A Coffee Primer

June 28, 2014

As part of my project to learn more about coffee I’ve assembled a simple bulleted list of what I consider to be the basics. Now I never have to wonder about the differences between dark roast vs. light roast (dark is sweeter with less caffeine) or the difference between a latte and a cappuccino (espresso-to-milk balance).

This should take less than three minutes to finish, and when you’re done you’ll be a Level 1 coffee geek, which means you’ll know more than the average coffee snob, but without the attitude.

Basics
Equipment
Preparation
Drinks

Basics

Coffee started in Africa (Ethiopia) in the 9th century and spread to the Muslim-controlled regions, e.g. Egypt, Yemen. From there it came to Italy first through Mediterranean trade routes, and from Italy it made it to Europe and the rest of the world.
Coffee plants are fairly large evergreens–the size of small trees.
The coffee bean is actually the seed from the berries of a coffee plant (see below). Think of a purple grape with a seed in the middle.

The berries themselves usually have two seeds (coffee beans) in each of them, but sometimes they only have one. These are called peaberries.
Coffee berries take seven to nine months to ripen, and move from green (unripe) to yellow, and then red (image above). They turn black when they are dried.
There are two main types of coffee plant (and therefore coffee)–Coffea Canephora and Coffea Arabica.
Arabica Coffee (which comes from the Coffea Arabica plant) is what “fine” coffee is usually made from.
When you hear about “Colombian” coffee, it’s Arabica
Coffea Canephora creates what’s called Robusta Coffee, which is more bitter and less flavorful than Arabica Coffee
Robusta coffee is much cheaper to produce, and as a result is often used like something of a filler for industrial/commercial brands
Robusta coffee is more resistant to disease
Robusta coffee has around 40-50% more caffeine than Arabica
High-quality Robusta is often used in espresso blends
Coffee used to be produced under the shade of large trees. This is the “natural” way of growing coffee and is better for the environment because it supports more wildlife and a more diverse ecosystem. This method, however, has been replaced by farming in direct sunlight to increase yield (the berries grow faster).
“Organic” and “natural” brands tend to market the fact that their offerings are grown the old, “green” way, i.e. in the shade of larger trees. This is often referred to as “shade-grown”.
Brazil is the world’s leading producer of coffee, not Colombia. Colombia is third, behind Vietnam. Vietnam mostly produces Robusta.
Fair Trade coffee (also called “free” trade) is coffee where the company pre-negotiates a “fair” price for the coffee with farmers pre-harvest. It’s designed to give more control over the farming and selling of the product to the farmers themselves, and to prevent them from being taken advantage of by big business.
The basic steps for going from plant to cup are:

Picking the berries (usually by hand)
Sort by ripeness and color
Remove the flesh of the berry (think grapes)
Ferment the seeds (called coffee beans) to remove the layer of plant mucous (mucilage) on them
Dry them. This used to be done by laying them on concrete in the sun and raking them, but now it’s mostly done by hot-air blowers
Roasting dries the bean out and and makes it much larger. Roasting starts when the core of the bean reaches around 200C. Roasting causes caramelization as the starches in the bean become sugars, which gives the dark brown color. Caffeine is lost during roasting, but an essential oil is created, called caffeol, that is largely responsible for a coffee’s flavor

The longer they roast, the darker coffee beans get. Coffees are called light, medium light, medium, medium dark, dark, or very dark based on how dark they look to the human eye, although machines are used to get really precise measurements.
The darker the roast, the smoother and sweeter the coffee tends to be because the beans are more caramelized (sugary) and less fibrous and “planty”.
It’s helpful to imagine two types of oils within coffee. The first are the natural oils that are part of the plant (and therefore the beans). These give the coffee their distinct flavors based on the type of plant, the soil, and the conditions it was grown in. These oils disappear as you roast more. The second type of oils are from caramelization, and they produce the “roasted” taste. They appear more as you approach darker and darker roasts.
As a general rule, the more you roast a bean the more the original flavor characteristics of the bean are cooked out, and the more the “roasting flavor” starts to appear. This can be seen in roasting by two visual indicators: 1) the color of the bean turns from light to dark, and 2) as the beans start to move into the darker roasts you will start to see oiliness appear on the surface of the bean, making it shiny.
French Roast is an extreme roast, where you get extreme flavor but not from the coffee itself, but rather from the roasting process.
Lighter roasts have more caffeine and more bitterness due to the presence of not-yet-destroyed oils that don’t exist in darker roasts.
Since heavy roasting eliminates whatever natural flavors that used to exist within the coffee, and adds its own “roasted flavor”, coffee connoisseurs generally prefer lighter roasts so that the taste of the coffee bean itself can be appreciated rather than the taste of roasting (which can be very similar despite the coffee used).
Decaffeination is done with coffee beans are still green, and is accomplished via either soaking in hot water or by steaming and then using a solvent that dissolves the oils within the beans that have caffeine in them.
Just like pepper, coffee is best when it’s recently ground. Coffee enthusiasts buy whole beans and grind them as close as possible to preparation time.
A Barista is someone who works at a specialty coffee shop and serves espresso-based beverages. The word is Italian, and as one might guess from the name it means someone who works behind a bar. In the past it included not just those who served coffee, but also alcohol-based drinks. Unsupervised Learning — Security, Tech, and AI in 10 minutes… Get a weekly breakdown of what's happening in security and tech—and why it matters.
While Starbucks employees are called baristas, the term among coffee aficionados and most Europeans is applied only to those who have attained a high level of skill with coffee blends, espresso, quality, coffee varieties, roast degree, espresso equipment and maintenance, latte art, etc. So some Starbucks employees undoubtedly know their stuff, but just because one has the title of “barista” in America doesn’t mean they do.
There are basically two types of coffee grinders: burr and blade. Burr grinders are superior and more costly because they produce more uniformly shaped grinds, and you can control the coarseness (size) of the grind. Blade grinders are cheaper and produce randomly shaped fragments that tend to lead to poor flavor. Of the burr grinders there are also two types: wheel and conical. Conical are the best of those two, and thus are the most expensive.

Preparation

That’s what coffee is, so now let’s talk about how to get it ready for consumption.

There is great similarity between the concept of roasting coffee beans and cooking fine steaks. Those who truly know about and appreciate fine steaks generally shun the idea of cooking them beyond medium rare, with most preferring rare. The reason is that as you cook the steak more, just as with coffee beans, you remove the qualities that made it unique and of high quality in the first place. In short, if you’re going to cook/roast something to that extreme there’s no point in starting with something expensive since it’s all going to end up tasting the same anyway.
The coarseness of a coffee grind is a factor in preparation and flavor because it determines how much water gets exposed to coffee. Basically, if it’s a coarse grind then you might not get all of the coffee’s essence out of a given grind, while water will thoroughly penetrate and extract a fine ground. Automatic coffee makers use a fairly fine ground, but not as fine as an espresso machine. French Presses use a more course ground.
Brewing coffee is broken down into a few types, but they all involve exposure of the beans to water at high temperature in order to extract the flavor of the bean. Here are the main two methods:
“Steeping” is the most common way to brew. With this method you simply expose coffee grounds to hot water, let them mingle for a bit, and then let the resulting liquid out through a filter. French Presses are the most common tools used for steeping. Standard coffee makers use this system as well, but the coffee interacts with the water for less time, resulting in a weaker flavor than a French Press. Also, coffee makers often can use paper or metal screens as the filter, and french presses usually use metal filters. Metal filters are considered superior to those made of paper because they don’t change the flavor. Steeping is usually done with medium to coarse grounds. Also, with a French Press you control the steep time, which affects flavor.
Espresso (there’s no “x” in it) is also created using hot water mixing with coffee, but the grounds are much finer for espresso and the water is introduced to the coffee using pressure. Both the ground fineness and the pressure result in more water-to-coffee contact, which means more of the coffee’s contents are extracted (and at a higher rate), resulting in more caffeine and a stronger flavor. The pressure used also creates a characteristic foam on top. Espressos are the base of many popular coffee beverages, such as lattes, cappuccino, macchiato, and mochas.

My favorite way to make coffee: (based on world-class Barista technique

Get a fresh batch of your favorite coffee in its whole bean form, i.e. not ground yet
Grind it yourself using a high-quality conical burr grinder
Combine 70g of grounds of your coffee per liter of filtered water into a quality French Press
After combining the water and coffee, use a chopstick to briefly whisk them together. Nothing extreme, a few good swipes. Just make sure full uniform contact is made.
Brew for four (4) minutes with no lid on the press. You’ll notice a “bloom” forming.
At the four minute mark, skim the bloom off with a spoon, trying to get as much as possible, but not stressing it too much
Put the lid on and pour.

Aeropress

Another top method, which is becoming my favorite, is to use an Aeropress.

The Aeropress handles things a bit differently than the French Press. It’s idea is to:

Use cooler water (this produces sweeter / less bitter coffee)
It exposes the coffee to the water for less time
It uses pressure to speed up the extraction

So the idea is that you expose the coffee to water for less time, but you use cooler water and pressure to get the perfect extraction.

The result—supposedly, and I’ll vouch for it here—is that it produces the smoothest and richest cup of coffee that you’ll ever taste.

My favorite methods are these, in order:

Aeropress
French press
Pour over
Drip

Drinks

Go to any coffee shop and you’ll notice an assortment of coffee beverages. Latte-frap-capo-chino-whatever. Here’s what they really are:

Most of the popular coffee beverages you see at a place like Starbucks are modified espressos. The major ones include:
An “Americano” is a watered-down espresso, a name supposedly started in WWII.
A Cappuccino is a Latte with less steamed milk that a latte, usually served in a porcelain cup. Attaining the perfect balance between the espresso, the milk, and the foam is an art form.
A Latte is 1/3 espresso and 2/3 steamed milk
A Cafe Mocha is a Latte with chocolate added, usually via syrup
A Macchiato is another espresso beverage with two main variations. “Macchiato” means “stained”, and a espresso macchiato is an espresso “stained” with a little bit of steamed milk. A latte macchiato is a steamed milk with a “stain” of espresso.

This primer is a work in progress, so if you have any corrections or ideas for what should be included, please let me know. ::

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