Redberries can be obtained just outside falador, via lumbridge.
as to making the pie:
Chat with our AI personalities
i remember when i got one. you can buy it on grand exchange. if you still need help add 98ironman98 . =P
You can't make a black beery pie. There aren't any black berries. Non members can make Red-berry Pie Meat Pie Apple Pie Members can make Mud Pie Garden Pie Fish Pie Admiral Pie Wild Pie Summer Pie
Look for a berry that has dry circled in red on its tag use it in the berry blender.
Check a berries tag in your Bag find a berry that has a red circle around the word Dry use this berry in the berry blender to make a blue pokeblock or liteblue. Try using a Ganlon berry.
The red shard can be given to the guy next to the Pokemon center for a cheri berry,a pecha berry and a leppa berry.