Sterilize a 2 litre wide-necked bottle. Remove the skin and all brown scales from the pineapple. Cut in half, remove and discard the central core. Chop pineapple flesh into pieces small enough to fit in the bottle neck. Once the bottle is completely cold from sterilizing, place in pineapple pieces.
Place brown sugar and tequila in a jug and mix until the sugar has dissolved. Pour into the bottle and place in the vanilla bean. Seal the bottle. Gently swirl bottle a few times each day for 1 week before drinking.