Coffee roasting and Coffee Flavor Wheel New version of Coffee Flavor Wheel

counterculture coffee flavor wheel

Deep-baked highlight wood incense

Light baking can highlight the bright smell of flowers, grass and fruits, but the deep baking fans who have no medicine can fall in love with the incense, stuffy fragrance, choking fragrance and alcohol of resin components. This is the product of Mena reaction and dry distillation. (Resin component: Pine and cedar families of conifers, all secreting oleoresin compounds, with an acrid fragrance to resist pests or squirrel nibbling)"Dry distillation" refers to the isolation of air by solids or organic substances, dry burning to complete carbonization, and the isolation of air is intended to prevent oxygen combustion or explosion.

Taking wood chips wrapped in tin foil paper for dry distillation as an example, charcoal can be produced and coke products such as formaldehyde, acetic acid, tar and gas can be generated. Although coffee roasting is carried out in a semi-enclosed drum or metal tank, oxygen can still enter and exit, it seems that it is not like the oxygen-free smoldering environment of dry distillation, but under normal roasting conditions, coffee beans cannot be roasted to complete carbonization combustion, so the dehydration, pyrolysis, dehydrogenation and coking experienced by the beans before combustion are almost the same as dry distillation, and the medium roasted beans will also generate a lot of burnt or pungent odor components. Thus the deep aroma can be attributed to dry distillation.

The aroma of light baking and medium baking belongs to low and medium molecular weight, but after entering the deep baking world after the second explosion, carbonization intensifies, caramelization disappears, but Mena reaction continues, amino acids and polysaccharide fibers are continuously explained and polymerized, producing more high molecular weight binding compounds. The interpretation of aroma is dominated by Mena reaction and dry distillation reaction from caramel conversion, mainly with burnt aroma and stuffy aroma.

As the saying goes,"One man's meat is another man's poison." The "aroma spectrum" of dry distillation is divided into three categories: resin rhyme, spicy rhyme and carbonized rhyme, as follows:

1. Resin Rhyme: Turpentine and Choke

Turpentine: turpentine, chicory, myrtle, alcohol, blackcurrant branches

Choke flavor: rosemary, eucalyptol, eucalyptus leaves, camphor

2. Spicy Fragrance: Warm and Aromatic

Warm: fir, cedar, celery seed, pepper, nutmeg

Aroma: Cinnamon, clove, laurel leaf, bitter apricot, thyme, pepper

3. Carbonization Rhyme: Choke and Ash

Smoke: tar, tar, tires, tobacco

Ash smell: charred, coke

Pine cedar aroma with mixed reviews

Flavor wheel will turpentine incense and koala favorite eucalyptus leaves, such as spicy choking smell, classified as dry distillation of the aroma. However, this kind of spicy flavor is not the patent of deep baking, and it often appears in the middle baking that has not yet entered the second explosion.

The most recent U.S. Cup boundaries are Nariño, Huila's "Extraordinary Cup" winning coffee from southern Colombia, and El Salvador's national treasure, the Parcamara.(Pacamara), Hawaiian Kona and Mantenin, sometimes with rosin (Piney), and Honduras famous garden beans also have eucalyptus tree aroma, puzzled, after heated discussion, the final conclusion is that these coffee plantations coincidentally, are planted with pine, fir or eucalyptus leaves, which may be the source of pine cedar aroma. But there are still experts who do not believe that pine, fir, camphor or eucalyptus trees are planted near coffee trees, and the spicy ingredients will be absorbed by coffee seeds, and after roasting, they will actually become volatile aromas that can be smelled by the nose. I have to say that this adds a little surprise to romantic coffee.

Should turpentine be awarded points or deducted points? There are also different views in the trade. Some people think turpentine is a disgusting smell, while others think that pine incense can add layers. To be fair, coffee's elegant pine cedar aroma is not bad as long as it does not choke the nose. To know that coffee beans themselves are hard fiber, how much will have wood flavor or pulp flavor, Brazil flat commodity beans have this problem, on the other hand, more than 1500 high-quality Arabica beans, after brewing, send out light warm furniture pine cedar fragrance, better than rotten rotten wood flavor.

As for the annoying carbonized smoke of deep-baked beans, most of them are caused by the accumulation of carbonized particles in silver skin or fiber, and the other part comes from volatile heterocyclic compounds and phenolic compounds with high molecular weight. Therefore, the rosin aroma created by dry distillation. Spicy fragrance and carbonized smell, as long as the burning smell is effectively controlled, and then highlight the elegant rosin, snow fir fragrance, and even turpentine slightly alcohol, should be applauded.

Cellulose is the source of all fragrance

The above is the "smell spectrum" of dry distillation and Mena reaction after roasting into the second explosion. It seems quite scary, and it has turpentine fragrance and carbonized taste. However, the medium and deep roasting after the second explosion is the most acceptable roasting degree for the general public because of its low acidity. It is especially obvious in the south of Taiwan. The sour aroma of light and medium roasting is not popular in the coffee market in the south, which is afraid of bitterness.

This year, Europe and the United States blew the "third wave" cyclone of fine coffee, mainly from lighter medium roast to medium deep roast, and rarely roasted to the second explosion.(Agtrron #30 ~40) or the end of the second explosion (Agtrron #20 ~30) re-roasted, but the roasting degree of the second explosion is more than ten years ago, the characteristics of the "second wave" of fine coffee, bean surface oil bright, good technology, not only not bitter, but also exudes the sweet taste of alcohol and turpentine, similar to banana oil (isoamyl acetate), turpentine, cedar or nutmeg, and like the warm aroma of home pine furniture, every winter, a cup in hand, warm heart.

Catte d'arte, a famous coffee in Seattle, USA, is typical of this aroma. The espresso extracted will have alcohol and cedar aromas, which is very attractive.

Recently, scientists have discovered that the rich aroma of medium and deep roast coffee does not come from caramelization of sucrose, but from the polysaccharide cellulose of the thick cell wall structure of raw beans, which is the breeding ground for Mercaptan compounds (Mercaptan compounds), which are the main source of aroma and alcohol emitted by ripe beans.

"Thiols" create a deep baking aroma

Since Reichstein and Stoddinger, two Nobel laureates, reported in 1962 that furans, thiols and alkyl pyrazines. Diketones are the key to coffee aroma. In fact, scientists have made great progress in this area for many years. The world-famous Kraft Foods Company (Kraft Foods) Chemist Thomas Palleman Thomas H Parliment and Hall Stout Howard D.Stahl and Oxford Chemical Company (Oxford Chenicals) David * Rowe (David Rowe) and other scholars research report, all pointed out that the fascinating aroma of coffee, whether light roast, medium roast or heavy roast, as long as it comes from thiol compounds, that is, thiol (Mercaptan or Thiol) and "furan","ethanol","ketone" or "aldehyde" derived aroma compounds.

However, coffee does not contain such compounds, thiol compounds are the products of fire refining, will increase with the depth of roasting, the formation of thiol compounds is exactly the opposite of the acid fragrance of fear of fire, the thiol concentration of deep roasting is significantly higher than that of shallow medium roasting, which is why the ripe beans entering the second explosion will be more fragrant and attractive than the coffee before the end of the first explosion, and more acceptable to the general public.

When coffee bags are opened or ground, an intoxicating aroma wafts out, mainly from thiols, as a criterion for determining whether coffee meets the freshness criteria.

Thiol origin revealed

According to Palleman and Stout's study in Coffee Aroma Chemistry, the precursors of thiol compounds, Arabinogalactan and cysteine, are stored in cellulose and lignin in the thick cell wall of coffee beans.

Furfuruyl, one of the raw materials for synthesis of thiol compounds, is the degradation product of arabinogalactan. The second original "sulfur" of thiol compounds comes from the pyrolysis products of "cysteine". In other words. Thiol compounds are cellulose in the cell wall of coffee beans. Lignin and amino acid degradation and polymerization of aromatic products, to put it bluntly or sugar and amino acid Mena reaction credit, thiolate can also be said to be "furan" and "aldehyde ketone" and "sulfur" polymer.

Most people see the word "sulfur" will associate sulfur and rotten eggs bad taste, but sulfur and furan and aldehyde ketone combination, will create a charming aroma, this is the coffee aroma of the top secret.

The Sulphur Compounds in Foods, published by Palleman and Stout in the American Chemical Society, indicates that thiols increase with coffee roasting, with gas chromatography measurements showing that very light roast coffee (Agtrron #95) has less than 10,000 thiol units, medium roast coffee (Agtrron #55) has a sharp increase in thiols to 50,000 units, and deep roast coffee (Agtrron #32) has a thiol level of 70,000 units.

Thiols produced from carbohydrates and cysteine in laboratory require higher energy to produce, which coincides with the fact that thiols are much higher in medium and deep baking than in light and medium baking, indicating that thiols require higher energy to produce.

Thiols have chocolate, butterscotch, cocoa, banana, egg, and even meaty aromas. They are the aroma of light, medium, and dark roast coffee. In addition, there are three compounds closely related to coffee aroma, including "4-ethylguaiacol"(4-ethylguaiacol),"Alkylpyrazines"(Alkylpyrazines) and "Isopentenyl mercaptan" Three are also related to (Prenyl mercaptan) coffee thick cell wall, coffee beans cellulose accounts for 40% of the bean weight, which makes coffee cell wall structure is much harder and thicker than other seeds.

Pellerman and Stout in Why Coffee Smells So Good (WhatMake That Coffee Smell So Good?) Previous studies have shown that precursors of thiol compounds may be hidden in coffee's thick, hard cell walls, a finding that provides part of the answer to the question of why coffee is more mellow and attractive than other bell seeds or beans.

Deep bake. Don't try.

The beans, black beans, cashew nuts, sweet apricots and pumpkin seeds were roasted in a roaster. The beans and nuts were soft in texture and could not withstand heat. Although they also had aroma, they were far from coffee. In the past, coffee chemists have focused on the sucrose, fat, protein, trigonelline and other precursors of coffee aroma, but in recent years, they have turned to the long-neglected structure of coffee cell walls and polysaccharides. How to improve the cell wall thickness of coffee through post-processing of biochemical and planting technology, and then improve the flavor after roasting, will be an important issue.

Although the above research points out that thiols increase with the degree of roasting, but do not misinterpret it as the more fragrant coffee is roasted, it should be known that roasting is a very complex degradation and polymerization reaction of thousands of compounds, although thiols increase with the degree of roasting, but the accumulation of "carbonized coke particles" and "green acid" The bitter degradation products also increase rapidly, it is easy to cover or offset the aroma of thiols, without its advantage.

If the deep baking or rebaking technology is not skilled, do not try, it is best to use the early or middle of the second explosion dense explosion quickly out of the furnace, so as not to lose, because the ability to control the carbonization of the second explosion tail and the scorch taste to the lowest baking master, very rare.