Depends on why he is taking beans out of the roaster. The two (primary) times a player would be pulling beans from his roaster are BLEND and SELECT (research track).
BLEND is a random draw so the player does not look into the bag.
SELECT allows a player to look into the bag and remove a targeted bean. That is the power of this research track, you are increasing the odds for the random draw for the BLEND.
And to be complete:
BREW allows players to "SET ASIDE" beans when BLENDING. If you don't like the random bean you just drew, set it aside and continue drawing. Place the set-aside bean back in the roaster at the end of your turn.
If you research up to the second level of BREW, you may set aside twice.
If you research up to the second level of SELECT, you may remove a bean from your roaster and replace it with any bean in the fields of your choice.
BREW and SELECT are by far the best research abilities if you wish to constantly create top blends. Of course, INVEST and FLAVOR have their own charms. I'm not a big fan of the GROW tech, though I see new players always gravitate towards it, thinking having more beans in their roaster to always be a good thing. That is nearly always misguided.