Instructions
Obtain a Pokeblock Case. You cannon make Pokeblock candies until you have one of these cases in which to store them. In Pokemon "Ruby" and "Saphire," you can get a Pokeblock Case by speaking to a small girl in the Contest Hall at Slateport City. In "Emerald," you can get a case by speaking to a small girl in the Contest Hall at Lilycove City
Find the right berry. Only certain berries will make purple Pokeblocks. In addition, some berries will only make Purple Pokeblocks when blended in certain cities. If you are using the blender in Verdanturf or Fallabor, you will need a Razz, Pinap, Pomeg, Tomato or Spelon berry. If you are using the blender in Slateport, you will need a Leppa, Lum, Figy, Razz, Wepear, Tomato or Spelon berry. If you are using the blender in Lilycove, you will need a Lepa, Persim, Figy, Razz, Nanab, Pomeg, Qualot, Tomato or Spelon berry.
Take the berry to the Contest Hall in the appopriate city and approach the Berry Blender. Select a berry to put in the blender. You will be joined by non-player characters who also will add berries to the blender. Once the blender starts to spin, you will have to keep it going by pressing the "A" button every time the spinning red dial lines up with the marker by your name. The more accurate your timing, the faster the blender will go, creating a stronger Pokeblock candy.