Coffee

Coffee is the beverage produced from the washed, processed and roasted seeds of the coffee plant (Coffea canephora or C. arabica), which are typically ground and steeped in water. Coffee as we know it was probably first made in Sufi monasteries near the town of Mokha in Yemen in the mid-15th century. Within one hundred years, it had reached Turkey, northern Africa, Persia, and the remainder of the Middle East. 

In 1600, Pope Clement V decreed that coffee was a Christian beverage (it was looked upon as a Muslim drink by many people), which led to the first coffee houses opening in Europe in 1645. Thirty years later, there were 3,000. The Dutch became large importers of coffee beans, which they in turn planted in Java and Indonesia. 

Interestingly enough, coffee houses also became centers of political debate, and were regularly closed by both secular and religious authorities. Coffee houses were banned in Mecca from 1512 to 1524, and Charles II of England attempted to ban them in 1676, though he backed down due to popular sentiment. It was banned in the 17th century in Ottoman Turkey, as well. Neither Mormons nor Seventh Day Adventists drink coffee. 

In the United States, both the Revolutionary War and the War of 1812 stopped British tea imports. Coffee became a patriotic drink, with mid-19th century technological advances, coffee became a staple in America. In 1952, the Pan American Coffee Bureau advocated for a "coffee break", which is now standard in the American workplace.

Today, coffee plants are grown in a belt that stretches from Mexico in the north to Madagascar in the south and reaches around the world. It is the primary agricultural export for twelve countries, and is the seventh most valuable legal agricultural export. 

Coffee contains caffeine, a bitter alkaloid substance that is a central nervous system stimulant, and affects everything from heart rate to memory to alertness. Caffeine is psychoactive, and is habit forming — withdrawal symptoms can include headaches and lethargy. It also increases urine production and gastrointestinal motility.

Caffeine is destroyed in the roasting process, with higher levels of roast having lower levels of caffeine. Some coffees are decaffeinated, typically through the Swiss Water Process, which soaks the green beans in water, thus extracting the caffeine. 

Coffee "cherries" are picked as the bright red fruits of the coffee plant. The fruit is removed from the seed (the coffee "bean") in one of three ways: Wet processing, Dry Processing, or a hybrid style.

In the wet method (also called washed), coffee cherries are put into a large vat of water. Unripe or low quality fruit floats, and is skimmed off. The fruit is pressed through a screen to abrade the surface. Traditionally, more water was then used to start an enzymatic "fermentation" that dissolves the pulp and pectin layer between the skin of the fruit and the seed. This typically takes 24-36 hours, and must be carefully monitored. After fermentation, the beans are washed in more water to remove any pectin or pulp fragments. 

The beans are then laid out in rows to dry in the sun and turned every six hours to reduce mildew growth. The goal here is to dry the beans until they are 12-13% moisture. They are then machine dried to 10%, and run through a hulling machine to remove the silverskin, a parchment-like covering over the bean. 

In many African countries where water is at a premium, a dry process is used. In this method, the coffee cherries are harvested and picked through to remove twigs, rocks, and other foreign material, then the unripe and spoiled cherries are removed. The cherries are then raked into rows and dried in the sun for up to four weeks. This is much more risky than the wet process, as mildew is a serious problem. Overfermentation can lead to bizarre aromas in the finished coffee -- that lovely blueberry aroma in many Ethiopian coffees? That's overfermentation. 

In Brazil and Indonesia, a hybrid process is used, in which the cherries are run through a pulping machine to remove the outer skin. They are then stored for a day or two, after which the pectin is washed off, and the beans are halfway dried to about 35% moisture content. 

Regardless of the process used, milling comes next, where whatever is left covering the coffee beans is mechanically removed.  The green coffee beans are then sorted and graded, then packed into jute bags, where it is shipped around the world. Green coffee is stable for about a year, but given that there are many harvests in dozens of countries, the supply of coffee is fairly stable at any given time. 

Roasting coffee is a fascinating blend of art and science. In order to unlock desirable aroma and flavor compounds from coffee beans, they must be roasted, which takes two forms: Fluid-bed roasting, or indirect fired roasting. In fluid bed roasting, hot air is forced through the coffee, which transfers heat to the beans, and tosses them in the air. Old popcorn poppers utilize this technology, and can be hacked to roast small amounts of coffee beans. Most commercial roasters use indirect fired roasting, where a metal drum is heated by a flame. The drum turns, exposing coffee beans to heat. Most roasters operate at a temperature around 500 degrees Fahrenheit and can roast beans in between 10 and 30 minutes.

As the beans roast, many changes happen from both a physical and a chemical standpoint. A good roaster uses both technology and their senses to determine when coffee beans are properly roasted. At its most basic, there is a port on the front of the roaster called a sightglass which allows visual confirmation of bean color. There is also a small opening into the roasting chamber with a small device that can pull a few beans out of the drum. Smell is important here, as coffee will begin with a legume aroma, which changes from hay to wheat to typical "Maillard" aromas, then to carbonized sugary aromas towards the end. Finally, coffee beans "crack" -- first at about 400 Fahrenheit, and then at around 435. These cracks signal important chemical and physiological changes in roasted coffee beans. Once coffee beans are roasted, they're "dropped" into a hopper and cooled quickly. The freshly roasted beans now give off carbon dioxide for a few days, and are bagged for sale.

There are different names for the different roasts, but they're subjective and confusing. The Agtron scale is a series of porcelain tiles that are colored to represent roasted coffee beans. This helps with standardization for roasters, but coffee drinkers will rarely see Agtron scales.

Oxidation is the enemy of well-roasted coffee, and oils oxidize. If you see oils on the outside of coffee beans, they're going to be oxidized, which leads to off flavors in the cup. Once coffee is roasted, quality begins to degrade. Roasted coffee should be consumed within two weeks. Bags should have a "roasted on" date, and important information like region, mill, cooperative, process method, and if you're lucky, who grew the coffee. It is common for specialty coffee to be bagged in a Mylar lined bag with a one-way valve (to let carbon dioxide out), and weighing about 12 ounces. 

There are a few important considerations if you're striving for a good cup of coffee:

1. Water

If your water quality is good, use it. If it's not, filter it, or buy bottled water. You also want your water to be between 200 and 206 when pouring.

2. Equipment

Get a burr grinder. These can range from $35 to hundreds of dollars. Mine is $150, and has lasted 8 years with regular cleaning (once a week) and little other maintenance (other than new burrs). It's going to seem expensive, but your grinder has more to do with a quality cup of coffee than almost anything else. A French Press is a great place to start, and as you grow in this, a V60, Chemex or Aeropress will probably find its way into your routine. They're all slightly different cups of coffee. A good instant read thermometer will also come in handy (for water temperature), as will a timer and a digital gram scale. 

3. Coffee

Buy whole beans, and find a local supplier. You're looking for a roast date on the package, and you should use it within two weeks. Don't put coffee in the freezer; I leave mine in the original bag in a cool, dark place. Most good roasters use bags with one-way valves, which keep oxygen out. This is a good thing, as oxygen is the enemy of coffee. Personally, I want to see no oils pushed to the surface of the beans - free oils mean oxidation which means off flavors in the cup.

4. The Magic Ratio

6g of coffee to 100g of water. I might take it to 7g/100g if you need to, but 6g gives me transparent flavors, which is what I want.

5. The Routine (for a French Press)

Plug in the electric kettle and grinder, get out the coffee cup, Thermapen and scale. I weigh out 42g of coffee, and put it in the grinder. Turn the grinder to a coarser setting, so the grounds are trapped by the metal filter of the French Press. I can tell by the sound the kettle makes when it's close to 200, so I'll measure the water temperature at this point. I tend to test new coffees at 202, which is a good round number while you're getting used to this. When the water hits 202, start grinding the coffee. Once that's done, add the coffee to the Press, put the Press on the scale, and add 150g of water, making sure all the grounds are saturated. Start a timer and count for 45 seconds. This is called blooming the coffee - you'll see it foam and bubble as carbon dioxide is released from the grounds. Once the timer goes off, add the remaining 550 g of water, remove the Press from the scale, put the filter assembly barely into the top of the Press, and start your timer for 3 minutes. After 3 minutes goes by, give the coffee a stir, and push the plunger down slowly, trapping the sediment in the bottom. If you're going to drink the coffee quickly (within 10 minutes), you can serve it from the Press. If not, pour the coffee into a warmed thermal carafe and serve from that. 

Smell the coffee at every step: whole beans, freshly ground, wet during bloom, and in the final cup. Look for aromas that stay the same from dry to wet, and those that are different. And yes, the routine looks complex and difficult, but you'll pick it up quickly.

Some common brewing methods include the aforementioned French Press, the Hario V60, Kallita Wave Dripper, and Chemex (which are all pour-over methods), [ingredient=espresso espresso], the Aeropress, vac pots, percolaters, or even the exotic siphon brewer. Each method has strong and weak points, and most of them can be tweaked to make coffee that you like.