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The Value of Calibration

We are part of a vast industry: there are many players and many different people in it who bring different perspectives and experiences and make our job as coffee professionals very colourful and exciting. Everyone has a certain angle when approaching coffee quality: calibration can help us understand each other and communicate with each other efficiently. In this article, I will uncover how you can examine where you stand, what is important to you, your team, and your organisation, and how to use calibration to understand yourself, others, and the wider industry. I will touch on how to calibrate with the SCA heritage form that most of you are already familiar with and give you a few tips to improve your cupping skills and communication.

Identifying your values and expectations

Wherever you are in the distinct roles that exist in our industry, you need to identify what is important for you with regard to quality and why. People living in different parts of the world value different flavours, as their culture favours one thing over another. Two roasters in different cities distant from each other have different markets to please. When you are evaluating a coffee, you need to know what you are looking for, what your expectations are, and what the intended purpose of the coffee is when it reaches the final customer. Note down what attributes you value and think about what your customers might find important- try to put yourself in your customer’s shoes. Shape the internal standards for your organisation in a way that can help find those attributes. Knowing your boundaries and defining what kind of coffees could go into your rejection pile is also very useful. Ensure you communicate these expectations clearly to your suppliers to better collaborate with them.

Example: I have a Roastery and cafe in a small town in England. People here tend to like chocolaty and sweet coffees. Anything that is overly acidic or fruity can be off-putting for them. I prefer Central-South American coffees that are grown in high elevations and good preparation is important to me (correct screen size, minimal to no quakers in the roasted sample)

Knowing the industry standards, learning the basics  

As we learned, there are all sorts of preferences, but in coffee, there is a common language that is essential to learn to better communicate with others in the industry. It is essential that you are clear on how the industry defines quality in coffee and that you know how to measure it.  To be aligned with the industry, it is first important to follow SCA guidelines on grind size, temperature, brew time, brewing ratios etc.   

The SCA sensory courses are a great help for you and your team to gain the basic skills in identifying flavour and aroma and to learn how to use our various senses to evaluate coffee. It’s a good starting point in anyone’s coffee tasting and calibration journey. For many, cupping can be intimidating, and they might not know where to start and may only pick up a few attributes in a coffee at first. Taste and smell are skills that can be trained by just practising, so the key to becoming better is to keep tasting a few coffees daily until you get confident. Coffees from certain countries also have their basic distinctive characteristics that cuppers use to describe them and are well known- for example an Ethiopian coffee is likely be floral and have berry and citrus notes, a Guatemalan will be chocolaty, creamy and sweet. It is best to taste with experienced cuppers regularly to calibrate with them if you have access to people like that. Alternatively, you can attend cupping events like our monthly cupping club Thirsty Thursdays.   

You can learn a lot by listening to what other cuppers say about the coffees and going back to the cups to taste after discussing to see if you find something similar. Observing certain patterns and noticing commonalities will get you closer to being more confident: after a while of cupping with others, you can pick up what they mean when they say something tastes “green and vegetal” and also what that may mean to them, and what do they mean when they are referring to a winey quality in a Sumatran coffee. It is essential to stay patient: this skill takes time to polish, and your progression depends mainly on what resources you have available, for example: experienced cuppers that you can learn and take advice from, access to different qualities of coffees, how often you get to cup and practice, how consistent you are with your cupping sessions.

Calibration with the heritage form

The cupping form that is most used today is the Heritage cupping form created in the late 90’s and fully adapted by the coffee industry in 2004. Most of you are familiar with this system already: we can score 10 different attributes up to a total score of 100 and individual scores can range from 6-10. In this type of evaluation, we are combining descriptive and affective analysis. The descriptive part is when we describe the coffee’s flavour notes and mark the intensities on the cupping form – this is objective, and we can all agree on these qualities (The aroma was high in intensity, and it was like roses, berries and chocolate). Some descriptors will help you understand whether the intensity of something means a good quality or not. If the body has a high intensity and is rough, the quality is low; often, people would mark the score high if they perceive the brew to be more intense and ignore the roughness. At the same time, if the body’s intensity is low but pleasant and silky, it means high quality, and you should reward it with your numbers.

The scores are the affective part of the cupping sheet: these can be subjective, based on personal bias, feelings or emotion. Cuppers should concentrate on different attributes in each round; certain things are best evaluated at different temperatures. Evaluate Flavour and Aftertaste on the first round, then when the coffee have cooled down to 71-60 degrees C you can rate Acidity, Body, and Balance on the second round. On the third round, check if you still agree with your scores in each box and mark any movements with an arrow if something has changed (For example, acidity has diminished on cooling, and you reduced the score. In this case an arrow pointing to the left should indicate the negative direction of the move.) The Overall box is for you to express how much you enjoyed the coffee, this is the only place where you can express your opinion or liking for that particular coffee.

During a calibration session, we learn about how the majority are rating each attribute, and we can observe certain patterns. It is best if your scores are aligned with the majority of the group. Observe where you are out of calibration and aim to improve on scoring those attributes to be better in line with the others next time.

When doing a calibration in a group, I recommend using five distinctive coffees from different origins. Ideally, use coffees that have been previously Q-graded for the callibration session so you can compare how close the group is to the Q scores. Hide all coffee information on the session and ensure to conduct a blind cupping. Only reveal further details at the end of the session. I recommend drawing out a table of each attribute on a white board or a large white paper. During the final discussion ,you can mark everybody’s individual scores with a coloured marker. I have used this method on our last Thirsty Thursdays Arabica calibration session, and we could clearly see in which score range most people fell into with each attribute. Have a close look at the table below to see this in detail.

Calibration chart

Having this kind of information visible to everyone is useful and informative as everyone can instantly get feedback on where they can score differently to become closer to their colleagues or peers.

The value of calibration

To summarise the above, calibration can be valuable for many varied reasons. It helps us understand where we stand compared to our industry peers. It helps us get aligned with the industry standards and have a common language we can use to communicate with. We can learn about our strengths and weaknesses and have an understanding about what we need to do to improve ourselves. We can learn about how our perception may differ to someone else. Regular calibration can ensure that we keep ourselves to the standards that we have set and evaluate if those standards are still relevant or need changing.