Peel several pineapples. Cut into small pieces; put into large kettle. Cover with water just even with the fruit. Boil gently for twenty minutes. Cool. Put one cup of the cooled juice into the blender and add part of the fruit. Blend well and keep repeating until all is blended. Of if you don't have a blender, grind the chopped fruit. Strain the juice and chill well. Thin with drinking water, if desired. A small amount of sugar may be added, if desired. Can be frozen or canned.