Coffee Quality Control- Beginners guide to Coffee cupping.

Green Coffee cupping is the single most important quality control step in the coffee value chain. It involves organoleptic and sensorial analysis of the green coffee samples. Coffee cupping is an industry-standard for quality analysis. This means that everywhere coffee is produced or consumed, cupping happens.

It involves tasting and smelling the coffee to get the basic qualities such as the taste, flavor and fragrance. It is conducted by trained coffee cuppers who are able to distinguish between the various qualities in various coffee samples.

Cupping involves sample roasting and tasting. It is carried out in a quality lab commonly referred to as a coffee quality control lab. Cupping is especially essential in the price discovery of coffee. All green coffee samples are cupped to help in valuation with the high-scoring coffees being more expensive and vice-versa.

Coffee Cupping is also useful for blending and bulking purposes. Coffee millers will cup the received parchment samples to get the quality characteristics of each sample. From the results, all similar parchment lots are bulked to form a millable lot (the minimum number of bags that a miller hulls).

Coffee traders and roasters use cupping for blending purposes, the cupping will give the coffee characteristics from which blends are prepared. Blending is different from bulking in that the coffees do not necessarily have to have similar quality characteristics.

From the green coffee cupping results, very interesting blends are prepared which sometimes increase the value of the samples. The body, acidity, and flavor of the cupped samples will be used when preparing the final blends in which the result will be vastly different quality-wise from the original samples.

Offer samples, Subject To Approval Samples, and Pre-Shipment samples are all cupped by the coffee seller and the buyer to ensure uniformity and similarity to the ordered coffee.

Preparation of the cupping materials.

Cupping for various reasons is pretty much a standard affair. The process of cupping for blending, price discovery, bulking or defect hunting is similar. This means that a standardized process is followed although there might be minimal differences in protocol and approach from different cuppers.

coffee samples for cupping can be fresh or stored for a period of time but the roasted grounds have to be fresh before cupping. This means that cupping will reveal the period coffee has been stored.

Peter Gakuoh cupping coffee

A cupping lab has to be specially prepared for the cupping process. Clearly labeled coffee samples are prepared and placed in trays. Each sample has a unique number that will be used in the cupping forms with all the cupping results. Each green coffee sample has to be analyzed for defects beforehand and recorded. 

Color, size, odor, and appearance are recorded for classification purposes. This will determine the scores of the coffee to be categorized as Specialty, Premium, or Commercial coffees. The higher the number of defects, the lower the scores the coffee achieves.

After green coffee analysis and proper labeling are done, the samples are sample roasted. For best results, a light-medium or medium roast is preferred. This balances the coffee quality characteristics which gives the best results. After roasting, the beans are air-cooled until they attain room temperature.

For best results, the roasting is done within 24 hours of cupping. The roast is then immediately evaluated. The parameters include the roast type such as brilliant, ordinary, dull while the center-cut is categorized as white or bright.

After roast evaluation, the coffee is ground. The best grind type is a standard grind or paper filter grind. The ground coffee is covered well to retain the fragrance and aromatics. The coffee fragrance disappears rather quickly and so, it’s advisable to evaluate the coffee fragrance immediately after grinding.

After grinding each sample, it is advisable to clean/flush the grinder to avoid mixing two different samples. The grounds are then placed in cupping bowls for evaluation. Depending on the protocol, some cuppers use two or three bowls for consistency purposes. After evaluating the coffee fragrance, the results are recorded and the fragrance can be floral, or nutty.

The cupping table should be clearly lit and clean with no perfumes or smelly equipment around. It is also advisable to do cupping sessions before meals or sometimes after brushing the teeth to avoid compromising the evaluation. 

The tables have clean cupping bowls, cupping spoons, sample trays, spittoons, towels, kettles and clean water heating equipment. The water being used should be heated to 92^o ~ 93^oC. The cupping spoons should also be dipped in warm water to maintain room temperature.

All the green coffee sample trays that are clearly labeled should be placed alongside the corresponding roast and the grounds. Some cuppers place the green coffee and the roast in different-colored trays for easy identification. Heated water is placed in clean kettles and poured onto the cupping bowls with the grounds.

For every cupping bowl, 150 ml of water is added to the 9 grams of coffee grounds inside. The 9 grams are weighed for the whole roasted bean. This is the recommended ratio by SCA.

 The water is added such that it covers all the grounds completely. After pouring the water on all the cupping bowls, a timer is started.

A standard waiting time is 4 minutes. After the time has lapsed, breaking the crust follows. This is where the grounds that lay at the top of the bowls are pushed to the bottom of the bowl. This is done using the cupping spoons until all the grounds sink and only a foam/froth remains at the top. At this point, the aroma is evaluated. Aroma is the smell of the infused grounds. This is done by smelling the coffee as the crust gets broken while recording the observations.

Cleaning the cup follows where the foam that remains at the top of the cupping bowls is removed. This is achieved by using two cupping spoons and scooping the foam until only clean coffee at the top remains. Between each sample, the spoons are rinsed in hot clean water to avoid mixing the two samples.

After the coffee cools down, the cupping panel starts cupping through the tongue. This is achieved by scooping a spoonful of the coffee and slurping it into the mouth. This slurping motion allows the entire scoop to spread evenly on the palate to distinguish between the various flavors, body, and acidity.

After evaluating the cup with the tongue, the coffee is spat out into a spittoon. After each slurping, the cupper records his findings which include the body, flavor, acidity, uniformity, and balance, and moves on to the next cup. In between each cup, the cupper cleans the spoon and his mouth by drinking a little amount of water to wash off any lingering coffee.

Cupping Results.

After each and every cup has been evaluated, the following aspects of the coffee are discovered: Flavour, Acidity, Body, Aftertaste, Balance, Clean Cup, Defects, and Overall.

Fragrance and Aroma refers to the smell of dry grounds before brewing, revealing potential aromatics while is the smell of brewed coffee, indicating its unique qualities. Both help assess coffee quality and origin, guiding sourcing and roasting decisions.

Flavor is how the coffee tastes. This can be salty, sweet, bitter, or sour.

Acidity is the sharp, tingly feeling that coffee has. Different from bitterness, acidity can be bright for the really sharp coffees or muted or lacking.

Body is the “weight” or viscosity that coffee possesses. For the “heavy on the tongue” coffee, the body is described as being a full body. Can also be lacking or flat.

Uniformity uniformity is consistent quality in unroasted beans for reliable flavor. It ensures even roasting and predictable taste in brewed coffee, essential for a consistent consumer experience.

Aftertaste is the lingering taste at the back of the mouth. It can be pleasant, floral, or bitter. It is a crucial characteristic, especially for coffee consumers. Consumers are always looking for coffee with unforgettable aftertastes.

Balance is described as the harmony between the above qualities. Well-balanced coffees combine all the above aspects into one great cup of coffee. If one of the above aspects doesn’t align with the rest, the coffee is unbalanced.

Cleancup is the overall perception of the cupper depending on how smooth the coffee feels.

Overall is the overall and ultimate conclusion of the coffee cup quality.

Scoring.

There can be many other aspects of the cup that may be evaluated depending on the green coffee cupping requirements and the purpose. After adding up and getting the average score of the cups, the resulting figure determines the coffee level. It can be Specialty 90 – 100, Premium 85 – 89 or Commodity / Commercial coffee 80 – 84. Coffees that score below this are referred to as Not Specialty. 

All the above points are recorded on a cupping form. Cupping forms differ from one cupper’s preferences to another. SCA also provides sample cupping forms that are very commonly used. 

It’s very important to prepare adequately before the actual cupping sessions and plan accordingly. To avoid cupper bias, it’s recommended to generate random sample numbers to represent the various samples. 

A discussion to compare notes after the conclusion of the exercise is important. Having an open mind about each sample is crucial to avoid pre-judgment bias and help in appreciating the various quality characteristics of the samples. 

Finally, establishing the main purpose of the cupping session is very essential. This will assist in preparations and panel selection.

Also, learn more about Understanding Green Coffee Sampling