What's the worst phone call an importer can receive? It's that dreaded phone call from a roasting client letting you know that the arrival sample of a full container shipment (we are talking somewhere between 33,000-45,000 pounds of coffee) is defective and that they can't accept the delivery. I recently received one of these phone calls so the experience is fresh painfully fresh in my mind.

In cases like this what usually happens is: a coffee lot has been approved as a pre-shipment sample (PSS) by the importer and by their roasting client (if the coffee is pre­sold) and a full container of the coffee lot is shipped based upon this approved PSS sample. When the coffee arrives, both the importer and roaster are also going to approve an arrival sample and, in most cases, this is a formality. Of course, there can be subtle changes to a coffee lot between approval of the PSS sample and arrival of the container, but most often coffees arrive as expected. In fact, sometimes green coffee may actually improve as the coffee receives more resting time during transit where flavors further develop and even out amongst the lot. However, when a coffee lot does not arrive as expected and, is in fact, rejected as either fully defective or even just different enough to be classified as "not to specification," everyone begins scrambling and nobody ever wins.

So, what happens in these circumstances between approval of a coffee lot before shipment and delivery? How can a coffee that has made it all the way through growing, harvesting and processing as a top-grade specialty coffee transform from specialty to defective post processing? If you've been reading previous articles in this series, you will recall that there are many different problems that can occur during the vast and complicated stages of growing, harvesting and processing and that it takes tremendous skill, dedication and even some luck to get quality coffee through this long, labor­intensive chain. So, truly, it is heartbreaking when something goes wrong so late in the game.

As Martin Diedrich, owner of Kean Coffee in Los Angeles, stated when discussing his experience in receiving delivery of a drastically diminished Zimbabwe coffee, "it was a huge loss for us and a blow to the farmer as well." In this circumstance, Diedrich reported that he had been buying this top-quality coffee from the same faun for many years with excellent deliveries every time, but that this time, something happened between his approval of the PSS sample and arrival of the coffee into the states. I-laving worked with the farm for nearly 14 years, Diedrich had no doubts that the right coffee was shipped to him and that the producer followed quality protocols diligently to the final points of influence; hut, nonetheless, the coffee was drastically diminished. Although not technically fully defective, it was "a shadow of its former self," according to Diedrich and unusable as a specialty grade single-origin coffee. This type of tragedy or worse---is what we are going to examine in this last article in our series on green coffee defects.

Catagories of Post-Processing Defects

Defects created post-processing are best categorized by their root causes. First, there are those defects caused by naturally occurring latent internal changes in the green bean likely due to problems during drying. (If you recall from part three in our series, proper drying of green coffee is extremely important.) Second, external conditions after processing, such as heat, moisture, and humidity, grouped together as the "general climatic conditions during the resting process" by Stefan Wille, general manager, Coricafe, Costa Rica can degrade or even drastically transform green coffee during storage or shipping. Third, external contaminants, including pests and highly odorous substances, can destroy coffee quality.

To better understand post processing defects and their ramifications on green coffee quality, we're going to take a closer look at each one of the categories above.

Internal Changes Post Processing

The first category--latent naturally occurring internal changes--is probably the most challenging of post-processing defects to understand and trace because something has gone wrong earlier in processing that causes degradation of the green coffee later even when the climatic and environmental conditions post processing arc controlled properly. In these cases, the green coffee was improperly dried--either not dried enough or inconsistently dried---so the green coffee retains too much internal humidity. Green coffee with high internal humidity may develop fungus damage, leading to "mold and earthy tastes," according to Wille. In extreme cases, the green beans will grow mold on the exterior, so they are easily identified visually even before tasting. In addition, green coffee retaining high moisture may continue to fennent, which will lead to, yes, you've got it: over tennentation. Remember the glorious flavors of rotten fruit we've talked about throughout this series? They can develop this late in the game even if carefully avoided at all other stages.

External Climatic Conditions

Because of a highly hygroscopic nature, even properly dried green coffee can develop a variety of defects after processing if climatic conditions are not managed properly. At all times, green coffee must be stored in appropriate conditions that control temperature and humidity or the same defects that occur from improper initial drying can develop. (We'll review proper storage conditions under prevention strategies.) Both too much and too little moisture can contribute to significant deterioration in quality.

In addition to the possibility for overfennentation, fungus, and mold, conditions in storage and transit that create excessive moisture may cause spongy/faded/whitish beans and white beans. Spongy/faded/whitish beans are, unsurprisingly, whitish in color and have a consistency like cork, caused by enzymatic activity due to excessive moisture; they may pick up woody or cereal notes in the cup. White beans, caused by bacteria developed in high moisture, range in color from pale green to white, but maintain a normal density. According to Jorge Pacas, agronomist in El Borbollon, El Salvador, "in the cup, they will have baggy flavor or old crop flavor."

On the other side of the moisture equation, environmental circumstances that cause coffee beans to lose moisture can be equally detrimental to quality. If warehouse temperatures become too hot, for example, internal moisture within the green bean may reduce below an acceptable level (absolute minimum 9 percent; ideal 12 percent), causing the beans to, "lose all of their flavor and aroma due to evaporation of the oils", states Pacas, or in more extreme cases, to develop "woody and oldish [flavors]," according to Wille.

Contamination

Some of the most dramatic post­processing defects occur by contamination. For example, green coffee that is stored near or exposed to contaminants like "oil, diesel, gas, pesticides, and smoke," as identified by Pacas, can infect green coffee due to the highly absorbent nature of green beans, which easily pick up odors from surrounding materials and products.

One of the most dramatic examples of a contamination problem occurred with coffees from the Honduras 2006 Cup of Excellence (COE). As most of us know, COE coffees are some of the best in the world, having been scrupulously selected through a national and international jury process to reflect the very best coffee in a given country each year. Unfortunately, in Honduras in 2006, the winning coffees were contaminated and largely destroyed after processing. According to Susie Spindler, executive director of the Alliance for Coffee Excellence, "the jute bags were made with a petroleum substance that permeated the jute and tainted the coffee" in some cases so significantly that the coffee was "god-awful."

It may seem obvious to most of us that no food product let alone one as absorptive as green coffee-­should be packaged in materials containing petroleum or other harmful chemicals, but it is not an exclusive case. Diedrich also recalled a situation in Kenya a number of years back where the paint used on the coffee bags contaminated the green beans. In this case, fortunately, the paint was not ultimately significantly harmful to the taste profile and most of the damage was visual.

Another external contamination defect transpires when pests invade beans in storage. Typically, the guilty party is the coffee bean weevil (Araecerus fasciculatus). Beans that are subjected to the weevil will exhibit uneven holes larger than 1.5 mm. The extent of this damage can vary from slight to heavy and, in worst cases, a full infestation can occur and live and dead insects may still be found with the beans. Impact on the cup can include noticeable off-flavors and diminishment of aromatics and acidity.

Fixes

Undoubtedly, everyone managing green coffee will agree that post processing defects/quality loss are very unfortunate. Certainly, producers, millers, importers, shipping lines and warehouse managers should do everything possible to prevent situations where these defects can develop and, in most cases, they do. Nonetheless, it is not always possible and, unfortunately, like many other defects we've discussed throughout this series, post processing defects generally cannot be reversed or fixed after they've occurred. On the financial side, producers and importers are likely insured for some of the direct financial loss in these situations; but, depending upon the circumstances, this is not always the case, so serious financial loss can occur. Even more challenging than financial losses, however, is the challenge faced by importers trying to ensure that their roasting clients still get the coffee they need when they need it.

Fortunately, in some less severe quality loss cases, it may be possible for a roaster to still use a diminished coffee. In the best-case scenarios, where the problem is minor to notable flavor degradation but not an actual defect, producers, importers and roasters often try to work together to come up with a solution that will work for all parties, a solution that hopefully doesn't result in a full container being rejected back to the importer or, even worse, the producer. For example, if a roaster can utilize the coffee in another capacity, perhaps in a blend, then the importer may offer a discount off of the original price to reflect the quality difference. Depending upon when and how the problem occurred, the importer may or may not go back to the producer and request a similar price adjustment. In most of these cases, this loss cannot be recovered by an insurance company, so the financial adjustment loss is covered by the importer/exporter producer out of pocket, which is part of the risk that exporters and importers manage.

In more difficult circumstances where a coffee cannot be used by the roaster, the importer has the responsibility to replace the coffee, which is never an easy process and can sometimes lead to a mad and even impossible scramble if the particular coffee is in short supply. In worst-case scenarios, an importer may not be able to find a replacement and so the entire sale is canceled, which is certainly a financial loss for the importer and potentially a disaster for the roaster, who does not have the coffee they need to meet their sales.

In the case of the Honduras COE coffees contaminated by petroleurn­laced bags, there was great variability in how the coffee was dealt with. As Spindler recalls, "even within one lot, one whole bag was perfect, one was god-awful, and another one may have been off, but not completely tainted." Due to this inconsistency, there was no single solution to managing the problem. In Europe and Japan, buyers were willing to sample and test each bag individually, which yielded the best possible results for producers, who were able to get full price on some bags and discounted pricing on others where possible. Interestingly, Spindler reported that the U.S. market was apparently not willing to go to the same lengths, so the U.S. lots were rejected in full.

Given the extensive challenges in replacing defective coffee after shipment and the barely adequate fixes that exist, it seems most important for efforts to be focused on prevention methods.

Prevention/Proper Storage Conditions

Prevention of post processing defects requires protection from contaminants, proper initial drying, and maintenance of ideal conditions at all times during storage and shipping. We reviewed proper drying in the last article in this series (see Roast, May/June 2008) and avoiding contaminants is fairly self­explanatory (not to presume always easy or possible), but what are ideal conditions for green coffee during storage and transit?

According to Douglas Martocci Jr., vice president of Continental Terminals, Inc., in Kearny, N.J., "warehouses should maintain an ideal green coffee storage temperature of 45-85° F and a relative humidity of 50-55 percent. When held at the ideal storage temperature and humidity levels (45-85° F and relative humidity of 50-55 percent), the green coffee should not experience more than a one percent variation in moisture levels." When these conditions are maintained, green coffee is generally protected from quality degradation beyond the gradual and natural decline of green coffee post processing. Green coffee warehouses are also generally devoted strictly to green coffee, so risk of contamination from other products is minimized and warehouse managers, like Martocci, are experts at managing green coffee storage conditions.

These same conditions applied at Continental and other coffee warehouses should ideally be applied to green coffee at all times after processing, which means that export warehouses should strive for similar conditions before shipment (often difficult for poor producing countries) and shipping vessels ideally provide similar conditions.

Interestingly, according to Ming Chen, operations manager for Marco Polo Enterprises, Calif., a freight forwarding company that manages coffee cargo by Ocean and air freight, green coffee is not shipped under such strict conditions, though. "We ship coffee beans as general cargo since it is not required to have temperature control," Chen states, adding that their company has not yet had any claims for loss of quality in transit. So perhaps the conditions of the average vessel are sufficient for protecting green coffee, but uncontrolled shipping conditions certainly risk harm and, in some cases, are assuredly the cause of containers of high­quality coffee arriving significantly reduced in quality or outright defective.

One newer idea to protect against variants and un-controllability in export warehouse and shipping environments is the use of valve/ vacuum packaging. Daterra, producers of specialty coffee in Brazil, have been successfully packaging their top-end green coffee in valve packaging for a number of years and it is now becoming an option in a number of other producing countries as well. This type of packaging protects coffee against contaminants and creates an environment where there is "less moisture variance" as Spindler puts it when revealing that COE is moving to this type of packaging where possible. Roasters are catching on to the concept and some roasters, like 49th Parallel in Canada, are starting to request that their importers move towards providuig valve packaging for all of their top-quality specialty coffees. Although I have concerns about the environmental ramifications of packaging coffee this way across the board, it does seem to be a logical and worthwhile option for expensive auction and micro lot coffees in particular.

Wrapping Up

For those of you who have been reading along in my Detecting Defects series, this is it. This is the end of defects. OK, that's not true-A can't actually do anything to end the defects in the world of green coffee, but I do hope that this series of articles has illuminated some prevention, identification and, in rare cases, repair strategies useful to roasters. Though I've tried to get in-depth where possible, in many places I've just managed to scratch the surface. I encourage roasters (and importers and producers) to continue learning about defects. If you find a defect on your cupping table, beyond just rejecting and replacing the coffee and covering losses, try to track down where and how the problem occurred. Dialogue with your importers and their producer partners openly about the visual and taste ramifications, the possible causes, and preventative measures for future shipments. Only through knowledge and open communication can we hope to prevent more defects over time. For your final tasting assignment, I recommend brewing up a perfect cup of your current favorite NON-defective coffee to remind you why understanding and ultimately preventing defects is important to you as a roaster. I mean: what if my beautiful El Salvador bourbon coffee were to taste like rotten fish, vinegar or peanut butter? That's just no good.

Footnotes

1 For those of you from my cultural and generational experience, it's not, `have you checked the children? "It's worse.

2 In this article, we are going to include coffee that experiences a significant loss or change in flavor even if the coffee is not ultimately classified as fully defective. In these cases, a noticeable transformation of the green coffee from pre-delivery approval to arrival certainly warrants investigation and better understanding by roasters.

Andi C. Trindle began working as a barista in 1989, and, to her surprise, remains in the specialty coffee industry 18 years later She currently works exactly where she belongs as a green coffee trader with VOLCAFE Specialty Coffee. Andi also consults, lectures and volunteers extensively within the coffee industry both nationally and internationally. She currently serves as President of the International Women's Coffee Alliance and as co-chair of the Cupping Subcommittee for the SCAA Training Committee.

Courtesy : Tea & Coffee Trade Journal

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