
- 30g or 1 oz vanilla beans (approx. 10-15 beans)
- 1 cup grain or grain-free alcohol (Vodka, Bourbon, Rum or Brandy)
- Split the beans in half lengthwise, leaving a bit at the end still connect. Do not scrape out the beans, leave intact in the pods.
- Place split beans into bottle and fill with alcohol to cover. Seal bottle and label with the date it was made. Vigorously shake the jar and let sit in a cool dark place for at least 2 months, shaking again every few days or so for the first 2 months.
- Taste at the 6 month mark. The longer it infuses the better it will be (like a fine wine), so if you can wait until 12 months is up, all the better.
- If the bottle you used is dark, use the extract directly from the bottle (you can leave the beans in there indefinitely, as long as they are completely submerged). If you want to remove all the bits, strain it through a wetted coffee filter then pour into a dark bottle. The dark bottle will preserve its flavor, since light can begin to deteriorate the extract.
- Because of its high alcohol content, there is no shelf life for vanilla extract.