The Art & Science that creates a brilliant cup of coffee are the result of three independent processes that ideally, progressively highlight each subtle influence.
Growing and harvesting coffee is a labor of love dependent on instincts aquired over generations. Often the vinyard analogy is used, as there is a very specific process that needs to be followed in order to ensure the crop reaches it's fullest potential.
There are two species of the plant: Coffea Arabica, the most commonly consumed in North America, and Coffea Robusta.
The vast majority of harvested coffee comes from tropical and sub tropical regions.Just like wine, soil composition, altitude, weather, harvesting and drying methods have a great impact on the potiential flavor of the brewed coffee.
Coffee blends from a single geographical region are called " Single Origin".
Many methods have been developed in the search for rendering the roasted beans into the perfect cup of coffee. Recently, for example, North America has witnessed a rise in the "Espresso" method where water is forced through the coffee with precise pressure over a short period of time, producing an ounce and a half of extracted coffee.
Yet, the most common brewing method used today, in most parts of the world, involves "dripping" water from above, through ground coffee and a filter. While this allows for a larger beverage size, most often it does NOT result in consistent extraction because of the inability to control all the variables noted above.
Often the result is a bitter over extracted flavor or a flavorless cup of underextracted brown water!
The primary problem with automated drip filter systems is, the first half cup/pot captures the ideal flavors but with extended exposure to water, the less appealing flavors of the bean are released and the result is a bitter flavor.
This is largely because the coffee is "stacked" below the water source as opposed to being simultaneously immersed in it. What happens is that the water to coffee contact time cannot be controlled evenly across all of the ground coffee.
There's a lot that goes into realising the exceptional flavor that is enjoyed in a spectacular cup of freshly brewed coffee. Growing and harvesting the variety of bean, the geographical location and the method of harvesting create the potiential each pound of green beans begins with.
Roasting is a fine art, developed over centuries and depends on temperature, length of roast and airflow during the process to ensure a desired flavor.
Brewing correctly is done by prescisely controlling the key variables in the brewing process: freshness of the bean, the grind, the water temperature and most importantly the exact time the ground coffee is in contact with the water (dwell time). When done with precision the result is an extraction of the delicate flavors and aromas both the farmers and the roasters have lovingly crafted into the bean.
The three primary stages of influence in making a spectacular cup of coffee are Harvesting, Roasting and Extraction (Brewing).
The fine art of effectively roasting coffee is not to be under valued. Coffee roasters are like master chefs,taking into account the annual weather, the harvesting method and the geographical origin of the green beans, to develop "roasting profiles" that highlight the key flavors they wish to feature, eg: "chocolate, floral, citrus".
In order to gently coax out these subtle undertones roasters depend on very specific measurements of time and temperature. The roasting process yields the primary roast catagories of "Light", "Medium" and "Bold" which are then further defined by batch size to create specific roast profiles,eg: Cinamon (a "light roast"), City ("Medium") and Vienna ("Bold")
From this point the true art is further defined, very much like two chefs might achieve wildly different tastes from the same cut of meat. The equipment used and and airflow result in a final result that achieves the targeted chemical and physical changes in the beans that will produce the flavor, body and aroma the roaster seeks.
Once the beans have been lovingly grown, and the roasting process has been artfully accomplished the final step in the "bean to cup" process is the extraction of the flavors and aromas by brewing them in the right ratio with water.
As you might expect, this stage also involves many critical variables; how finely ground the coffee is, what temperature the water is, the coffee to water ratio and most importantly controling precisely the exact time the water is in contact with all the ground coffee.
Precision with "Vacuum Brewing"
The only method where all of the variables previously noted can be independently precisely controlled in a variable beverage size, was invented in 1840 by Robert Napier. Called the Syphon or Vacuum Pot (Vacuum extraction) system. How it works is illustrated above or see a non automated version by Hario in their very cool video here; http://vimeo.com/98453791
The vacuum system allows for the brewing time to be precisely controlled. By removing the heat source away from the lower chamber at the precise moment defined to extract only the appealing flavors of the ground coffee, a vacuum is created and through negative air pressure, the brewed coffee is pulled away into the lower chamber through a filter instantaneously.
The perfect water to coffee ratio can be scientifically measured by testing the Total Dissolved Solids (TDS) and has been defined precisely by the Specialty Coffee Association of America (SCA) as the "Gold Cup/Golden Cup" standard.
A targeted TDS value can be defined for any blend profile of coffee beans, roast profile and beverage size.
The original vaccum concept, which pretty much remained constant for more than 180 years, has not kept up with the evolution of our demands on our time. The challenge with the original method was that despite producing a superior extraction, the system required a removable heat source and a person to manage the precise brewing time by removing the heat source so that only the ideal flavors were extracted.
While this was effective for the days gone by or even today for a "lazy Sunday morning special cup", it is not exactly ideal for today's super time sensitive market and multitasking consumer.
Yet there was just no way to get an "Automated" Vacuum Extraction.