One 750-ml bottle good-quality tequila, preferably gold
1 very ripe and juicy large pineapple, trimmed, peeled, quartered, cored, and cut into 2-inch chunks
1 vanilla bean, split lengthwise
2 Tbls. packed light brown sugar

In a medium container (a jar with a lid works well), combine the tequila, pineapple, vanilla bean, and sugar.  Cover and let stand at room temperature, stirring once a day, for 1 week before using. Refrigerate indefinitely for long-term storage.