If you have cut the leafy green sections off of the pineapple, it becomes much easier to store. As we have already mentioned, the sugars enter the pineapple at the base where the stem was located. If your pineapple appears unripe, you could attempt to store it upside down. This will help any remaining sugars in the pineapple to spread out across the entire fruit and may help it taste slightly riper.
Grilling pineapple is a great way to encourage the natural sugars to caramelize. If it is a particularly unripe pineapple, you can sprinkle some brown sugar over the surface. This will enhance the flavor of unripe pineapple and will help to neutralize the bromelain contained within the fruit. Bromelain is an enzyme found naturally in pineapple which has a digestive effect. This enzyme is what causes pineapple to hurt your mouth as it actually breaks down your tongue and cheek cells.