Sample Roasting for Quality Control

Patrick Dinkins

Sample Rousting plots a narjor part in quality control faro given coffeee importers. As an importer: / spend a huge poi-ion of my dory sample raasling coffees for capping and quality control. In a month, Ire sample rouse hundreds of coffees io obtain iglointaliort. such as flacur and flout bled, and determine i/' they meet specialty requirenrerns.

There is little roost for error while roasting coffee samples for quality control. In fact, in many cases, we sample and cup a coffee two to three times before it reaches the warehouse and eventually the roaster. The process starts at the court" of origin. say Guatemala. The farmer or exporter sends us a lot specific sample for a 250 bag lot of coffee, called a pre-ship sample. ti'orn a specific farm or mill. After we cup that sample, we either approve or deny the coffee. If we approve it, the entire shipment of coffee is sent to the U.S. Once it arrives at a U.S. port- it is sampled again and cupped against the pre-ship and the type samples. (Type samples are the samples of different coffees front different farms within a specific coffee region). If the coffee stays consistent in the Cup, meets quality standards and matches the pre-ship santplc, then it is approved and brought into the warehouse before being shipped to the roaster, It is a long process, but cute that's well worth it in the end. because it ensures the coffee is the quality and consistency that it needs to be. and it gives us a great deal of information about bud\, arena, nuwtltfeel and flavor fists ttc can then share with roasters.

So what does this have to do with you, the roaster? I think that roasters and importers call learn a lot front each other. as we're both truing to reach that ultimate goal of great coffee. when it conies to quality control.. most importers have refined quality control to a very high level. as we make decisions to purchase whole containers based on the cupping results o1' a roast sample that arty be as small as 80 to 100 grants. Thus. we have a solid system in place that roasters can benefit front.

Good Greens

The best place to begin quality control is at the green bean. ideally. your importer should have done a visual inspection, as well as taken a moisture and density reading before you even get the coffee. If you have a good relationship with an importer that you trust. it allows you to skip this step. However, if _you'd like to doublecheck the coffees, are just developing a relationship with your importer or just hate the time and inclination to be more thorough, then here are some simple steps to controlling the quality of your green.

When you get the green beans from your importer. do a visual inspection of the sample to kink km detects in the coffee. Defects include broken beasts, black beans, rocks. twigs and the like. This is one of the easiest things a roaster can do to check the quality' of their coffee. It is easy and you do not need arse special tools: just basic knowled;tc and practice. If the coffee is supposed to be a certain screen size, you should also run in through a set of screens to make sure it meet, the screen-size requirements.

Next, take a moisture reading to determine the moisture content in the coffee. SCAA standards are 10 to 12 percent for washed and 10 to 13 percent for unwashed coffees to be specially grade. The moisture meter that I use is very simple to use: just put the coffee in and you get a reading in a minute or so. It can also test roasted coffee and roasted ground coffee. For ine, this works really well, as it's simple but also accurate, 'I here are other store involved meters out there, ones that use a small oven and the weight of the coffee. 'this process is more accurate, but it is also more tittleconsuming. and the machines themselves are expensive. It's tip to you how much time and ener,y you want to expend on this particular characteristic.

Taking a density reading of the Coffee is also a good idea. The moisture meter I use has an attachment to measure the density of the coffee. There is also a formula that you can use. If you have a Warn scale and a container that is exactly one liter, you can use these to get the volumetric density of grants per liter. If you don't have a cram scale. yon con convert ounces to grants by using his formula: ounces x 28.5 = grams.

The moisture and density of the coffee will give you an idea of how old the coffee is and how it will roast. If the coffee is dry, say below nine percent moisture. it will roast quicker and not as evenly. Roast Rh'/it When importers are roasting for quality control. our roast level is usually much lighter than that used by most roasters. The reason behind this is that the lighter a coffee is roasted. the easier it is to detect defects in the coffee. When roasting for cupping on the green side. in most cases. the coffee is roasted just into first crack or just past this point. Some Brazils are roasted so light they don't even get to this point.

If it is helpful to apply some reference numbers to this level, roast the coffee somewhere in the range of 375 to .385 degrees Fahrenheit with a roast time of seven to nine minutes At this roast level, these qualities of the coffee are very intense: aroma, acidity. body. flavor and aftertaste. Of course the had qualities, if present, are also \cry intense. Bagginess, ferment and mustiness are just a few of the things that we are looking liir. These qualities are grounds for the coffee to he rejected.

There are many different sample roasters out there and all work well_ I miss a tour-barrel gas-flied machete f :tell barrel has its overt airflow and flame control as well as temperature gages. These thins make it easier to be consistent in sample roasting.

If you want to take the plunge and buy a sample roaster, you need to decide on gas or electric. I prefer gas, as I feel that I can control the roasting process better because (he heat is easier to usc. I feel that you get a cleaner roast with gas versus electric elements. One advantage of electric roaster, however, is that you can use it almost anywhere. and you don't have to plumb in a gas line.

Before you stake a decision, I suggest talking to other people in The industry to see what they like and dislike about their sample roasters.

The next step is to practice, practice, practice. and practice (your sample roasting that is). Sample roasting is Just like roasting on your big machine. except that things happen a lot faster here in the small drum. You need to watch the bean development throughout the roast, and keep an eye on the time. You don't want to go to fast or you'll gel uneven roasts and the coffee stay taste scorched or burned. On the other hand, if the roast is too long. the sample will cup out tasting baked.

Keep notes just like you do when you (10 production roasts: this will help you with your consistency and give you reference points on how different coffees roast. I had t, spend a lot of tittle on my machine to get just the right combination of airflow and have in order to get the results that I wanted. Keeping good notes helped the do this.

You will also want to play with different roast levels: this is where you can apply the sample roasting to your own QC. You can roast small batches of coffee to different levels and experiment with profiles as well. Then cup the coffee at the different levels and profiles. This can give you an idea on how to get the most out of the coffee, to bring out the unique qualities of the beans.

One thing I should mention is that whatever kind of machine you roast on. you can do a good job and he consistent as well. You just need to know your roaster and how it roasts.

In order to sample roast well, you need more than an understanding of your roaster: you also need an understanding of the coffee. For Example. new crop coffees are going to roast differently than current crop. New Crop Coffees, as the name implies, are coffees produced in the new season. and they are fresh from the mill. Current crops are coffees that are between new and old crop. For example: coffees from Central America are harvested October through March, and we will not start to see those coffees here in the states until May.

These would be new crop, and coffees that are here from the previous harvest are considered current crop until the new crop arrives. After the new crop arrives. the coffees from the previous harvest are considered old crop. A new crop coffee is going to have more moisture content and be more dense, not to mention fresher. This is going to affect the roast in that the current and past crop coffees may roast quicker, and sometimes more unevenly. You will also find that past crop coffees lend to get a little baggy in the cup.

Different origins roast differently also. For example, Guatemalan collecs are high-grown and much (tenser, while Brazils are lowergrown and softer.

These things all play into being consistent in the roast. giving us the ability to. evaluate the coffee fairly. By consistent. I mean the roast profile is the same every tittle. If 1 am roasting six different Colombians to cup, I want the same roast level for all six coffees. This means the bean color, as well as the roast times, should be consistent. If the roast is different for two or three of the six samples, they will cup differently; thus we cannot get a fair evaluation of the coffee and cannot pick the best ones.

Conciaent Cups

Once your coffee has been sized, measured and roasted to perfection, it's tittle to cup it. This is a subject for a whole different article, but I feel Ihat 1 should talk about it a bit. as it applies to our QC process. As importers, we cup coffee almost every day.

We cup, evaluate. score and discuss what we thought of the coffees on the table. This is the final step, as the choice is made here on whether to buy or reject the coffee. If it is approved, the coffee is put on a boat and sent to the US. If it is rejected, another sample is sent and we start the process over again.

I suggest cupping in the morning before lunch. This is because your ability to taste is at its peak during this time of day, you're hungry, and you are not tasting the spicy Thai food that you had for lunch. I would also suggest that you cup with your employees instead of having just one person doing the cuppings. 'Ibis way you get a few different opinions. We also cup the coffee from very not to almost cold, as many coffees change as they cool, and not always for the better. Ilowcver the opposite can also be true - some officers get better and more complex as they cool.

Working Together

As with many things, managing quality control is easier with two heads instead of one. For this reason. it is beneficial to develop a close relationship with your importer. Not only (toes this make good business sense, it allows you can learn more about the coffees you're buying.

Often. importers have intimate knowledge of their coffees that they can pass on to roasters. Sometimes it's a subtlety in the cup - say that the coffee has an unusual sweetness or fruity quality to it that the roaster can bring out when they roast it.

Importers typically keep detailed logs of the coffees they're testing. Thus, they're also a great resource for current crop coffees, as well as lot- comparisons from past years or any other information that inigin make \our job easier.

Is this coffee new crop. current or past crop?
What do you think of the coffee?
How does it cup?
What are the unique qualities of this coffee?
What country, region and farm is this coffee front?
I lave you bought coffee from this farm bef'orc?
What makes this coffee so good?
Have you cupped this coffee?
Have you brewed this coffee to drink?
What score did you give this coflce?

Never be afraid to ask hard questions about the coffee you are buying. Importers should be willing and able to answer all of these questions, as well as any others you may have about \-our coffee. I would also suggest cupping with your importer if it is possible. That way you can learn first-ham( how they do things. After all. We are all after the same thing. a great cup of coffee. Working together, and sharing our knowledge. brings us one step closer to Oral ultimate goal of quality control.