title_body: Coffee ground sieves: Can they make a noticeable change in the flavor?
upvoted_answer: In all coffee-brewing methods, consistency is key. Different particle sizes of coffee will extract at different rates and controlling extraction rates and replicating them is part of making better and better cups of coffee.
  
  The Rafino seems to be tailored more towards the filter or french press brewer. In these brewing methods, fines, the smaller coffee particles produce the majority of the problem in extraction and off-flavours produced in the end cup. With filter brewing, it restricts water flow and can cause inconsistencies in the extraction. With french press, the fines can overextract due to the full immersion process and cause a lot more bitter flavours to be present.
  
  Filtering out inconsistent coffee grounds results in a much more evenly extracted coffee as the majority of grounds will extract more uniformly without any under or over extracting much more than the rest. This should give a much more balanced and bodied cup assuming other variables are as diligently controlled.
  
  Better grinders can minimise fines but an extra step can ensure particle size consistency. However I'm not sure about the extent of adverse effects of exposing ground coffee to air for so long would be to which I would suggest minimising grounds-sifting time.