Ripe Coffee Cherries Ready For Harvest

Harvesting, Milling and Packing Coffee – Part 2 of “All About Coffee”

We started this feature with The Coffee Tree – Part 1 of “All About Coffee” and now here is part two of All About Coffee covering the coffee cherry as it get harvested, milled, dried and ready for shipping to the US.

Ripe Coffee Cherries Ready For Harvest

Coffee harvesting: Coffee is usually harvested once per year (possibly twice depending on the region source) during the dry season when its cherries ripen to a bright red, glossy, and firm state.

Harvesting  Coffee Cherries

 

There are two methods of coffee picking: mechanical harvesting by machine and selective picking by hand.  The best method is selectively by hand as it decreases the chances of a cherry being picked prematurely. Unripe green cherries result in displeasing bitter flavors with a sharp odor whereas ripe cherries yield more fragrant, smooth, and mellow notes as well as a lower acidity level.

Coffee Harvest Picking and Sorting

Although this process is preferred, it is labor-intensive since pickers rotate among trees every 8 to 10 days during harvesting season.

Picked Coffee Cherries Ready for Milling

Coffee Milling: After harvesting, the coffee cherries must then be set to dry.  The oldest and “natural” method of this process is the Dry Mill where the coffee cherries are cleaned and sorted before its exposure to the sun. Depending on weather conditions, those cherries can be laid out on patios for up to four weeks to dry while being raked regularly to prevent mildew and to ensure even drying.

Coffee Beans Drying

Once ready, the outer coffee layers (pulp and parchment) are removed from the coffee seeds, or beans.  After processing, the beans are further inspected and cleaned, and polished to remove any layers left on the beans.  This limits the chance of any byproduct (“chaff”) from roasting the coffee beans.

Coffee Harvest Wet Milling and Fermenting

A newer method was introduced, the Wet Mill or “washed coffee”, by using specific mechanical equipment and a substantial amount of water. Within hours after harvesting, the coffee cherries undergo Pulping – removal of the fruit covering; Fermentation – in its own mucilaginous layer with the help of fungi, bacteria, and yeast; Washing – to present a clean, rough, and whitish appearance without any residue, and then Drying – within a humidity level between 10-12%.  The Wet Mill process has become the preferred method over the Dry Mill simply because it yields the better quality of the coffee beans.

Coffee Bean Sorting

Coffee Selection and Storage: Once the drying phase is complete, the coffee beans turn into a blue/green color where its almond shape is revealed.  The “green coffee” is then sorted by size and density, color and looks, and into grades (i.e. the top three grades in Colombia are Supremo, Excelso, and Milds).

Coffee Beans Packing and Aging

Next, the coffee is packed accordingly into burlap bags weighing up to 70 kilograms per bag.  For optimal quality, the packed green coffee must be stored in a dry, clean, well-ventilated space.  In fact, aging the green coffee beans for up to a year before roasting has yielded the best flavors and aromas.

 

2 comments

  1. Jeremy Thompson 18 December, 2017 at 21:23 Reply

    It’s interesting to learn that coffee cherries are milled in the traditional way by cleaning them and exposing them to the sun for up to four weeks and consistently raked for equal exposure. Personally, I that is pretty much exhausting to do and probably why more and more industries are adapting to the mechanical milling that my son told me about the other day. It’s a little alarming to grow out of tradition, but I think it’s worth it as long as there is quality with its efficiency. Thanks!

    • Laura Rogers 23 January, 2018 at 13:31 Reply

      Hey Jeremy,
      There are a couple cool ways to dry coffee, while dry processing them dates back further, it does take a long time to ensure the coffee beans are dry enough for the next stage. We use a water process in our mills which is efficient, time sensitive and our process ensures we use very little water. Coffee is definitely fun to learn about!
      Thanks for your comment and have a great day.

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