Cut off the top and bottom, remove the skin and eyes, and cut out the core. Slice into rings, chunks, or spears depending on your intended use. Use ripe pineapple (should smell sweet at the base and yield slightly to pressure).
Flash freeze: spread pineapple pieces in a single layer on a parchment-lined sheet pan. Freeze until solid (2 to 3 hours), then transfer to freezer bags and press out air.
No sugar, acid, or other treatment is necessary — pineapple's natural acidity protects its color and flavor during freezing.
For purée: blend fresh pineapple until smooth and freeze in ice cube trays or small containers for use in cocktails, smoothies, or marinades.
8 to 12 months.
For smoothies and blending: use directly from frozen. For grilling: use frozen or partially thawed — the slight extra moisture steams off on the grill. For eating: thaw partially in the refrigerator for a sorbet-like texture.