Taste Evaluation of Green coffee refers to the processed seed of the coffee tree fruit. Coffee is a flowering shrub that produces fruit. The seeds of the fruit are processed, roasted, ground and prepared as an infusion.: Coffee More Bean Samples Prior to Purchase & Use
Presenter: Michael Sivetz, from his SCAA presentation
With so many new small retail and wholesale roasters coming into the trade in the late 1980’s and early 1990’s, it has become pertinent to review the factors influencing green coffee bean purchasing decisions.
The small roaster who buys 10, 20 or 30 bags at a time, or even 50 to 100 bags at a time, bases his decisions on factors quite different from the large roasters who buy container loads (250 bags) or ship loads. These large roasters mass package cans, and now valve bags, or pouches of R&G coffee. They look to lowest prices first and quality second (end product is stale). It is intended here to discuss how and why buying decisions are arrived at and how they should be arrived at, and not to discuss the careless methods often used by both new and old roasters.
The buyer has certain ideas about what he would like to purchase at a particular time. The buyer’s choices are limited to those green coffee brokers he is currently using, presumably with stocks within a few hundred miles of his roaster. The stocks available maynot be as broad as desired, have the quality levels desired, or the amounts sought.
So, the ability to fulfill one’s needs may require larger purchases of a particular type so that inventories will carry over into periods when those types of coffees are not available. Or the prospective buyer, may have to go to brokers located several thousand miles away. Perhaps a substitute coffee may have to be used. Price per pound may be a consideration, but it is usually secondary to quality for most small roasting operations, depending on their competitive market.
In the USA, unfortunately, most green coffee imports in the past have been oriented to volume, and to the standards of large buyers like General Foods or Folger, who are price oriented. Until recently, very few green coffee brokers took the time and effort to go to growing countries to seek out “better than average” quality prepared green coffee beans.
The local small roaster is also pressured by his customers to get dozens of green coffees from various countries, under the false impression that each source will taste different. This is an unfortunate idea, that must be controlled and the buyer educated to the fact that coffee qualities are not designated by national/political boundaries. For example, one can take High Grown, or HG, is a coffee designation that can mean different things in different countries. : High Grown, or HG, is the highest quality Mexican coffee designation but in Nicaragua it means 2nd quality. More coffees with good “washed” Preparation refers to the dry-milling steps of preparing coffee for export: hulling, grading, classifying, sorting.: Preparation refers to the dry-milling steps of preparing coffee for export: hulling, grading, classifying, sorting. Sorting means using density sorters More and patio drying from Colombian coffee is highly marketed and widely available in the US. They have been largely successful at equating the name Colombian Coffee with "Good" Coffee. This is half-true. Colombian can be very balanced, with good More, Central America and even from Kenya is the East African powerhouse of the coffee world. Both in the cup, and the way they run their trade, everything is topnotch.: Kenya is the East African powerhouse of the coffee world. Both More, In terms of the Tanzania coffee character, it belongs to the Central/East African family of washed (wet-processed) coffees, bright (acidy), and mostly aggressively flavorful of which Kenya is certainly the dominant coffee. Peaberries are often More or Zimbabwe, formerly known as lower Rhodesia until independence in 1980, has produced great coffee since production was introduced in the 1960s. Like Zambian coffees, these coffees are often overshadowed by the great East African coffee: More, and neither the public nor most small roasters could tell any significant taste difference. What is being dealt with is psychological, and not factual.
In my view, coffees from Kona coffee comes from farms along the Kona Coast on the Big Island of Hawaii: Kona coffee comes from farms along the Kona Coast on the Big Island of Hawaii. Coffee is grown at elevations More for example, carry a high price (like $5/lb), not because they are better tasting than Colombian Supremos, but because there are only 20,000 bags produced per year, with highcost of labor, and hype related to nostalgia of palms, grass skirts and romanticism. Based on green coffee quality alone, most Kona coffees today are not even as good as-a good Colombian coffee, and are largely blended off with $1/lb Colombians at a 10% level and are sold as Hawaiian “blend” by the exploiters. In so far as green beans from the other islands of The Kona district on the big island of Hawaii produces the best coffee from this state - clean, sweet and mild. : Ah, Hawaii... what a nice place. They grow nuts, fruit, and coffee. The More, those beans, in many cases, are tainted by A defect term referring to harsh, acrid, medicine flavors from Brazilian coffees of the lowest order; named for Rio de Janeiro. Result of continued enzyme activity when coffee beans remain in the fruit and the More taste, which most buyers will not use.
Knowing the In coffee talk, it refers to a coffee-producing region or country; such as, "I was just at origin." Of course "Origin" for most product we use is not a beautiful farm in a temperate climate, More of the green coffee beans, is only the beginning of a long list of properties needed to be known about the coffee beans being considered for purchase. Although, history and tradition can be important factors in the purchase of this agricultural commodity; in the final analysis, it is the roasted bean taste that finalizes the purchase decision. There are so many intervening factors that can alter a potentially sound choice, e.g. weather, The removal of the cherry and parchment from the coffee seed.: Coffee is either wet-processed (also called washed or wet-milled) or dry-processed (also called wild, natural or natural dry, and we abbreviate it DP sometimes). More, politics, age, Green coffee can be stored much longer than roasted coffee: Roasted coffee starts to lose its aromatics in 10 days after roasting. Green coffee can be stored months without degrading quality. Very often the type More, shipping conditions, diseases, etc.
To control the quality of your purchases, you must always get a representative green coffee bean sample for your own roasting and taste evaluation. What the broker tells you is secondary.
THE BROAD PICTURE
The more one knows about the history of coffee growth, species, processing methods, current events, trade information, etc., the better equipped one is to have insight into coffee buying. For example, with two broad statements, one can discount 2/3 of world production as not being suitable for “gourmet” quality coffees.
Namely, Brazils which are harsh non-aromatic, low yielding coffees, are of no interest. There are a few limited production Brazilian coffees that are excellent, but they are exceptions and in any case these are very difficult to obtain. Robustas are the other 1/3 of world production which beans have a Burnt flavors in coffee are the result of over-roasting, fast roasting, or roasting in a high-heat environment. This often occurs when the initial roaster temperature when the green coffee is introduced is too high. Usually, More A taste fault giving the coffee beans a highly pronounced burnt-rubber character. Result of continued enzyme activity in the coffee bean when it remains in the fruit and the fruit is allowed to dry on More taste, and usually wind up in the manufacture of instant coffees or are blended in substantial amounts in Hotel & Institutional coffees in the USA. Ironically, in France, the culinary nation, politics has dictated about 75% Robusta usually refers to Coffea Robusta, responsible for roughly 25% of the world's commercial coffee. Taxonomy of Robusta is debated: some sources use “Robusta” to refer to any variety of Coffea Canephora, and some use More use.
Of the 1/3 Suggests a harmony and proportion of qualities, and implies mildness since no one quality dominates.: Balance is both an obvious and slippery taste term. It implies a harmony and proportion of qualities, and perhaps a More of exports, are coffees referred to as mild . Most of these are “washed” beans, but some like Indonesians are available as a unique wet-hulled or dry-hulled (washed) coffees. Giling Basah is the name for the wet-hulling process in Bahasa language, and will have more body and often more of the "character" that More are naturally dried in the Either a flavor in the coffee, or referring to the fruit of the coffee tree, which somewhat resembles a red cherry.: Either a flavor in the coffee, or referring to the fruit of the coffee More. All these “milds” are not of the same quality. For example, Mexican coffees, have a characteristic taste that is not desirable, so that could discount 4 million (60 Kg) bags a year from the 1/3 world exports of 25 million bags. Half the milds grown in Central America, are not high grown, so that could be another 4 million bags of thinner quality beans. The rapid growth in the use of mechanical drying in Central America and elsewhere, as carried out, has a down-grading effect on coffee taste quality, and that can be another 4 million bags.
Processing damage can occur from the time the ripe cherry is picked until it is wet processed. For example, A key part of the wet process of coffee fruit is overnight fermentation, to break down the fruit (mucilage) layer that tenaciously clings to the coffee seed, so it can be washed off. Fermentation must More, rotting, mold growth, over-heating, improper storage and handling, droughts, excessive rains, diseases, pestilence, labor shortages, civil unrest, poor infrastructure (roads), excessive taxation, lack of capital, etc.
Often mechanical drying of the beans results in product quality inferior to patio drying. Many “beneficios” do not have complete nor up to date maintained machinery for removing defects, for bean size classification, for bean shape classification, cleaning out foreign matter, etc. Many “beneficios” do not have the silos and transport machinery to prepare 250 bag uniform lots. This is a most serious deficiency because, if all 250 bags are not uniform, how do you get a uniform sample?
If a “lot” of coffee beans (250 bags) is tainted with mold, As a defect flavor, a fruit quality in a coffee that is excessively ripe, toward rotten. Fermented flavor can be the result of poor wet-processing, over-ripe cherry, or some other contamination in the processing. As More taste, Rioiness, or foreign contamination, how much taint is there in each bag, each pound?
Labor wages are very low in the coffee growing countries, and often theft occurs by removing all or part of wholesome export quality beans from a bag and substituting reject coffee beans. The outer bag stenciling and appearance are normal, but the contents are not. Coffee beans have been known to be dyed green, because, that gives a better Refers to fresh shipments of green coffee within the first month or two of the earliest arrivals ... not quite the same as Current Crop, which means the most recent harvest. As a stable dried More appearance. Stones and foreign matter have been placed in green coffee bags, as good beans are stolen.
In many countries, notably Colombia, there is an astonishingly little amount of tasting done. Further, when tasting is done, it is done by people who have little understanding of what the consuming country buyer wants; reject low grade “dirty” tasting beans stay and are used in the growing countries, by the public.
Misrepresentation and theft are not just in the growing country, but occur in the consuming countries, e.g. green coffee brokers are often less than candid about what they are selling, and are prone to take advantage of the new roaster. Also there are strict sampling standards for 250 bag lots of coffee shipments, requiring taking samples from 10% of the bags at random, examining these samples relative to each other, and using the composite for sales samples. Needless to say this is hard drudge-like work, which is often not done properly or at all. The discovery of a non-uniform lot of bags, is a devastating situation for all concerned.
WHAT TO LOOK FOR
I feel most comfortable and safe with using “milds” from the traditionally sound producing countries whose general product is about 1 million bags/year or more, and to select their best. For example, a safe selection can be Colombian Supremos as opposed to Excelsos.
This does not mean that a problem won’t occur in such a selection, it only means that a problem is less likely. As good as Colombian coffee beans and bagged shipments can be in general, I personally have run into various deficiencies. For example, some shipments will taste better than others. Some shipments will have too many defects. When I asked the Colombian Federation management about this specific problem, they said they did not control the quality of what was exported by brokers. I’ve purchased coffee from Huila, and gotten beans from Medellin. The moistures on Colombian beans invariably run higher than from other countries, e.g. 13 to 14%.
I look for a green bean color. Jade color is ideal, but seldom obtained. A general characterization that cup flavors are diminishing in quality due to age of the green coffee, and loss of organic compounds. Before the use of inner lining barrier bags such as Grainpro or Ecotact, More green to gray colors mean that some deterioration has occurred in the shipment. A gray color means serious quality deterioration, e.g. over heated and prolonged storage.
A non-uniform bean appearance is an indication of poor preparation, and/or blending of different lots of beans. If this has occurred, it will reveal itself even more after the beans are roasted. Non-uniform bean sizes and shapes show a lackof proper preparation. Presence of many defects, definitely shows a coffee that has not been “benefacted”. Many black beans will give a “dirty” taste, resulting in a low grade coffee. Many white beans are not as bad as black beans, but white beans are defects that weaken flavor.
If I have traveled in the Country of Origin is where the coffee is grown in general terms. Region is a more specific area within the country. Arabica coffee grows in only in particular environments with adequate rainfall, temperate climates, good More of the beans purchased, I can sometimes relate conditions there with green bean product quality. An axiom worth remembering, is that if the country is having political, economic, or climatic problems, this will reveal itself in a lower grade quality of exports.
So, it pays to keep abreast of droughts, rain storms, revolutions, executions, oppressive administrations, excessive taxation, floods, volcano eruptions, and inflation.
Green coffee bean shipments from countries with large stocks, can often result in receipt of faded poor tasting lots.
When Colombia applies excessive export taxes, smuggling occurs. Although these could be “good” buys, there is always an element of risk in quality and quantity.
There are always “new” suppliers from the coffee growing countries with “good” deals. These buys are usually very risky . It is safer to deal with established importers who are on USA soil and with whom you can have recourse on any unsatisfactory purchases.
Smell the green beans. Examine their appearance for good green color, uniform size, shape & color. There should be no defects. Are the roast bean colors uniform? If not, that is an indication that the batch is non-uniform. The prevalence of lighter color beans after roasting means that immature beans are present. This results in a weaker, poorer and less uniform taste.
Always compare the freshly roasted sample to acomparable standard of your choice, e.g. last buy. Observe cup strength using the standard beverage preparation method. Some top quality beans can be 10 to 20% stronger than other good quality beans. On the other hand, poorer quality beans can be 20 to 30% weaker than other good quality beans.
The tasting should be done in aquiet, clean, pleasant environment free of distractions. It is essential to keep at least 1/4 lb. of the green bean sample until the actual bags arrive to confirm that the bagged coffee is the same as the sample furnished and taste tested.
WHAT REAL CUPPING IS
There is a tendency to believe that “cupping” is an isolated academic examination of the taste and Aroma refers to sensations perceived by the olfactory bulb and conveyed to the brain; whether through the nose or "retro-nasally": The aromatics of a coffee greatly influence its flavor profile and come from the perception More of green or roast coffee samples. In general it is “THE TEST” that helps one make the decision to buy or not to buy an offering. In the case where there is a production problem, taste testing can often pin point the start/end and scope of a taste variation, associated either with the raw commodity or with the processing of that commodity.
Therefore taste-testing encompasses a personal capability of tasting sensitivity combined with other technical knowledge about the coffee’s processing conditions. For example, one might be able to discriminate between the material and the process as the source of variation The ability to discriminate can translate either into solving a quality variation problem and/or upgrading the quality of the finished product.
Since there are many types of coffees, and even more modes of preparation, the ability to see into these circumstances becomes a valuable skill acquired over time.
The point is that “CUPPING” abilities and skills are largely related to real life circumstances. Each experience punctuates our memory about that “problem” with that taste.
I shall attempt to illustrate this with several examples:
- Rioy Taste
: As a consultant to a major hotel chain, on evaluating their varied sources of coffees, I discovered that one hotel was using an objectionable tasting R&G coffee with Medicine-like, alcohol or chemical type flavor taint.: A defective flavor characterized by a penetrating medicine-like, alcohol or chemical type taint flavor. This type of defect usually comes from poor processing or storage, but could indicate More taste. The specific supplier/green coffee buyer refused to discuss the nature of his blend and would not admit to using “RIOY” beans. They lost the major hotel account.
- Acid Tasting Coffees
: A Kenya bean was offered for sale. It was not typical, and was very acid even at a dark roast. Having examined many types of coffees in a pH beverage study, I knew that this was abnormal. We do not buy abnormal tasting coffee beans.
- Misrepresentation of Sample
: A sample may not represent the bag contents, either because the broker deliberately sent a “better” sample than the shipment, or the 250 bag lot was not uniform. We have encountered both circumstances from several brokers.
- Moldy Taste
: We received a preliminary Sumatra sample. I found it had a small, but definite, moldy taste. When I rejected this proposed purchase, then only did the broker agree that indeed it did have a moldy taste. Otherwise I would have had 20 moldy bags of coffee.
- Flat Taste
: I had been buying on a repeated basis, Kona coffee beans at $5/lb + transportation. A new shipment arrived that was not consistent with the previous shipments; it was flat. I immediately inquired with the Kona supplier. In this case he was honest and admitted to having the “beneficio” over-heat the beans during de-husking/polishing.
- Weakening Taste
: We bought some fine quality Tanzanian beans, however, we observed over a two month period, that the taste was weakening and the bean color was fading from a fair green to a very pale. Our storage conditions were the same for all our beans, others of which did not fade. Since then we have discovered that improperly prepared green coffee beans, will have a weakening taste.
- Caramelized Taste
: This pertains to the processing of the green bean. In brew from R&G coffee held too hot or too long on a warmer or overheated extracts in instant coffee processing.
- Ateng is a common name for Catimor coffees widely planted in Sumatra and other Indonesia isles.: Ateng, with several subtypes, is a common name for Catimor coffees widely planted in Sumatra and other Indonesia isles. More Taste
: A customer tells his roaster supplier that he wants more creme (foam) on his A small coffee beverage, about 20 ml, prepared on an espresso machine where pressurized hot water extracted through compressed coffee.: In its most stripped-down, basic form, this is a working definition for espresso: A small More drinks. He furnishes a competitor’s sample of R&G coffee. You taste it, and recognize a definite strong burnt rubber/bitey objectionable taste. Said sample has perhaps 33% Robusta in blend.
Getting started is hard. But nature has given each of us an exceptionally sensitive nose andtongue, wherein we can taste minute as well as gross differences in our coffee beverages.
ANECDOTAL RELATIONS of TASTE to CIRCUMSTANCES
- Beverage Preparations
: It had become impossible to compare various coffee samples because of differences in roasting, grinding, weighing, and water temperature. Comparisons must be made with consistency in the preparations, since variations to the routine can show considerable differences in cup strength.
- Cup Strengths
: What was attributed to be a SHG (A classification used in some countries in Central America, indicating the coffee was grown at an altitude above 1200 feet/4000 meters. Beans grown at a higher altitude, have a greater density, and thus a better More) central American bean, when cupped against a reference of known integrity, showed that the sample was noticeably weaker. This could have been because the bean was not SHG, but came from an elevation of 1,500 feet, and/or the bean was washed excessively causing it to lose most of its solubles.
- Dirty Taste
: This taste is usually associated with samples containing large amounts of black beans (e.g. 1 wt. %) It can also occur in green coffee samples that appear to be clean, uniform, and with few defects. This is not an acceptable taste.
- Fermented Taste
: From 20 bags of coffee received, there were varied levels and types of fermentation. A small amount of fermented taste can be sometimes desirable, however, the danger is whether all 20 bags are uniform. Since a fermented bean is an isolated contributor, it is unlikely that the same level and type of fermented taste will occur in every bag.
- Broker Misrepresentation
: I purchased some Sumatra for my shop. The broker sent me a #6 grade, loaded with defects, which he claimed fervently was a #1 grade. I have not bought a bean from this broker since.
- Roaster Operator- Not following Instructions
: A new roaster operator complained to us that his roasted beans had lost favor with his prior customers. I roasted his green beans and the resulting beverage was excellent, but the beverage from his beans was not. It turned out that he was not cooling the roasted beans upon discharge from the roast chamber. This variance in roasting procedures caused the difference in taste.
- Panamanian Coffee
: Located just south of the Costa Rican border at near 5,000 feet, Boquete, grows and exports green beans. These can be very good or very bad, and it is risky to buy them, although tempting. A major problem is that as a small area producer, they don’t have the proper equipment for classification or grading and silo preparation of 250 bag lots. The procedure is to pile the green beans on the concrete patio, and have six men manually shovel that pile into another pile, thereby effecting some mixing. This kind of mixing is not very good, especially when the bean lots mixed are not equal quality. The net result is that no sample from any one bag is representative of the whole. Detailed examination of the beans from each bag revealed wide variation in defects and was non uniform in color after roasting.
- A flavor descriptor in coffee reminiscent of herbs, usually meaning aromatic, savory, leafy dried herbs. Usually, more specific descriptions are given, whether is is a floral herb, or sage-like, etc. In reality, there are very More Kenya
: After receiving 18 bags of Kenya, we noticed an herbal odor. Before paying for the beans or transport, I sampled and taste-tested the shipment. No herbal taste was present in these beverages. Upon investigation, we discovered that the trucker had a warehouse occupied by spices and herbs. The dust had settled on the bags of Kenya coffee. We were relieved, but spent a good deal of time and worry until this matter was investigated and found to be non-threatening.
- Contract Purchases of Green Beans
: Normally, I buy beans based on samples furnished, and not by contract, as many brokers like to do. One San Francisco broker refused to write in contract that the beans would have “NO” defects or not more than 4 defects per 300 grams. When the coffee arrived, it had 22 defects per 300 grams. Upon presentation of this disparity, the broker said he would rebate for the deficiency. However, he did not, and I never purchased beans from him again.
- Past Crops
: Most brokers offer beans, and the buyer assumes (often wrongly) that this is a new crop. Past crops can be one, two, or more years old. The beans are no longer green, but gray. The taste of past crops can be satisfactory or progressively lacking in aroma as the years go by, depending on conditions of storage. It is important to have the broker-seller commit to when the crop was harvested. Older coffees not only have poor aroma, but can also lose Associated with and sensed by mouthfeel, body is sense of weight and thickness of the brew, caused by the percentage of soluble solids in the cup, including all organic compounds that are extracted from brewing More, flavor and character.
TASTE TESTING PROCEDURES: Traditional Green Coffee Broker vs. Gourmet Roaster
Traditional green coffee seller/buyer beverage preparations leave a great deal to be desired relativeto gourmet coffee consumer preparations.
It is my opinion and practice, to not use the techniques of the traditional green bean buyer, for several reasons:
- The sample drum roasters used are too expensive and take too long to roast. They do not bring out the most and best flavors from the beans being examined. For example, a 4 barrel gas or electrically heated bank of sample roasters installed can cost US$ 10,000.00, whereas a heat gun spouting bed roaster can cost $80.00. The later takes 2.5 minutes to roast 30 grams of green beans which is enough to make 3 cups of coffee.
- The traditional evaluation roast uses a light roast (perhaps 14 wt % loss). This is so light and short of optimum flavor development and the flavors developed are not what the consumer uses. Light roasts are believed to be used to highlight off-tastes. In my opinion “OFF” tastes can also be readily observed at 15 to 16 wt. % losses, which is close to degrees of roast used commercially today in gourmet operations. The lighter roasts may have been more comparable to 50 years ago when canned coffees were made with less weight losses, and less consideration of what is a properly developed Flavor Profile implies a graphical impression of a particular coffee, whether it be an artistic portrait or data graph of the perception of flavor compounds. In the case of our spider graph charts in each More.
- The traditional evaluator also used a relatively coarse grind , “regular,” certainly coarser than drip, more equivalent to the grind of canned coffees in the USA 50 years ago. Such coarse grinds produce a weak insipid drink, whose taste profile is unnatural to what is going on in the market place today.
- The coarse granulation and light roast produces granules that are not readily wetted, hence they float and are under-extracted. These form a barrier to the taster trying to evaluate the beverage. The taster has to skim off the floating granules, which is usually a messy procedure and often incomplete. The presence of grounds interferes with the taster’s ability to accurately evaluate the coffee beverage.
GOURMET COFFEE TASTING PROCEDURES
Today in the 1990’s we have a broader selection of beans, degrees of roasts, fineness of grinds and cultural uses than ever before. We are not limited to the canned, stale, lightly roasted, or coarsely ground commercial coffees.
- We use the heat gun spouting roaster that takes 2.5 minutes for 30 grams of green beans.
- We use a middle European roast with a 15 to 16 wt. % loss and optimum flavor development. The once thru A fluid-bed roaster works by pushing hot air across coffee beans. Fluid-bed roasters are generally less expensive than comparable drum roasters, and they produce a bright flavor profile.: A fluid-bed roaster works by pushing hot More does not deposit Grown without the use of artificial fertilizers, herbicides, etc.: Organic coffee has been grown according to organic farming techniques, typically without the use of artificial fertilizers. Some farms have more local Organic Certification than the More tars on the beans. These tars are an obstruction to proper evaluation of the basic tastes derived from the green beans.
- We use a “fine” grind, almost espresso grind, so that wetting and Refers to the process of infusing coffee with hot water. Hot water releases or "extracts" the flavor from the roasted, ground coffee. The term is used mostly with espresso, adding pressure to the mix as More are quick and thorough. We separate the spent grounds from the beverage with a fine mesh Nylon strainer or “gold” strainer. There are no floating coarse grounds to “break” & wipe off.
- This rapid procedure, consistent with today’s coffee consumption, is more economical, quicker, and closer to what gourmet consumers are consuming
TASTING & THE CHEMISTRY OF COFFEE AROMAS & FLAVORS
With the growth of coffee retailing and roasting, those who do not have a chemical education, in regards to coffee, will find it difficult to appreciate the chemistry of roasting, the chemical compositions of aromas, and the chemical and physical changes and contents of the bean, grounds and beverages.
I will simply illustrate this point as follows:
In 1956, when gas chromatic analysis was in its infancy, I contracted Professor Zlatkis of the University of Houston to do analyses of the coffee aromas we were collecting at the Folger roasting and instant plant in Houston. We were exposed to one of the marvels of a science that was only beginning.
We took the condensed aromas from ice water traps, dry ice traps (-760C), and liquid nitrogen traps (-273 0 C), for gas chromatic analysis. In such analyses, an absorbent column slowly releases the individual components of aroma as an inert purge gas passes over the absorbent.
By smelling each component as it was purged, we could appreciate its contribution to the overall aroma of coffee. Many of these components were very volatile and unstable, so the elapsed time overall was critical to getting a genuine impression. We could smell acet-aldehyde, acetone, ethyl-ester, propyl-aldehyde, diacetal, Acetic acid can lead to vinegar-like flavors in over-mature coffees, or bitterness in high quantities. But in moderate amounts it adds a positive winey note to the cup. Acetic acid classifies as an organic acid, More, etc. Many of these mentioned represented large percentages of the aroma. However, their sensing threshold concentrations were relatively high. There were other aromatics which were much more potent to our senses, a thousand fold, e.g. di-methyl sulfide.
We not only confirmed these chemicals by smell but also by mass spectroscopy , which combined with gas chromatography formed a very sophisticated analytical procedure. Subsequently other investigators at the SW Research Institute in San Antonio, Texas, the QMC research laboratories in Massachusetts, and by the Tenco Division of Coca Cola Corporation. expanded these studies and reported around 100 major chemicals and around 300 minor chemicals in the coffee aroma. Needless to say the range of concentrations found on the numerous individual chemicals varied with green bean type, source, processing as green, processing to roasted, Degree of Roast simply means the roast level of a coffee, how dark it has been roasted.: Degree of Roast simply means the roast level of a coffee, how dark it has been roasted. The More, etc. As chemists who recognize many of these components individually, it was very educational and impressive to relate and identify each in the The co-presence of many aroma and flavor attributes, with multiple layers. A general impression of a coffee, similar to judgments such as "balanced" or "structured" More mixtures evolved.
To this extent a chemist, chemical engineer, or food technologist, is better able to see the chemical compositions that make up coffee aroma
Also related to this, was a program in the 1950’s and early 60’s to aromatize instant coffees. I had the opportunity to add back many of these components to coffee extracts and powders and had personal taste experiences with upgradings made with diacetyl (butter-like), An important factor in coffee aromatics, partially formed in roasting by the interaction of fatty acids and oxygen: Along with Ketones, Aldehydes are an important factor in coffee aromatics, partially formed in roasting by the More, An ester is an often fragrant organic or partially organic compound formed by the reaction between an acid (including amino acids) and an alcohol. They play a smaller role in coffee aromatics than Ketones and More, sulfides, etc. We could taste these components and their contributions to the coffee, and the concentrations required for positive taste benefits. This was exciting applied science.
The green coffee bean buyers worked on an empirical tasting program tied to low priced canned coffees, and even then resented the intrusion of scientific method as applied by chemists, engineers and food technologists.
Lingle, Ted, SCAA Coffee Cupper’s Handbook & Basics of Cupping Coffee 1990
Elkin, M., SCAA Cupping 100, Houston, Texas, 1994
Sivetz, M., AVI Coffee Technology & Coffee , Origin & Use, 1979
Sivetz, M., Coffee Quality, 1995
Food Technology, V26 No. 5 p70-77, Acidity is a positive flavor attribute in coffee, also referred to as brightness or liveliness. It adds a brilliance to the cup, whereas low acid coffees can seem flat. Acidity can sound unattractive. People may More & The overall impression in the mouth, including the origin character as well as tastes that come from the roast.: This is the overall impression in the mouth, including the above ratings as well as tastes More, 1972
SIVETZ CHECK LIST ON COFFEE BEAN PREPARATIONS FOR TASTE EVALUATIONS
- Sample Roasters:
- 1 Kw Heat Gun: 30 gram, 2.5 min, $100; 70 gram, 5 min, $165
- 1.2 Kw Modified Corn Popper: 1/4 lb. in 5 min., $185
- 8″D Brass screen to inspect roasted beans.
- In tray, green coffee bean evaluations-preliminary.
- Color, odor, size & shapes and general appearance in uniformity.
- Odors and amount of popping sounds during roasting.
- Visual examination of roasted beans, colors, sizes & shapes.
- Fine Grind:, uniform granulation. Smell freshly ground coffee.
- Proportion of R&G coffee to near boiling water. 10 grams/200 ml.
- Separation of spent grounds from beverage (fast). We use and prefer a Nylon 60 mesh screen. Steeping time 10 sec.
- Number of cups evaluated at a time. Five maximum. Use top quality white porcelain cups of 6 fl oz capacity.
- Water must be free of chlorine and excessive alkalinity or solubles. The water must be a joy to drink in itself.
- Timing in Preparation of beverage samples: To be done by others (trusted), as quickly as possible for uniform temp.
- Use silver or silver plated spoon, your personal one, for tasting only.
- Tasting Environment: Quiet, undisturbed atmosphere, with clean utensils and air, to allow for concentration and reflection. No phones, no messages, no distracting conversations.
- Slurping & Spitting out samples: Do not swallow the coffee beverage. You may even have to rinse your mouth out with tepid water between tastes. In extreme cases, you may have to eat a saltine cracker to eliminate the last taste.
- Spitting Bowl: To minimize the social abhorrence of spitting out the coffee beverage, a dentists’ water whirling bowl is recommended, or water running in a sink with periodic water spray wash down. I personally find the use of a spittoon today unacceptable, and objectionable.
- Documenting Taste Impressions: Write down your taste impressions of each cup both at initial tasting temperatures of 125 to 130 degrees F, and then again at 100 degrees F. Frequently tasting at both temperatures is better and more instructive.
- Taste Communications: Compare your own taste impressions with one or two other skilled tasters to confirm your reactions collectively from the “same cup.” Such discussions after all have tasted are often very helpful in decisions.
LEARNING TO TASTE
One of the greatest apprehensions a person has, when considering entering the coffee business, is the anticipated training and education required for tasting different origins and different defects in coffees.
Fortunately, most people have the natural facilities for smelling and tasting, and it is simply orientation and experience that are required.
Most coffee “cuppers” and buyers have learned their skills under the tutelage of a senior person in a large coffee company.
Knowledge of tasting terminology makes it possible to effectively communicate with exporters, brokers, peers, and customers. COFFEE TASTING has a language all its own. It is not very difficult, but it encompasses a breadth and depth of experience that cannot be learned overnight.
Without a grasp of this language and education, one can become a victim of the green coffee bean seller or broker, because it is difficult to convey the short comings of the offering. Learning the trade accepted taste terminology also helps one communicate more effectively with employees.
It is important to taste beverages on the same turn table with an expert in order to have the opportunity to discuss the source and cause of tastes identified. There are tastes, for example, like Bitterness is one of 5 basic tastes: Sour, Sweet, Salty, Bitter and Umami (savory flavors). There are many types of bitterness, hence not one avenue to tracking down its source. Bitterness as a positive quality More which taste acid to some, and one must be aware of such genuine taste impressions.
Another obstacle to learning coffee tastes is the secrecy that many coffee buyers hold on this subject, since it constitutes their livelihood. They do not want to create competitors for their job, nor do they want to share the details of their taste decisions. The buyer may be buying marginal quality green coffee beans and is not willing to share this information or to discuss his taste impressions on decisions to buy.
When you hear of taste tests with coffee carried out by lay or general public, you can be sure that you are asking a tongue uneducated group for opinions. The results are usually strange, if not erroneous. The tasters cannot communicate properly .and the scope of their knowledge is small.
You will find casual terminology in flyers published by sellers of roast coffee to the Gourmet Trade. For example, the following terms have been taken from 25 word descriptions in the Superior Dowe Egbert flyer; and they are not meaningful or used in professional green coffee buying & tasting:
- A general primary-to-secondary post gustatory flavor characterization, often called "rich" or alternately "smooth" Coffee that has been hanging out in the warehouse, but not really helping out with the work, just relaxing over in the More
- A flavor or mouthfeel characteristic, hinting at a tingly, prickly, lively or piquant aspect. Peppers, spice or citrus can all be zesty. More
- An adjective modifying a flavor descriptor, describing a sharp effect; tangy citrus, tangy bittersweet flavor, tangy green apple. More
- Creamy is a mouthfeel description indicating thickness and soft, rounded texture. See also buttery. More
These words are usually created by advertisers.
The Professional terminology following was taken from Coffee Technology 1979 Table 15.1:
- A general negative flavor term, from defect bean, bad roast, or bad brewing: Unpleasantly sharp, astringent or bitter to the taste or smell More
- Astringency is a harsh flavor sensation, acrid flavor, that provokes a physical reaction on the toungue, the tactile feeling of papery dryness. It can have saltiness, sourness and bitterness as components. It is certainly the More
- A mouthfeel description indicating thickness and creaminess, and can also be a flavor description.: Buttery is primarily a mouthfeel description indicating thickness and creaminess. It indicates a high level of lipids (fats) in the coffee, More
- Earthy is a flavor term with some ambivalence, used positively in some cases, negatively in others.: Sumatra coffees can have a positive earthy flavor, sometimes described as "wet earth" or "humus" or "forest" flavors. But More
- Greenish flavor in the cup, usually indicating early crop, unrested coffee.: Greenish flavor in the cup, usually indicating early crop, unrested coffee. This is a fresh cut grass flavor, chlorophyll-like, not a dried grass or More
- Heat Treated
- Hay Like (Furfural)
- Egg Like (Hydrogen Sulfide)
- Off aroma and flavor that reminds one of a dank, moldy closet. This flavor can hint at a dangerous coffee mold and should not be consumed.: Off aroma and flavor that reminds one of a More
- Natural (Unwashed Beans)
- New Crop
- Old Crop
- Pyridine (Obnoxious Easily Recognizable Chemical)
- Refers to an aggressive, intense aroma or flavor, often related to spices (pepper) or roast tastes. Pungent foods are often called "spicy", meaning a sharp or biting character, but not unpleasant. Bittersweet tangy roast flavors More
- Nutty is a broad flavor term, reminiscent of nuts ... but what kind exactly?: Nutty is a broad flavor term, reminiscent of nuts. It is tied intrinsically to roast taste and the degree of roast, More
- Sour is one of four basic sapid (in the mouth) tastes: Sour, Sweet, Salty, Bitter (and possibly a 5th called Umami which indicates savory flavors). In coffee, sourness in moderate amounts of favorable, although the More
- A taste term to describe a wine-like flavor with a similar perceived acidity and fruit, and some level of acetic acid. It is found most commonly in East African specialty coffees as well as in More
- Generally a taste defect from age; old green coffee, perhaps yellowing in color. This is due to the drying out of the coffee over time, and as the moisture leaves the seed it takes organic More
It is important to note that persons who are trained in chemistry and have had the opportunity to smell unique chemical odors, have an advantage in identifying characteristic odors coming from coffee.
Gas chromatographic releases of individual chemical compounds and odors make it possible to speak of acet-aldehyde pungency, or acetic acid, di-acetyl (buttery), methyl mercaptan (potent), buty-ric acid, etc.
The usual coffee buyer does not know his chemistry, and hence does not appreciate these odor sensations.
INSPECT GREEN BEANS
When receiving a green coffee bean sample from a broker, it is necessary to visually inspect the spread of beans for color, color variation, bean size, bean shapes, and general uniformity. Smell the green beans to determine if there are any “off” odors, like mold, As an aroma or flavor in coffee, ferment is a defect taste, resulting from bad processing or other factors. Ferment is the sour, often vinegar-like, that results from several possible problems. It might be the More, or foreign contaminants. Note the number and type of defects refer to the grading chart. If there are many defects, sort out the defects and weigh for wt% content. One may sort out all the black defects to see what effect this has on taste (often notable). Roast a 2 ounce (70 gram) sample. Note odors during roast and uniformity of color developed. If roast color is not uniform, the beans are not uniform. Note “popping” sounds while roasting as index of bean quality.