The Most Extensive Moka Pot/Stovetop Espresso Guide on the Internet

Source: Me! 

The purpose of this guide, besides making unattainable hyperbolic statements, is to touch on many aspects of making Moka pot coffee.  This post is broken into four parts: Introduction, Brewing/Tips, Cleaning, and More Information. I spent considerable time writing these set of posts so please leisurely read through them reflecting upon each section.  It will be broken into 3 posts over roughly seven days.  Please leave a thoughtful comment, if you have any questions, critiques, or revisions I should make.  Without further ado, here is the first part of the "Most Extensive Moka Pot/Stovetop Espresso Guide on the Internet."

Introduction:  First, one point on nomenclature.  When I refer to a Moka pot, stovetop espresso maker, or coffee percolator, I am referring to Bialetti's Moka pot, the most popular manifestation.  While there are other products that use the same principle of steam to make coffee on a stove, most people have some version made by Bialetti.  

The 5 parts of the Moka pot

How does a stovetop espresso maker work?  It is composed of roughly three components: the base with a pressure valve which holds the water; the basket which holds the coffee; and the "collecting chamber" which the coffee brews into.  Additionally, there is  the metal filter and the "O" ring which ensures a good seal for the pressure to build and that the coffee grinds don't infiltrate your end product.  The Moka pot creates stream by boiling water in the base that pushes water into the coffee hopper.  Then, the water comes into contact with coffee, brewing, and then goes through the filter above the hopper, and into the collecting chamber.  The whole process from heating the water to drinking the coffee is about 5-10 minutes.


I will focus on the "3 cup" Moka pot which I own as the basis for this guide.  Remember, the designation of "3 cups" means three small espresso cups resulting in ~6-7 oz of liquid in total.  It does not make 3 American-sized cups of coffee.  If you want 3 large cups of coffee, the Moka pot is not for you, unless you buy the 12 cup Moka pot, which makes 25 oz of coffee. For a breakdown of all the different sizes of the Moka pots, look here.

Unfortunately, I must disabuse you of the notion that the Moka pot makes espresso.  It does not.  Let me repeat that.  Stovetop espresso makers do not make espresso.  They make strong coffee.  Let me explain why.  Espresso is brewed using around 9-10 bars of pressure.  The Moka pot is capable of around 1.5 bars of pressure.  This amounts to a difference in consistency, taste, and appearance, principally the lack of "real" crema you would see on good espresso.  Additionally, the temperatures involved are different.  Since Moka pots rely on steam to push water up, it requires the water to reach boiling, 212 Fahrenheit.  Espresso machines, ideally, keep the water temperature around 202-5 Fahrenheit.  What is the difference you may ask?  Boiling water can burn the coffee damaging the delicate flavors of the coffee you just spent 20 dollars on.  A rule of thumb for most coffee preparations generally advise to never allow boiling water touch coffee.  Technically this is true for the Moka pot as the steam pushes non-boiling water into the coffee grounds (I think), but nevertheless a higher temperature is involved than in making traditional espresso.  While espresso machines and Moka pots use pressure, the difference in pressure produced is significant.

Stainless Steel

Aluminum

If that wasn't complicated enough, there are two different versions of the Moka pot (besides the different sizes): aluminum and stainless steel.  The aluminum version is the first Moka pot made by Bialetti and appears to be the most popular version, probably due to tradition, modern aesthetics, and the cheaper price.  Unfortunately, there is one large issue with the aluminum version.  Aluminum can impart a "metallicy," bitter taste to the coffee.  To counter this, people "season" their pots by allowing a film of coffee oil cover the top chamber by not thoroughly washing it.  I will address this later, but its an important issue to remember.  The stainless steel Moka pot generally does not impart the aforementioned metallic taste. [Source for the two pictures is Bialetti's website]

In addition to the aluminum and stainless steel Moka pots, Bialetti makes one's that steams milk and brew coffee resulting in a cappuccino, and ones that are electric. If that wasn't enough, other companies like Bellman have ones with steam wands!

Brewing Steps and Tips:
First, let me walk you through how to brew with the Moka pot.  At each step, I will introduce some helpful tips and hints to improve the end product.  If you want a quick "how to," search James Hoffman's video on the Moka pot, and watch it.

0.  Quickly wash out the base part with tap water and wet the the metal filter and O ring on the collecting chamber.  I think it helps reduce the "metallicy" taste, especially if the Moka pot has been sitting for a few days with use.

1.  Pour water into the base stopping where the pressure valve is.  Any more and the water will prematurely contact the coffee grounds.

At this point, there are two "schools of thought."  The first school of thought is to use cold water.  The reasoning is more of habit than anything else.  Reconsidering this reasoning, it really is not a "school," but that of uncritical thinking.  The second school of thought is to boil the water in a teapot and pour this into the base.  In doing so, this prevents the the stove from heating the whole Moka pot to an unpleasant temperature for the coffee which might cause it to burn.  I'd recommend this method.

Be sure to use quality water!  Water right out of the tap is drinkable, but it can also introduce unwanted tastes into your coffee.  I suggest using a water filter to minimize the introduction of foreign elements into your perfect brew.  Consider using a Brita filter or the like

2.  Grind the coffee.  Try to ensure an even distribution and flat surface.  The hopper must be filled completely for the Moka pot to function properly.  If it isn't, wonky things will happen...

Like so!

This is sticking point for me.  I have read and heard that the grind for Moka pot coffee should be just above an espresso setting on your grinder.  They have forgotten that we are making strong coffee not espresso.  From my experiences, a medium grind has produced the best results avoiding the bitter, over-extracted coffee that plagues the Moka.  If you want to experiment with different grind settings, please do!  I have found that the finer one goes, the more bitter the coffee tastes.     

3.  Screw on the top chamber with a dry towel (if using hot water).  Make sure it is tight enough as the coffee can seep out where the base and the top chamber meet.  Turn the stove to low-medium heat.  On my gas stove, I ensure that the flame isn't touching the pot.  Don't want it to burn or melt.

4.  After a few minutes, the coffee will begin to come out of the spout in the upper chamber.  After about half the chamber is filled, I cut the heat and remove the pot from the stove.  I try to limit the watery end of the brew from diluting the quality coffee brewed in the beginning.  However you do it, please do not leave the Moka pot unattended!  This could lead melting, but more importantly the more the coffee is heated after brewing the bitter it gets.

5.  Pour the coffee into your favorite coffee receptacle.

6.  Before drinking, quickly run water over the collecting chamber to prevent coffee oils globbing all over the aluminum.  By doing so, this ensures a nice uniform oily film to prevent a "metallicy" taste in future brews and doesn't allow the pot to get too dirty and gross.  Proper "seasoning" of the pot should look something like this:

A "Seasoned" Moka pot: Notice the light and even coffee oils.  Any thicker it may be time to clean it.

End of Part One.  Please come back in a few days for Part Two: "Cleaning the Moka pot."  I hope you enjoyed reading it, if there are any errors on the science of it, please comment below, or if you simply want to leave a pleasing message.  For Part Two, click here.

Best,
Jack