How Coffee Processing Affects Flavor

May 10, 2023
Farmer turning coffee during processing

Today I would like to tell you a little about coffee preparation at origin.  There are two major (and some minor) processes to get the fresh coffee cherry to the exportable ‘green’ stage.  One is called Washed and the other is called Natural or Dry process.  There are also, currently, about a dozen other new preparations done with or without oxygen, with different microbes, different temperatures, and more.  Mostly these processes are confined to very small quantities of from just ten to a couple of hundred pounds.  We won’t be concerned with these for the moment (if ever). 

The Washed process starts in a wet mill where water is used to separate the ripe from the immature cherries (the ripe ones sink).   Then the cherries go to the depulper where the skin and fruit are removed and then moved (by the water) to large fermentation tanks.  It is there that the sticky coating called mucilage is eaten away by microbial activity over the course of 12 to 36 hours depending on the weather conditions.  Water is then used to move the coffee from the fermentation tanks through sluices, sorting the coffee by density along the way, out to either patios where it is sun dried or to mechanical dryers to finish the process.  The result is called parchment coffee which then goes to a dry mill for final milling (to remove parchment) and sorting, weighing and bagging for export. 

Natural or Dry process uses no water (but I bet you already had guessed that).  The coffee cherries are picked and then put on beds, either raised above or on the ground (above the ground being preferable), to dry.  They are turned multiple times to prevent mold, and they are covered up at night to keep moisture out.  It usually takes two to three weeks for the coffee to be thoroughly dried this way.  It is then that the now dried skin, fruit, and parchment are removed.  The coffee is then sent to the dry mill for final processing as the Washed coffee is.  The advantages of the Washed process are a brighter acidity, a cleaner/sweeter and more consistent cup.  Most better coffees are processed using the Washed method.  Most lower quality coffees are processed using the Natural process. But (and this is a very big but) some of the very best coffees in the world are Natural process coffees.  When a high quality coffee is properly cared for during the long Dry process, the result is something amazing.  The fruit flavors are huge!  Juicy strawberry, tart blueberry, sweet pineapple, and on and on.  The first Natural I tasted was an Ethiopia Harrar.  It was processed and exported by a giant of the coffee industry, Mohamed Abdullahi Ogsadey.  A legend in Ethiopia.  (More about him another time).  The fruit flavors were so intense that one of my customers, upon returning to my shop after trying the Harrar, said that if flavors were colors the Harrar would be purple!  I agree.



  1. Sam Merrell

    I had the same experience with Harrar–but from the Third Ave and Grand Central stores. Your recent (early ’24) Guji batch was quite something too!

  2. Steven Silver

    Funny you should mention your Ethiopian Harrar. Many years ago I bought a bag of that at your store on 71st St. and it literally changed my persirctive on coffee. The way you describe it in the blog above is exactly the way I remember it.

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