How to assess the quality of coffee

HOW COFFEE IS EVALUATED

Acupping scoredescribes the quality of the beans we choose to make our coffee from . It is the output of a coffee evaluation based on cupping, or tasting. The word "cupping" could be translated as cupping. The idea is to prepare a cup of coffee, which istasted and givena numberbased on how it tastes, smells and other characteristics .

To guarantee a level playing field and relevance in this examination of coffee samples, strict rules andprocedures have been established . In order to ensure that these methods can be followed not only in a specialised laboratory and that standardised cupping can take place, for example, directly at the coffee grower's processing station, a method of preparing a cup of coffee for evaluation has been identified which isnot too demanding on technological equipment. At the same time, the preparation of the cupping is quite simple so that almost anyone can use it, regardless of their barista skills.

Cupping involves asubjective assessment of the following coffee characteristics: aroma, taste, aftertaste, acidity, body, uniformity, balance, cup clarity, sweetness and overall coffee experience. In order to evaluate the coffee on all these important parameters , acupping form is used in which the taster writes his/her impressions of the coffee.

The taster gives his/her feelings, or if you prefer, his/her opinions, in numerical terms, on a scale of6 to 10 points, with no maximum value assigned and a difference of 0,25 points on the rating scale. This scale is used for choice coffees because samples which would be assessed with a score of less than 6, i.e. with a quality less than good, cannot be passed off as choice coffees. These coffees are referred to ascommodity coffees. Only those coffees which score80 or more in the final score are considered to be of a quality. The official standardized evaluation by SCA experts is subject to written and valid cuppingprotocols. These documents specify exactly how cupping is to be conducted.

CUPPING STANDARDS

For cupping, we need a sample of the coffee we want to evaluate, ideally roasted within 24 hours before tasting. These freshly roasted beans should then rest for a minimum of 8 hours.

Proper roasting takes between 8-12 minutes and the result must be free from noticeable scorching. The sample of freshly roasted coffee is immediately cooled to approximately room temperature and stored in a dry, cool and dark place in a sealed container to prevent contamination of the coffee.

Necessary conditions for professional coffee quality assessment are recommended by The Statics and Standards Committee of the Specialty Coffee Association of America.

Essential equipment:

Roasting - Preparation Environment Measurement - preparation
Coffee sample from the roaster Good lighting Scale
Grinder Clean environment Tasting jar with lid
Agtron* Tasting Tables Tasting spoons
Calm Hot water device
Comfort temperature Required forms
Avoidance of distractions (telephone, etc.) Writing utensils

*Agtron is used to scale up roasting. The device, using infrared light, measures the degree of roasting.

Standard cupping containers are bowls or cups made of tempered glass or ceramic with a capacity of207 - 266 ml. Depending on the size of the bowl, we calculate the correct ratio of water to coffee. The optimal ratio is 8.25 grams of coffee (+/- 0.25 grams) per 150 ml of water.

This is the weight of whole, not yet ground roasted coffee beans. These are ground just before cupping, no longer than15 minutes before pouring. Usually cupping is tested with multiple samples. It is important to prepare two batches of coffeefor each sample. It is important to ensure that noparticles from the previous grind get into the sample being tested , the first batch of coffee is ground and only the second is used for the cupping itself .

Theground beans are poured with clean, unsoftened water at 93° andcare is taken when pouring that the water does not fallon the coffee from a height, but is poured as close as possible to the ground coffee and to the surface in the cup. The moment we start pouring the coffee, we watch the time. The coffee is left in the bowl for4 minutes.

Then a spoon (a deeper spoon designed for cupping) is used to break the crust of ground coffee formed on the surface. This is one of the most beautiful moments of cupping, because it is by breaking the crust that the aroma of the coffee develops. Finally, two cupping spoons are used to pick up the coffee particles from the surface and thecoffee in the bowls is ready to be tasted and evaluated. Once the sample has reached a temperature of 70°C, the evaluation should be complete.

SCORES FOR EACH COFFEE ATTRIBUTE

In the cupping form, there are two scalesfor some areas of the assessment . Thehorizontal scale scores thequality of each coffee attribute, while thevertical scale is used to record the intensity of that sensory component for the evaluator.

  • Thearoma is examined as dry andwet, i.e. the aroma of dry ground coffee and the aroma after pouring water. The dry aroma is evaluated by grinding the coffee, when the aromas from the coffee are released in the grinder, and then by smelling the bowl of ground coffee. The wet aroma is most pronounced when breaking the coffee crust.
  • Themain character of the coffee, the taste, is one of the first impressions. It is evoked by the aroma of the coffee and lingers in the mouth even after tasting as an aftertaste. The taste score is the result of the sensation of the intensity, quality and complexity of the combination of flavours.
  • Byaftertaste, we mean the length of the positive taste and aroma sensation that lingers in the mouth.
  • Acidity "brightens" the taste of the coffee. If it is pleasant, it contributes to a feeling of freshness and liveliness. Unpleasant and overly intense acidity can dominate the coffee tasting experience. Itis also assessed whether itreflects the aromatic profile of the sample and the characteristics of its origin.
  • Thebodyquality of the coffee is based on themouthfeel of the liquid. At the same time, body strength is not necessarily indicative of the degree of quality of the characteristic under examination.
  • Theconsistency of flavour in different cups, but using the same coffee sample, is called uniformity. Differences in taste reduce the rating. For each consistent cup,2 points are awarded , up to a maximum of 10 points, for five identical cups.
  • The wayall aspects of the coffee work together to produce a satisfying cup is calledbalance. Its score is reduced if any aspect of the coffee is missing or predominant.
  • Another criterion is the purity of the cup. The sample examined should not contain any distracting or negative impressions. Any cup that is this clean will be awarded 2 points.
  • Ascore of2 points is also awarded for any cup that has asweetness. A pleasant sensation of fullness of flavour, the opposite of which may be astringent 'green' taste.
  • A coffee that hasmet the expectations of due to its character andits own origin will score highly in the overall sensationrating .
  • Finally , thedefects ofthe coffee are counted in two steps . First, it looks for how many samples had a noticeable but not major unpleasantness in the taste, which tends to be mostly in the aromatic aspects of the coffee. Next, the taster focuses on the undesirable flavor, but this must be classified as a defect and described. The first type of defect is scored 2 points and the second 4 points. This score is multiplied by the number of cups where the defect was found. The result is subtracted from the overall cupping score.

EVALUATION AIDS

To investigate the flavours and aromas of coffee, scientists and coffee experts have compiled various aids to clarify and make our perception of coffee flavours and aromas clearer. The most widely used aid to define what we smell in coffee is thecoffee flavour wheel. It is a circular diagram showing the most common flavours we can find in coffee. They are in a logical, sequential order and marked with colors that support the perception ofthese flavors .

This flavor wheel published by the SCA was created based on theSensory Lexicon. This was written by experts from World Coffee Research and is freely downloadable from their website. The Sensory Lexicon is a dictionary of the universal language of sensory qualities of coffee and a tool to measure them. It describes the flavours, aromas andtextures contained in coffee. These coffee experiences that we perceive come from a set of chemicals determined by the genes of the seed, the terroir and the overall processing of the coffee from the origin of the fruit to the cup. Because coffee is one of the most chemically complex foods, the sensory lexicon helps us identify and define the flavors when we consume it.

S CA protocols include standards for the evaluation of green coffee not yet roasted. They look for defects in a sample of 350 grams of coffee. The moisture content of the green beans is also measured, mainly for microbiological reasons.

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