Colombia, part 2 - The Mill

Ever carried 70kg on your back? Us neither. That’s the weight of a bag of Colombian green coffee, ready for shipment to roasters like us to turn into the amazing cup you’re drinking right now.

Enter the mill. You hopefully read the first chapter of our Colombian insights ‘The Farm’ where we shared some of the learnings from our trip to a Colombian coffee farm, from the seedlings to depulping and then drying the coffee cherry. Many forget that this is just the beginning to get the coffee ready for export, and there is another important step for every coffee grower – and so we enter the mill.

Will and I were taken to a local mill just outside of Medellin and were in awe from the moment we walked in the door. Thousands of bags of coffee lined the left wall ready to be milled, and on the right, thousands of bags ready to be exported to roasters like us all around the globe.

green bean density sorting

The process began with the unloading of a truck, filled with bags of dried coffee stamped with many hours of love and sweat of the coffee farmer. The bags were then put through a standard milling process including the milling itself – a process that removes the pergamino (parchment layer) from the bean, followed by sorting, sorting and sorting. We’re not even kidding. The beans at this particular mill were sorted by size using a screening method, pretty simple right?

Then they were sorted by density, now we’re getting a little more complex with angled beds, pressurised air and some serious knowledge that places the paddles exactly in the right position. The result from this step is that many defective beans are extracted, and the various qualities are sorted allowing premium beans (the type we use!) to be grouped accordingly.

Given the vast amount of coffee that don't make the cut, thankfully these beans don’t go to waste. There is a huge global market for commodity coffee and this typically ends up in places like instant coffee or other sources that don’t demand the quality we all know and love. Based on the amount of these beans in the bag, the farmer still receives income, though far less than that of the premium beans he/she can harvest.

Next up the most mind-blowing step of all, the final step to weed out any defects, sorting by colour.

A picture says a thousand words so take a look, I don’t feel I could do it justice! Our jaws dropped when we saw this machine and didn’t close until we left the plant. The speed… the accuracy… just wow.

green bean sorting

This mill was an example of a highly sophisticated mill, and would vary greatly from the hand-sorting we would typically see in countries such as Ethiopia, Kenya or the Philippines. At the heart however the process is the same, in order to serve exceptional coffee in the cup, the beans need to be of exceptional quality. Best of all, the farmer receives more money for these premium beans hence every bean counts!

will at the mill