I just received a free box of fresh pineapples and wanted to preserve them for later use. I love fresh pineapple, but after eating it all day my lips were starting to feel like I'd been kissing a porcupine. I have no practical experience with that pastime, unless you count the days that Tom has just trimmed his mustache :)
So got my trusty pressure canner out and washed up some quart jars, pulled canning lids and rings out and got started cutting up the pineapple. The instructions in my pressure canning book called for cooking the pineapple in a heavy syrup before filling your jars. I didn't add any sugar to the water and figured that if it really needs it, we can add a little honey or sugar when we eat the final product. Boil the pineapple in water, or heavy syrup, for 10 minutes and then pack it into clean canning jars, filling to 1/4" from the top. Wipe the tops of the jars with a clean, damp cloth, put your lids and rings on and place them in the pressure canner. Mine takes 2 quarts of water (with a tablespoon of vinegar to reduce hard water deposits) in the bottom and I can fit 7 quarts or 9 pints in one batch. Put the lid on the canner and turn the heat on. When steam starts escaping from the pressure valve, wait 10 minutes before putting the pressure gauge on top. Use the 5 pound pressure setting and wait until the lid seals and the gauge starts to jiggle. Keep at 5 pounds of pressure for 15 minutes, then turn heat off and allow the pressure to reduce naturally.
Be sure to follow the instructions for your pressure canner for best results. You can also use a hot water bath method, but I like using the pressure canner because I don't have to do quite as much work or heat the water to boiling ahead of time.