This is refering to Pokemon Ruby Sapphire and Emerald only.
Collecting Berries
Each of the dozen of berries that you find across Hoenn can be Spicy, Dry, Sweet, Bitter or Sour. Since PokeBlocks are made from the berries, they'll have the same flavours as the berries that went to making the PokeBlock. Certain PokeBlock promotes the growth of a specfic Pokemon conditions, so you'll want to collect the right berries before you start making the PokeBlocks.
Using the Berry Blender
A Berry Blender makes a PokeBlock and at least two of users must operate a Berry Blender. Join game characters or recuit linked players to use the blender. First each user selects a berry. After the bender starts, each player must press A when pointer points at his/her name. Hitting A at the right time makes the blender accelerate, increasing the PokeBlocks quality level. When the blender stops, each user gets a PokeBlock.
Feeding PokeBlock to Your Pokemon
Dozens of diffrent PokeBlock can be made from blending certain berry combinations. Each PokeBlock will have a specific quality depending on how well it was blended.
Level
The higher a PokeBlocks quality level is, the more it will increase a Pokemon Conditions
Taste
A Pokemon will benefit most from eating a Pokeblock with a flavor it likes.
Feel
The more people who blend berries to create a PokeBlock, the greater the variety or berries, the lower (better) the smoothness of the feel will be. A Pokemon can eat PokeBlocks only until it has maximum, so if you want to feed many PokeBlocks, feet it only the smoothest.
Flavours and Natures
A Pokemon with a specific nature will enjoy PokeBlocks with specific flavours more and will benefit more from form others. It will dislike PokeBlock with certain flavours and wont get much out of eating them.
Taste
Promotes
Strong Nature Effect
Weak Nature Effect
Spicy
Cool
Adamant, Brave, Lonely, Naughty
Bold, Calm, Modest, Timid
Sour
Tough
Bold, Impish, Lax, Relaxed
Gentle, Hasty, Lonely, Mild
Dry
Beauty
Mild, Modest, Quite, Rash
Adament, Careful, Impish, Jolly
Bitter
Smart
Calm, Careful, Gentle, Sassy
Lax, Niave, Naughty, Rash
Sweet
Cute
Hasty, Jolly, Naive, Timid
Brave, Quite, Relaxed, Sassy
Chart of the Berries
Below is the list of all the Berries and the locations.
Berry
Discription
Location
Flavours
Aguav Berry
Eliminates Sleep Condition; confuses Pokemon if they dislike bitter flavours