The Lab

Post-Harvest Coffee Processing: Pulped-Natural and Honey

Pulped- natural and honey processing are different names for the same production style. The process was started and named pulped-natural in Brazil around the 1950s with the goal of increasing production by decreasing the time it took to dry the coffee. At the time, Brazilian coffee was overwhelmingly naturally processed. Costa Rica, where it is referred to as honey processing, has pioneered the use of this method for specialty coffee and producers have experimented greatly with different techniques for increased quality.

The initial processing steps are the same as the washed processing style. Cherry is picked and overripe or undeveloped cherries and debris are removed by floating in water. The coffee is sent to the depulper to have the flesh of the fruits removed. Drum and disc pulpers operate based on abrasion while more advanced pulpers will use pressure to force the seeds through screens and out of the cherry. Unripe cherry is harder and will require higher pressure to be pulped, so the miller will adjust the pressure to only pulp the desired quality of coffee.

The freshly pulped coffee may be laid out to dry directly after pulping. Similar to a natural process, the rate of drying will affect the final flavor. Drying the coffee quickly when humidity is low and temperature is high will result in lighter colored honey. Cool and humid drying conditions will lead to darker colored honey. Drying time can be manipulated through changing the depth of the drying bed and adjusting frequency of turning or raking. Deeper drying beds or less frequent turning will lead to slower drying periods and a subsequently darker colored honey.

Ultimately, the drying time is most heavily dependent on the environmental conditions when the coffee is laid out to dry. If the humidity is high and temperatures are low, darker honey will be produced and the opposite is true for hot, dry weather.

Demucilager patent image by popular brand Penagos

Some producers will pass the coffee through a demucilager which consists of metal rotors and water which remove varying degrees of mucilage. The coffee is loaded on the right side and is carried to a vertical chamber where the spinning augers lift the coffee to the rotors. The mucilage is removed mechanically by the rotors and water. The mucilage flows outside of the chamber through screens on the sides of the vertical chamber. Removing higher percentages of mucilage with greater water pressure and greater rotor speeds result in coffee that takes less time to dry. The lower amount of mucilage and will result in a faster drying time and lighter colored honey. Leaving higher percentages of mucilage on the seed will result in longer drying times and darker colored honey.

A darker colored honey will have more similar flavors to a naturally processed coffee because of the the extended period of dry fermentation. Microbes will breakdown the mucilage and produce aromatic compounds that influence the coffee’s flavor. Lighter honey will be more similar to a mechanically demucilaged coffee, but with some flavors associated with fermentation.

Costa Rica has found success in reinventing this processing style for specialty coffee. Other countries are following suit and honey processed coffees can now be found in across the Americas and in parts of Africa. Check with your trader at Royal NY for our full offering of honey processed coffees.

Patrick McKeown

Patrick began his coffee journey on Long Island at a small coffee bar and roasting at home. Since then he has been a barista, manager, and craft roaster in NYC.