Coffee: A brief background

Coffee is the second most traded commodity in the world.  Right behind crude oil.  Yet many who drink it are unaware that coffee is essentially the pit of a cherry.  The coffee plant is an evergreen shrub that grows around the world in equatorial regions and moderate climates.  The berries are harvested and seeds are removed and dried.  There are two commercially viable species of coffee plants; Robusta and Arabica.  Both are native to several regions of Africa.

Robusta is not as susceptible to disease and is easier to grow in direct sunlight.  Coffee is traditionally an understory plant and grows better when provided some shade and would burn if grown in the direct sunlight of a clear-cut plantation.  Over the past 40 years, there have been new varieties developed to allow for coffee to be grown in the sunlight.  But think about buying a tomato nowadays, especially in the winter; they taste nothing like a real tomato.

Additionally, Robusta contains more caffeine than Arabica.  You may think, "Awesome, more caffeine."  Caffeine, however, imparts a bitter flavor that often needs to somehow be masked by large roasters.  Over the past 30 years or so, large roasters have been slowly increasing the amount of Robusta beans in their coffee and each time they do we become more accustomed to bitter, burned coffee.  This is also the reason that light roast coffee made from sub-par beans tastes bitter.  The longer a coffee is roasted for the more caffeine is removed and the less bitter the coffee becomes.  This is why dark roasts have become popular in the recent past.  Many drinkers were looking for a less bitter brew and gravitated to French and Italian roasts. 

Arabica, on the other hand, has a more delicate flavor and, because its flavor profile is not as influenced by the caffeine, much more can be done with the beans.  Everything matters from the time the coffee is planted to the time it reaches your cup.  Arabica plants are more susceptible to disease and less tolerant of bright light and therefore more expensive to grow.  Any Arabica will taste better than any Robusta, but Arabica is best in the hands of skilled farmers and roasters.  Just as many people consider wine something more than an alcoholic beverage that will get you drunk, more and more farmers, roasters, and drinkers see coffee as something more than what you drink to wake up.

Brewing at home

As we learned above, the coffee plant itself, the soil in which it is grown, the amount of shade it gets, the quantity of rain, the temperature, when it is harvested, how it is dried, the skill of the roaster, and the way it is ground and brewed; Everything effects the way a particular coffee tastes.  So don't screw it up when it comes to brewing it!

There are several ways to brew great coffee at home.  All of them, however, require a departure from how the typical coffee drinker thinks about coffee.  We'll go through some of the methods here and in the process learn about grind size, extraction time, water temperature, and filtration.

Grinders

It is not sandwich time.  It is grinder time.  No, coffee grinder; not the sandwich.  Coffee grinders are as important as the coffee you will put in them.  There are two basic types: bur and whirlybird.  Most people are probably familiar with whirlybird grinders.  These are the horrid devices that you put coffee into and it is then beat to hell by a couple of blades spinning very quickly.  The main problem with this device is that there is no uniformity in the grind size nor is there a way to adjust the grind size.  The blades don't really grind the coffee, they pulverize it into sizes ranging from dust to large chunks.  This is problematic.  The finer the coffee grinds are, the more surface area there is for flavor extraction.  And as we'll learn in the next section, the brew method you choose and the amount of time it will take to extract the best flavor from your coffee is closely related to the grind size.  If some grinds are big and others are small then you'll end up over extracting the coffee from the finer grinds, which will lead to a bitter taste, and under-extracting from the larger grinds, which will lead to an undeveloped flavor.

A much better option is a burr grinder.  This was not invented by Aron Burr.  A burr grinder truly grinds the coffee rather than beating it up until it submits to breaking apart.  While pricey, again I'll say that the grinder is just as important as the brewing method and the beans you are using.  Uniformity in size and adjustability are the two main factors to consider.  For advice on specific grinders, check out this Coffee Geek article.  This article is specifically geared to espresso but the grinders we recommend for daily use are all discussed in this article.

Brew methods

Drip

When most people think of coffee this is the device that comes to mind.  And it is possible to get a good cup of coffee from a drip coffee maker.  Unfortunately, not all drip makers are created equal.  In fact, most of them are downright crap.  When people start to get into specialty coffee they usually abandon this piece of equipment for the simple reason that the one they currently have is of the crap variety and it is cheaper to go with a pour over method.

The grind size, the extraction time, and the water temperature are the three major factors you have control over when brewing coffee.  A drip machine eliminates two of these factors.  It is therefore important that the drip machine be able do these two things well.

Extraction time is the major problem with most drip coffee makers.  Extraction times with other methods of brewing can range from 30 seconds to 4 minutes.  Much longer than 4 minutes, regardless of grind size, and the undesirable flavors quickly emerge from the coffee and foul your brew.  Most drip coffee makers will take far longer than this to brew a pot and this is a very bad thing.  Some will take over 15 minutes to do what should be done in 4!

So, if you are going to use a drip coffee maker then you have 4 choices.  4 is the number of drip coffee makers that the Specialty Coffee Association of America has certified to meet their strict standards.  They are:

  • Technivorm Moccamaster
  • Bunn Phase Brew 8 Cup Coffee Brewer
  • Bonavita 8 Cup Exceptional Brew Coffee Maker
  • Lance Larkin BE 112 Brew Express

If you want to brew at home with a drip coffee maker then you should buy one of the above coffee makers.  If you don't want to do that then read on!

Pour-Over

Contrary to what you may hear, pour-over coffee is not new.  "This is a new way to brew coffee, you haven't heard about it because it just came over from Japan."  A barista told me that once.  This method of brewing was actually popularized by the Melitta Company.  Melitta Bentz was the inventor of the coffee filter in 1908.  She was also German, not Japanese. Prior to this coffee was brewed in percolators or with linen bag filters and both of these brew methods had problems.

There are several important factors to consider when brewing with this method, but for the most part the concept is simple.  Put the coffee in a filter, pour hot water over it and let it drip into a mug.  Very similar to drip but with much more control over the brew. 

  • Grind size: The size of the coffee grounds informs the extraction time.  If the grind is finer the extraction will take more time.  Also, if the grind size is smaller the extraction needs to take less time.  So it is important to find a correct balance and many roasters publish the recommended extraction time.  This extraction time will help you determine the correct grind size.  If your pour is going too fast then you'll need to make your grind smaller.  If it is taking more than 4 minutes you probably have too fine of a grind.
  • Weight ratio:  Most people use a scale when determining how much coffee and how much water to add.  Yep, it just got all sciencey on ya.  A good starting ratio is 16:1.  In other words, if you put 25 grams of coffee into the filter you would add 400 grams of water.  This will yield about 15 ounces of coffee.
  • Water temperature:  The temperature of the water you pour onto your coffee should be between 195º and 205º Fahrenheit.  Do not use boiling hot water.  If you use a tea kettle the water will probably be far too hot if the kettle starts to whistle.

Another thing to consider is what is known as the "bloom pour".  When you first add water you want to pour about twice as much water as you have grinds (by weight) and wait about 30 seconds.  This helps to release the flavors from the coffee and is included in the total extraction time.

Finally, another note about extraction times.  There are several different pour-over devices out there.  Chemex, Bee, and V60 are the major ones that you are likely to come across.  The design of the device (the V60, for example, has a swirl pattern in the sidewalls that moves the water in a certain way) as well as the thickness of the filter (Chemex has a very thick filter, for example) also effect extraction time.  A Chemex brew should always take longer than a V60.  So if you are brewing for 2:30 in a V60 you may be around 3:30 or 4:00 in a Chemex.

French Press

A French Press is as close to "cowboy coffee" as you probably want to get.  Cowboy coffee is simply taking a cup of hot water and dumping in some coffee grounds then using your mouth to filter it as you drink.  You would do this if you were lost in the woods without any luxuries of modern life but you for some reason had coffee and a mug.

The French Press gives a unique "dirty" taste to coffee.  Whereas a paper filter removes nearly all particles, a French Press leaves the majority of large particles in the coffee.  A French Press has no filter, just a wire mesh that pushes the coffee grinds to the bottom so the coffee can be poured without getting the bulk of the large grinds into the mug.  This method makes a very muddy cup of coffee and is the disdain of many specialty coffee folks.  If you have a pour over device and a French Press do this experiment:  Brew a pot in the French Press and filter it through the pour over device.  You'll be amazed at what is left in the filter. 

It can, however, be good for bringing out flavors, especially in dark roasts where most of the bitterness is already gone.  One mistake people often make, though, is leaving the coffee in the French Press while serving.  The coffee should be decanted as soon as the plunger is pressed.  Otherwise, it is still in contact with the coffee grounds and is still extracting flavors.

French press coffee is generally made with a much larger grind.  While there is some debate about this, it is generally recognized that this prevents grinds from sneaking past the plunger and getting into the coffee. Because of the larger grind, the extraction time is slightly longer.

Espresso

Espresso is brewed in small, strong amounts using pressure and very fine coffee.  The coffee is packed into the portafilter part of the espresso machine at a pressure of around 35lbs.  This high pressure, along with fine coffee, means that water will never just drip through the portafilter with the help of gravity alone.  The espresso machine must provide hot pressurized water to the portafilter so that the coffee can be extracted.  It then falls out into the cup below.  Because of the fine grind, it is very important that the coffee be ground within a minute or two (some people say 30 seconds) of pulling the shot.  It is also important that the extraction time be short.  After about 30 seconds the coffee has been fully extracted and any more time will ruin the shot.

There are several espresso machines targeted at the home-use market that have pressurized portafilters.  The attempt here is to try and idiot proof the machine.  An espresso machine with a pressurized portafilter means that the portafilter has an actual valve inside that won't allow the espresso to drain out until it reaches a desired preasure.  This eliminates the need for tamping the espresso in the portafilter to a desired preasure.  The user therefore does not need to know how hard they need to push to make sure the espresso is properly tamped nor do they need a tamper with which to do this.  Usually this pressure device can be easily removed with instructions found on various barista and homebrew forums.  Removing this pressure valve can turn your relatively cheap espresso machine into something that can be considered a "real" espresso machine.