How to: Espresso Roasting and Grinding

If you’re a coffee lover then you’ve come to the right blog at CM Roasters. We hope that you enjoy our tips and tricks to not only buy the best coffee, but grind and roast your coffee beans at home as good as any barista!

Sit back with your favorite cuppa and enjoy!

Coffee Roasting

After quality coffee beans are obtained, the most important phase of the production of gourmet coffee begins, the roasting and the blending.

A good roaster must be part artist, and part scientist, to maintain quality and consistency. It is during the roasting process that the sugars and other carbohydrates within the bean become caramelized, creating a substance which is known as the coffee oil. Technically, this fragile chemical is not actually an oil (since it is water soluble), but it is what gives the coffee its flavor and aroma.

Specialty coffees are generally roasted in small batches. The two most common roasting methods are: drum-roasting and hot-air roasting. Drum-type roasting machines roast the coffee beans as they tumble in a rotating drum that is typically heated by gas or wood. When the desired roast is achieved, the beans are poured into a cooling hopper to keep them from overcooking. The hot-air roaster, also known as a fluid-bed roaster, roasts the coffee beans as they tumble on a current of hot air.

Most green coffee is roasted at approximately 400 degrees. The roasting process causes the coffee beans to swell and increase in size by over 50%, while at the same time greatly reducing their weight.

A lightly roasted bean may range in color from cinnamon to a light chocolate tan. Lighter roasts are generally not used for espresso since they produce a sharper, more acidic taste than do darker roasts. Darker roasts, in contrast, have a fuller flavor approaching a bittersweet tang. The amount of oil drawn to the surface of the bean increases proportionately to the length of roasting time.

As the roast darkens, caffeine and acidity decrease proportionately. Dark roasts can range in color from a medium chocolate brown with a satin-like luster, to an almost black bean with an oily appearance. The darker the roast the more you will taste the char, rather than the flavor of the bean.

Extreme dark roasts will tend to have a smoky flavor, and are better suited for brewed coffee rather than espresso.

Many roasters refer to the following terms concerning the degree of roast, from light to dark: Cinnamon, Medium High, City, Full City, French, and finally, Espresso or Italian roast. On the West coast of the U.S., French roast is the term generally used to describe the darkest roast. It is important for you to understand that these terms have no relationship to where the coffee is grown or roasted.

With more than 100 coffee-growing regions in the world, each producing beans with distinctive characteristics, we believe proper blending is essential to the balance of flavors necessary to create superior espresso. A single coffee bean will generally not possess the complexity necessary for great espresso. Many espresso blends will contain three to seven different types of beans.

The experienced roaster, with his knowledge of each bean, artfully combines them to create the desired blend of flavors. The roaster’s blending knowledge is usually a closely guarded secret.

In the United States, 100% Arabica beans are generally used for gourmet espresso blends. As we mentioned earlier, in Italy, some robusta beans will often times be added for the additional crema, caffeine, and complexity they contribute to the blend. The Italians possess generations of expertise in the art of blending coffees for espresso.

Argument still exists among roasters as to which should occur first, the roasting or the blending. Generally, roasting each varietal separately to maximize its flavor characteristics, and then blending, will produce the best result.

Freshly roasted beans will release hundreds of chemical substances in the form of vapors. A day or two will generally be required for these gases to dissipate before the beans will reveal their optimal flavor characteristics.

Coffee Grinding

  • It is best to grind your coffee as you need it. Once the beans are ground, the flavorful oils are exposed to the damaging air. As these oils dissipate, so will the flavor of your coffee. Once ground, coffee will begin to lose its flavor almost immediately.
  • The best way to grind coffee is with a mill or burr grinder. Avoid the cheap blade grinders as they simply cut your coffee creating unequal and un-uniform pieces that will not brew properly.
  • For Drip Coffee Makers – If you use an automatic drip coffee maker, grind your beans to the consistency of granulated sugar. The complete drip cycle should last for four to six minutes. If the drip cycle takes less than four minutes, grind your coffee finer. If it takes longer than six minutes, grind your coffee coarser.
  • For Percolators – If you use a coffee percolator, you will want to grind your beans coarser than for drip coffee makers to help keep small particles from sifting through the basket.
  • For French Presses – If you use a French press, grind your beans extremely coarse. If you grind your coffee too fine, you will over extract it causing a bitter flavor. It will also be difficult or impossible to push the plunger down in your pot if the grind is too fine.
  • With the best espresso machine possible you should grind your beans extremely fine, almost like powder. The espresso extraction rate should be approximately 20 – 25 seconds in length for a long espresso (2 oz.). This is timed from the moment the espresso leaves the tip of the filter until it reaches its proper 2 oz. dose. If extraction takes less than 20 seconds, grind your coffee finer. If it takes longer than 25 seconds, grind your coffee coarser.

Coffee Quotes

  • “Ah, that is a perfume in which I delight; when they roast coffee near my house, I hasten to open the door to take in all the aroma.”  Jean Jacques Rousseau
  • “Espresso is to Italy, what champagne is to France.”  Charles Maurice de Talleyrand
  • “How sweet coffee tastes! Lovlier than a thousand kisses, sweeter than Muscatel wine!”  Johann Sebastian Bach (Coffee Cantata)
  • “The morning cup of coffee has an exhilaration about it which the cheering influence of the afternoon or evening cup of tea cannot be expected to reproduce.”  Oliver Wendall Holmes Sr. (Over the Teacups 1891)
  • “Coffee should be black as hell, strong as death and as sweet as love.”  Turkish proverb
  • “This coffee falls into your stomach, and straightway there is a general commotion. Ideas begin to move like the battalions of the Grand Army of the battlefield, and the battle takes place.
  • Things remembered arrive at full gallop, ensuing to the wind. The light cavalry of comparisons deliver a magnificent deploying charge, the artillery of logic hurry up with their train and ammunition, the shafts of with start up like sharpshooters. Similes arise, the paper is covered with ink; for the struggle commences and is concluded with torrents of black water, just as a battle with powder.”  Honore de Balzac (The Pleasures and Pains of Coffee)
  • “A morning without coffee is like sleep”.  Author Unknown
  • “I believe humans get a lot done, not because we’re smart, but because we have thumbs so we can make coffee.”  Flash Rosenberg
  • “Sleep is a symptom of caffeine deprivation.”  Author Unknown
  • “No coffee can be good in the mouth that does not first send a sweet offering of odor to the nostrils.” Henry Ward Beecher
  • “Coffee is a beverage that puts one to sleep when not drank.”  Alphonse Allais
  • “Actually, this seems to be the basic need of the human heart in nearly every great crisis – a good hot cup of coffee.” Alexander King
  • “Coffee makes us severe, and grave, and philosophical.”  Jonathan Swift
  • “Without my morning coffee I’m just like a dried up piece of roast goat.”  Johann Sebastian Bach (The Coffee Cantata)
  • “Good communication is as stimulating as black coffee and just as hard to sleep after.”  Anne Morrow Lindbergh
  • “It was a pleasant cafe, warm and clean and friendly, and I hung up my old water-proof on the coat rack to dry and put my worn and weathered felt hat on the rack above the bench and ordered a cafe au lait. The waiter brought it and I took out a notebook from the pocket of the coat and a pencil and started to write.”  Ernest Hemingway

37 Interesting Coffee Facts

  1. Over 53 countries grow coffee worldwide – all of them in tropical and sub-tropical regions. With the exception of Hawaii and Puerto Rico, no coffee is grown in the United States or its territories.
  2. The world’s largest coffee producer is Brazil with over 3,970 million coffee trees. Colombia comes in second with around two thirds of Brazil’s production.
  3. Each year some 7 million tons of green beans are produced world wide. Most of which is hand picked.
  4. Coffee has more than 60 different varieties, but only two coffee varieties have an economic significance: Arabica and Robusta.
  5. A coffee tree can grow to be 25 feet or more. They are pruned to 8 to 10 feet to make harvesting easier and increase yields.
  6. Coffee cherries are the fruit of an evergreen tree. The coffee bean is the seed of this fruit. Each coffee cherry contains two beans.
  7. It takes approximately 2000 Arabica cherries (4000 beans) to produce one pound of roasted coffee.
  8. Arabica and Robusta trees can produce crops for 20 to 30 years under proper conditions and care.
  9. Robusta Coffee has twice caffeine in it than Arabica. Dark roasts generally contain less caffeine than light roasts.
  10. Coffee is the second most actively traded commodity, right after oil.
  11. The estimated value of the export of green coffee is 10 billion dollar.
  12. The USA imports 2.5 million pounds coffee, representing 1/3 of all coffee exported.
  13. Over 25 million people are employed in the coffee industry.
  14. An acre of coffee trees can produce up to 10,000 pounds of coffee cherries. That amounts to approximately 2,000 pounds of beans after hulling or milling.
  15. Almost half of all American adults drink a cup of coffee to start their day.
  16. 80% of Americans consume caffeine on a daily basis.
  17. It is estimated that more than 100 million Americans drink a total of 350 million cups of coffee a day.
  18. On average, men drink more coffee than women.
  19. 37% of coffee drinkers drink their coffee black; the others add sugar.
  20. 57% of coffee is drunk at breakfast; 34% between meals and 13% at other meals.
  21. Coffee represents three-quarters of all the caffeine consumed in the USA.
  22. An ordinary cup of coffee contains about 150 milligrams of caffeine – a “therapeutic dose”.
  23. It takes 42 coffee beans to make an espresso.
  24. Espresso contains less caffeine than any other roast.
  25. Cappuccino is so named because of the drink’s peak of foam, which resembles the cowl of a Capuchin friar’s habit.
  26. To drink coffee in the USA was an expression of freedom, as there was a heavy tax on tea.
  27. The first European coffee was sold in pharmacies in 1615 as a medical remedy.
  28. In the ancient Arab world, coffee became such a staple part of family life that one of the causes allowed by law for marital separation was a husband’s refusal to produce coffee for his wife.
  29. To reduce wrinkles and improving their skin, the Japanese have been known to bathe in coffee grounds fermented with pineapple pulp.
  30. Raw coffee beans, soaked in water and spices, are chewed like candy in many parts of Africa.
  31. Bach wrote a coffee cantata in 1732.
  32. After brewing, espresso coffee contains 2.5% fat and filter coffee contains 0.6% fat.
  33. Black coffee (without sugar or milk) does not contain calories (less than 1 Kcal.)
  34. Caffeinated coffee shows a beneficial effect on alertness and improves performance in a variety of tasks in both day and night sessions.
  35. Up until the 1870’s most coffee was roasted at home in a frying pan over a charcoal fire. It wasn’t until recent times that batch roasting became popular.
  36. Hard bean means the coffee was grown at an altitude above 5000 feet.
  37. The popular trend towards flavored coffees originated in the United States during the 1970’s.