January 18, 2017

Why Specialty Naturals Need Strict Quality Control


Natural coffees are full of sweetness, eco-friendly, and on trend. But they can also be one of the most vulnerable to contamination and fermentation – making them a risk for producers.

Carlos Pola started specializing in natural processing just two years ago, with the support of Alejandro Alegría Pacas. At Micro Festival El Salvador, we spoke to them to find out the pros and cons of this method, and how they ensure good quality control at every stage.

Spanish Version: Por qué Los Naturales de Especialidad Requieren de un Estricto Control de Calidad

Carlos Pola

A cupping session at one of Carlos Pola’s farms. Credit: Carlos Pola

What Is Natural Processing?

Coffee isn’t a bean. It’s a seed. And the coffee cherry has several layers, with two seeds – the beans – nestled inside (unless it’s a peaberry, in which case you’ll find just one bean).

During coffee processing, these layers are removed and the beans dry out, ready to be roasted. There are multiple ways to process coffee: natural/dry, wet/washed, honey, pulped natural, wet hulled… The most common, however, are washed and natural, followed by honey.

Natural processing is, in theory, the most simple method: place the beans on beds or patios to dry, and waiting for them to dry. Then a hulling machine removes the dried cherry and the beans are ready to grade, sort, and roast. Unlike all the other methods, no water is required.

drying cherries

Natural coffees drying. Credit: @dije_ape

Why Choose Natural Processing?

Carlos doesn’t just process natural coffee; he also experiments with honey. But it’s his naturals that, in just two years, he’s become known for.

There are many reasons why he chose natural processing. It uses less water than all the other methods, making it sustainable in the long term. He also tells me he can play with variables such as sun exposure, moisture level, shade, and more.

Alejandro tells me that, before Carlos switched to natural processing, his coffees were scoring 79–80. Now they’re cupping at 84–85. It’s not all due to processing; he’s constantly experimenting to find better production methods. He also benefits from the high altitude of his farms (1,200, and 1,650, and 1,700 m.a.s.l.), which increases the sugars in his coffee – something natural processing accentuates.

But this is still a dramatic increase in a short amount of time. What`s more, Carlos is aware of a growing market demand for natural and semi-washed coffees. While trends can change over time, for now he believes it makes his coffees more competitive.

These two factors combined means Carlos sees greater profits – and can also take on more workers.

Carlos Pola farm

The view from one of Carlos Pola’s farms. Credit: Carlos Pola

The Risks of Natural Processing

Natural processing comes with risks, however – ones that can have a serious impact on producers.

Carlos tells me that climate change has lead to sudden rains and strong winds. Normally, the harvest season in El Salvador is dry; this year, it was marked by torrential downpours (something we saw for ourselves during the festival).

Sudden rainfall during harvest can cause problems for any coffee farmer. Alejandro tells me that too much water can accumulate in the cherry. This can cause cherries still on the branch to split, or drying ones to ferment.

Natural processing, however, requires a lot of sun to dry. These coffees are particularly vulnerable to moisture. Protecting them from unexpected rain is a challenge – one that Carlos Pacas has approached with logistics and through the attentiveness of his workers.

But for producers who cannot guarantee these quality control measures, natural processed coffees can be a bigger risk than washed or honey. Quality can be less predictable; contamination a greater risk.

drying coffee

Unshaded natural coffees. Credit: Phil Beattie

Quality Controls for Natural Processed Coffee

I asked Alejandro to talk me through quality control measures at each stage, and how that ensures high-cupping coffees.

  • Picking

On Carlos’ farm, pickers are careful to only pick wine-red cherries. This is the colour of ripe, coffees (unless, for example, you’re cultivating Orange Bourbon or Yellow Catuai). As the coffee ripens, sugars develop to create the best flavors.

Alejandro also says that it’s crucial for workers to understand the physical changes the cherries go through. He tells me that if they squeeze a cherry and count how many drops escape, they can see how much mucilage there is. Higher levels of mucilage mean better tasting-coffee, with one study finding that it can account for 20% of the variability in the cupping score. Alejandro tells me that more than three drops is a good sign.  

After picking, Carlos and his team then measure the cherries’ weight and density in a one-liter container. The results are split by varietal so that they can be compared, and notes on the yield are kept on record.

coffee cherries

Ripe coffee cherries ready to be picked. Credit: Carlos Pola

  • Raised Beds

Carlos’ coffee cherries are hand-sorted before and after being placed on raised beds. Workers must remove any unripe cherries, and look for any that have coffee berry borer (broca) holes.

Raised beds allow the cherries to remain on a clean surface, with wind circulating and helping them to dry evenly. It’s crucial that the cherries are kept in thin layers, and regularly moved, to ensure an even drying.

Alejandro recommends using your hands to move the cherries, and tells me that farmers should think about the size of their beds: when Carlos opted for smaller ones, he saw better cupping scores.

“When [the beds] are too big, you will have to use something to move the coffee in the center,” Alejandro explains. “The chances are low that the coffee will dry evenly.”

  • The Drying Period

For the first three days, the cherries are left exposed to the sun and cold night. After the third day, Carlos and Alejandro shade them between 12 and 2 pm, when the day is its hottest. It’s important to leave space on the beds for airflow, Alejandro tells me, while the coffee is being shaded.

After 20-25 days of this, Carlos’ coffee will reach its ideal moisture level – which Alejandro tells me is 10.5% for natural coffees, not the more commonly cited 11-12%. He explains that the high levels of sugars, which are still reacting inside the cherries, means the risk of over-fermentation is greater.

Carlos uses a moisture meter to check his coffee. He calibrates it with neighbouring farms and the Consejo Salvadoreño del Café. “People often make mistakes when they don’t [calibrate] their equipment,” says Alejandro, who also recommends measuring the moisture level at the coldest moment of the day for greater accuracy.

natural processed coffee

Natural coffees. Credit: The Missing Bean

SEE ALSO: Why Plant Coffee in Rows?

  • Cherry Storage

When it’s time for storage, the coffee cherries are placed in GrainPro bags to protect them from insects. They are then stored in a warehouse, out of direct lights. Raised wooden patios keep the bags off the floor. The moisture content (60–65%) and temperature (19ºC–25ºC) inside the warehouse is carefully controlled.

Alejandro tells me that it will take, on average, three months for the coffee to be ready to export. It will continue to stabilise during this time, he explains: any herbal notes will disappear and the acidity and sweetness will continue to develop.

During this time, if the moisture level rises above 10.5%, Alejandro tells me there is a risk of over-fermentation. And so every week, he cups samples to look for possible defects or imperfections.

natural processed coffee

Natural coffees, before and after drying. Credit: Big Island Coffee Roasters

Natural coffees have a reputation for being the easiest to process. But great coffee doesn’t happen without significant investment. And specialty-grade naturals are no exception.

Carlos is driven by the need to continuously improve. For him, all this hard work and effort is worth it when he tastes the results.

With thanks to Carlos Pola and Alejandro Alegría Pacas for talking.

Perfect Daily Grind

Want to take part in more discussions like this? We’re going to Brazil for Micro Coffee Festival 2017! Learn more or buy your ticket here!