You can add this right to your homebrew or soak them in alcohol to make an extract and add that to your homebrew.
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12 Large Tahitian Vanilla Beans – Vacuum Sealed Grade A Vanilla Pods – Rich, Creamy Flavor & Aroma – Ingredients for Baking, Homemade Extract, Paste, Brewing, Coffee, Cooking – , 12-Pack – note that multiple variations of this product may be available, as such a different version may appear at this link