Make a copycat version of Kahlua by combining water, vanilla beans, vodka, sugar and instant coffee granules together. The process takes several weeks to complete, as the mixture needs time to infuse the vodka. The infused vodka is strained and transferred into six 12.5-ounce bottles.
To make homemade Kahlua, combine 8 cups of sugar, 4 cups of water and 1 1/2 cups instant coffee granules in a large pot over medium heat. Stir until the sugar and coffee granules have dissolved. Remove from the heat, and cool to room temperature.
Add 4 1/2 cups 100-proof vodka, and stir to combine the ingredients. Cut 2 vanilla beans into thirds and place inside 6 12/5 ounce glass bottles. Pour the vodka mixture into each bottle. Cap the bottles and store in a dark location for two to three weeks.
Strain each bottle individually to remove the vanilla bean remnants. Rebottle and recap the Kahlua to preserve freshness. Add a label and store in the cupboard.
Many variations exist for homemade Kahlua. For example, substitute equal parts of rum for the vodka to create a heavier-bodied drink designed to serve over ice. Swap instant coffee granules for freshly brewed coffee for a more intense drink. The flavor of the Kahlua varies depending on the coffee used.