Over the last decade, the coffee industry has evolved. Speciality coffee businesses that have opened up since the turn of the millennium are now in the throes of their “third wave” — a time to enjoy higher quality coffee and experiment with innovative processing methods. 

Coffee beans that once would have been considered faulty or defective have now become bestsellers. Furthermore, new processes such as extended fermentations, carbonic maceration, naturals, honeys, and frozen coffee are challenging the market standards. As a result, the guidelines for evaluating green coffee beans must be updated. 

Currently, the standard rules for grading green coffee are limited and outdated: they apply only to washed coffee. However, this is just one coffee processing method. The traditional, widely accepted protocol doesn’t work for processed beans.

So, we’re here to tell you what to look for when buying green coffee beans. Well, more accurately, how to buy raw coffee beans and what to keep an eye out for when you’re buying special processed green coffee that hasn’t been washed and explain why this, in turn, could boost your own coffee business.

What are the Different Green Coffee Processing Methods?

Raw, unroasted coffee can be processed in a variety of ways, including: 

• Washed: the most common processing method in places like Colombia where coffee farmers don’t have to worry about water shortages is a process called washing. This is where the beans are removed from the cherries and are then washed to remove the mucilage or “honey” that is around the bean.  
• Natural: also known as the dry process, naturally processed coffee is where the beans are left with the fruit on them to dry undisturbed. This is the most eco-friendly way to process green coffee and common in countries where water scarcity is more prevalent. In countries like Colombia, this process can take months due to cooler temperatures and proximity of harvest seasons to rainy seasons
• Honey: this way of processing produces a uniquely sweet profile that is distinctly found in the flavor of the cup. Honey processed coffee is when coffee cherries are harvested, the cherries and depulped, but then they are dried with the mucilage, or honey, still on the bean.
• Anaerobic fermentation: anaerobic fermentation is when coffee is processed in a sealed tank that deprives the beans of oxygen. The remaining oxygen and carbon dioxide are released using valves. This forces the juices and sugar into the bean and can produce exotic flavors as a result.
• Carbonic maceration: this process has been adapted from wine-making and applied to coffee. Whole coffee cherries are left to ferment in a sealed tank pumped full with carbon-dioxide.
• Frozen: in the past, coffee farmers used to freeze whole coffee cherries to prevent the fermentation process from starting. However, when whole coffee cherries are frozen they actually continue to ferment, producing great flavored coffee.

Processing Green Coffee Sorting: What You Need to Know

In our experience, standard best practices for green coffee sorting can lead to you discarding some of the best, most flavorful coffee beans!

Instead of identifying defective coffee beans and discarding them right away, coffee buyers should aim to see the nuances in the sorting process. 

For instance, colors and natural occurrences that would normally suggest beans are faulty don’t necessarily mean they should be discarded from the get-go. 

First, here’s a control sample for you to get a feel for the color of regular green coffee beans.

As these beans are processed in different ways, some of them might change color. Some will likely be defective, but not all of them. Others could appear defective, but instead taste far from it. In fact, these will be the beans giving the coffee its most powerful flavor. Here are some examples:

Sour Beans

Sour beans, which have a brown to light brown discoloration, will likely add acidic taste to the coffee cup. However, not all beans that follow these color characteristics are actually sour. 

Here is a photo of fermented green coffee beans that have undergone an extended anaerobic fermentation protocol. 

As you can see, among the green beans there are some brown-looking beans that appear to be sour.

However, after scratching off the outer surface of some of the brown coffee beans, many are in fact a vibrant green color underneath. 

If you’re ever in doubt, don’t discard these beans. Cup them to assess whether they are actually sour or not.

Frost-Damaged Beans

Beans damaged by frost tend to appear pale or anaemic, which means they can sometimes lack strong flavor or aroma.

However, this color change doesn’t necessarily mean your coffee beans will taste bad. Try not to discard these as defective based on their appearance, and wait until you taste them instead to see if they are the result of the process.

Black Beans

In this photo, some of the coffee beans have darkened so much that they appear to be black. 

Some of the easiest defective beans to spot, black coffee beans tend to have a sour taste. 

However, while some coffee beans appear to have a black exterior, you’ll often find that scraping them with your fingernail will reveal a green bean underneath. These beans are not defective and should be cupped to see what they taste like. They could turn out to be some of the best!

Like with all processes, there are also inevitable, unavoidable hiccups which could happen but won’t necessarily affect your whole bean batch if you don’t take them out. Here are a few: 

Broken Beans

When it comes to broken beans, traditional guidelines indicate that they have been damaged by machinery so should therefore be discarded. 

However, when milling natural coffee, beans can break often, as the machinery tends to be stronger and will treat them less delicately. Ultimately, these broken beans will roast differently to the rest of the batch. 

If your batch is small, however, having a few broken beans doesn’t mean all of them should be discarded. Broken beans can easily be picked out.

Husks

Too many pieces of husk in your batch of green coffee could give it an earthy taste or cause a fire risk when roasting.  However, if there are only a few husks in your batch of beans, don’t disqualify your batch. See if you can pick them out.

Remember, coffee is an agricultural product! It comes from farms which are a rustic environment, home to animals and wildlife. Think of it like finding some dirt in your salad leaves. Would you throw away the whole lettuce? Or would you just wash the dirt off and carry on?

Parchment 

Finding your beans encased in parchment can reduce the intensity of their flavor. However, just as with husks, this often happens. Again, if your batch is small, see if you can pick out the parchment-encased beans by hand, as opposed to disposing of your whole batch. 

Foreign Matter

Remember, coffee is harvested and processed on farms, so bits of foreign matter can often find themselves into your batch of beans.

If left in the batch, pieces of foreign matter could damage the machines you use to roast your beans, but they’re unlikely to affect their flavor. Any foreign matter that arrives in your coffee should be reported to your supplier with as much detail as possible (which sack, photos of the foreign matter) so they can best try to identify why it arrived there and how to avoid it in the future. 

Green Coffee Bean Defects: The Ones You Can’t Ignore

All that considered, there are some defects that will always be bad for your batch of beans.

Furthermore, most of them are unavoidable, If you encounter any of these, you’ll need to discard them no matter what:

• Mouldy beans
• Insect-damaged beans: in Colombia we call these brocca
• Fungal damage
• Shells
• Floating beans
• Immature beans
• Withered beans
• Crystallized/ blue beans

What Can We Learn From This? 

If there’s a moral to this story, then we believe it’s to trust your instincts. In order to sort processed coffee beans, we believe that checking their visual quality is necessary. However, it’s more important to judge the beans quality based on how they smell and taste.

The standard guidelines for the green coffee bean extraction process were created for a reason, and in some cases they do still apply. But not in all cases. 

The truth is, when it comes to processed beans it really is difficult to regiment a protocol to score them, because the practice is simply too subjective. And coffee farmers are making the most of this.

By creating their own rules and experimenting with new processes, farmers are introducing nutty, floral, herbal and even spices into their coffee blends. Some are even fermenting coffee beans with organic materials, or increasing alcoholic notes and intense chocolate tastes into their coffee, which is growing in popularity. 

Because of the lack of guidelines for sorting processed coffee, farmers are going one step further. Is pineapple-flavored coffee too far away from the roots of green coffee to be considered natural anymore? And if not, what’s the limit? Can processed coffee ever become too artificial?

Case Study: La Ventolera Farm, Colombia

Meet Felipe, a coffee farmer from Santa Bárbara, Antioquia, Colombia. During one coffee harvest, Felipe realized that he didn’t have enough space in his African drying beds to ferment and dry his harvest during the highest peaks of the harvest. 

So, he decided to freeze the coffee cherries in order to pause the fermentation until he had space available in the african beds.

However, unbeknownst to him, another fermentation process had begun during the freezing stage. This affected the color of the green coffee beans after he had dried them. 

After they had been dried, some of the beans became sour. Others turned black and red — normally signs of beans that should be discarded according to standard sorting guidelines. 

However, trusting his processing skills and accepting that the batch was never going to be perfect, Felipe found a way to sort these beans that allowed him to control the real defects. 

As a result, he implemented his own sorting protocols in the dry mill to accurately produce a quality product, harvest new flavors of coffee, reduce waste, and put more emphasis on the cupping process.

Had he abided by industry standards, his final product would never have existed. And had his customers sorted his coffee based on industry standards, no one would have been able to enjoy this innovative process.

Closing Thoughts 

The market is still getting used to a level of experimental disruption that is challenging the definition of coffee in many ways.

This experimental boom may create some confusion in the trade market around the difference between a defect and an attribute in coffee beans. And this confusion could be reflected in the way professional cuppers score coffee when they taste it.

As a result, many coffee farmers have stopped promising specific physical qualities in their coffee, and instead, they offer a “profile” of what the coffee should have.

Green coffee sorting is simply too subjective for a protocol, or a system. 

As experienced green coffee suppliers, we believe that checking the visual quality of the beans is necessary. But sometimes, judging them by their physical appearance can mean missing out on some of the tastiest coffee around. 

Defects exist, but at the end of the day, what’s more important is the sensorial experience which allows you to smell, taste, and understand the product as it’s presented to the customer. This requires good skills in cupping, roasting and preparing the coffee itself. 

Wondering where to buy green coffee beans? Look no further. Take a look at our range of Colombian green coffee beans and pick up a sample package of extraordinary coffee today.