Coffee is a cherry. That is nothing new. It’s also a huge business. Coffee is not, contrary to a (very) stubborn myth, the second most traded commodity in the world. Mark Pendergrast, who put the line into print in his first print run of Uncommon Grounds, has since acknowledged the misattribution and tried to rescind it in subsequent runs, but it remains stubbornly present. It is up there though and hugely impacts a massive number of people in many countries around the globe.
Coffee at the business end – green or roasted – is a business governed by weight. When picked it is a cherry, and throughout its journey it is losing weight, either through moisture loss or losing matter. It’s also gaining value as it moves downstream, but part of that is a concentration of cost. Some of that waste can be utilised elsewhere and it’s a simplification to just think of the cost of that bean, but the reality is that nothing really carries the weight of the expenses like the bean itself.
The question then becomes, just exactly what does that weight loss look like?
We will encounter a few variables which are somewhat smoothed out for ease. Each varietal can vary in pulp quantity, each tree in yield, and grading itself by definition adds cost too. The sorting of higher grades creates lower grades, and lower grades still sell, being an important part of the total make up of a year’s sales. Those costs at each point involve human labour, infrastructure, land, fuel, administration and more. This is not a detailed breakdown of the entire cost structure but it is important to know that they are there, and they too are subject to pressures in the same way as any of our businesses are. The weights are representative, not precision, but will hold true across the industry as a whole.
The cherry then, where our journey begins. Fully ripe, swollen, deep red, freshly picked. A bag full of them, alongside the slightly overripes, slightly under. A leaf or three. Different countries will collect in different volumes, primarily as a way for accounting for the labour, but the end result is the same in processing and leaves us with a lot of picked cherries. For mathematical ease, we will assume there is 100kg.
Cherries being moved at the mill
The Wet Mill
First step for picked cherry is flotation, or cleaning of that cherry. It will remove the sticks, leaves and general dirt as well as cherries that have a lower density. A small note that in Brazil, sometimes the floaters make the best coffees – if they are dried on tree, then the dynamics can change. This is not that story.
What we end with is a cleaned cherry, ready for further processing. The weight has dropped by 2-10% (this will vary with pickers, pest infestations and weather events, let’s say 5% for this example) and our first concentration has occurred. Next, we pulp the coffee. Here, around 40-50% of the weight is lost. This is the skin and pulp of the cherry and reduces our load from around 95kg to between 57kg and 48kg. Assuming the latter. that 48kg gets washed and dried, from a moisture content in the bean of around 50% to 11%, knocking out around another 50% and taking us from 48kg to 24kg. Regardless of the precise measurement at each step, we arrive at the same end point, 24kg, across the various methodologies. That means, to the point that we have dried parchment coffee, we have lost around 76% of the cherry’s total weight already, and we are not even out the wet mill.
Remaining mass per 100kg of picked cherry, showing both actual weight, and % loss between preceding stage. Total loss between full cherry and roasted bean is around 85%
The Dry Mill
The dry mill receives that dried parchment coffee and needs to prepare it for export. First is the removal of the parchment, which can take as much as 20% of the weight off the dried beans. 24kg becomes 19kg. Then, we sort the beans, removing the blacks, sours, and any other defects the grade does not allow for. This can be given at around 10-15% for a reasonable quality coffee, slightly less using industry figures or more towards the mass market grades. The higher quality grades cull more, the commercial cull less.
Ready for bagging then and actual export, our picked cherry mass has dropped from 100kg to somewhere around 16-18kg. Not even a bag.
Roasting
Let’s assume then that 17kg has landed at our roastery, and is roasted. This further reduces that volume through mostly moisture loss by 16% or so, more typically given as a range of 14%-18% depending on style. Depending on where you exactly pitch your variables, that’s somewhere around 13.5kg to 15kg from 100kg of fresh coffee cherries picked, that results in the coffee that sits in our grinder.
The Fine Print
Now, the caveats, because of course there are some. We have covered here wet processing. Dry processing will still result in the same moisture drops but of course, these are at different stages. If you are machine harvesting, this can be highly dependent on how you are machine harvesting. You can see why, when looking at the weight losses, it is so important to be careful in the machine picking and not just stripping. Knowing the ripeness mix on the trees you are about to pick from is vital, as you cannot (yet) instruct a machine to pick ripe cherries only. If you strip pick, then that initial mix of ripeness will add loss through sorting and therefore cost, not remove it. If the cherry has dried on the branches though, that loss has already occurred, and the weight shifts less. Canephora, too, has a thicker pulp, so your weight loss is higher, not lower. Coffee picking is not a straightforward thing.
We’ve used moisture at 11% here, as it is a good balance between maintaining the viability of the bean and making sure it will not spoil. Every change in moisture is weight though, and whilst that may seem quiet for a single bean, it compounds pretty quickly across a harvest. A percentage point either way, across 20tonnes of green, is 200kg of coffee that either is or isn’t there. The industry runs on figures that look small until you scale them, and weight is the one that doesn’t care which side of the chain you sit on.
