Level of Extraction

Principle #2 of making good coffee – Managing the level of extraction

When one first get introduced to making your own coffee, or when you are introduced to a new way of making coffee.  There is some questions that people ask me often like: “how fine should I grind my coffee?”.  Most of the answers on these questions will affect extraction, so I decided to have a post about extraction.

Principle#2 in making good coffee is managing the level of your coffee extraction.

Managing extraction is super important since incorrect extraction will lead to either over or under extraction.  As a rule of thumb, under extraction will lead to sour or acidic tasking coffee, but you can also get salty tasting coffee.  Over extraction can be recognised by a bitter, but tasteless or hollow tasting coffee.  Only when you hit the sweet spot in-between, will your coffee hit the spot with intensity of flavour, balance and lingering pleasant aftertaste.

Extraction level can become very scientific by the use of a refractometer, which is a device often used by especially fruit farmers.  This device can measure level of refraction and since light refract more when traveling through suspended solids it can measure percentage of solids within any liquid.  Because of this, it can also measure extraction level of coffee!

We will try and keep things simpler here 🙂

The following will affect extraction, separated by brewing category as described in Brewing Methods:

Extraction factors for all methods:

  1. Grind size
  2. Water temperature
  3. Brew ratio

Extraction factors for steeping methods

  1. Agitation
  2. Steeping time

Extraction factors for drip or pour over methods

  1. Pouring technique

Extraction factors for pressure or vacuum methods

  1. Pressure applied
  2. Compaction
  3. Distribution

Let us expand just a little into each of these, but play around with all the variables and have fun!  Coffee making is a science for sure but also an art form, so do not let these factors steal your coffee joy.

  1. Grind size: this will affect extraction for all methods, since smaller particle size makes for bigger surface area, so finer grind = quicker extraction.  Various methods also require different grind sizes although some methods can be used with various grind size such as the Aeropress.  Here are general grind sizes per preparation method as a rule of thumb:
    • Super Fine: Turkish Coffee
    • Very fine: Espresso
    • Fine: Mocha Pot like Biatelli
    • Medium to fine: Pour over like V60, Chemex or other cone filter equipment as well as Aeropress
    • Medium: auto drip machines
    • Medium to coarse: Vacuum pots
    • Coarse: French press
  2. Water temperature: Water should not be too hot, else you will get over extraction.  The ideal temperature is between 91-96 degrees Celsius (195F-205F).  Closer to upper level is optimal, but never over.
  3.  Brew Ratio: This is the ratio in grams between the coffee and the water used.  The rule of thumb is 1:15-1:18, where 1:15 is stronger ratio since only 15g of water is used for every gram of coffee.  Note, this is only a rule of thumb as the other factors come into play, but it is a good starting point for your experimentation!
  4. Agitation (for steeping methods): The more you agitate or stir the coffee wile steeping, the more extraction you will get in a shorter time.  Since even coffee allowed to bloom first, will rise to the top of the water, agitation is needed for optimal extraction.  Blooming is the practice of adding just a little water initially and waiting for about 30 seconds before adding the rest of the water, allowing gasses trapped in the coffee to escape and the coffee to get saturated.  I recommend an initial gentle but firm agitation and then letting the coffee steep.
  5. Steeping time (for steeping methods):  You should allow optimal steeping time before you plunge if you are using a French press or filter out grounds in any other way.  If you are using a French Press, pour straight after plunging or decant, else extraction will continue.  The amount of time will vary from 4 minutes for French press to 24 hours for cold brew!
  6. Pouring technique (Pour over methods): A lot has been written on pour over technique.  The height, the number and duration of pours etc.  as it has the same effect as agitation in point 4 above.  I like to keep it simple.  After allowing for blooming as described before, I like to do around 5 pours to reach the desired ratio of water to my coffee, done in such a way where I do not let grounds go dry at any time and when I pour, I do it slowly and as stated in the Stumptown video, always aim for the dark spots, never for the light spots, in concentric circles.
  7. Pressure applied (Espresso and Aeropress)  Although most espresso machines have a fixed pressure, it does have an effect on extraction.  with Aeropress you can manage pressure your self and I have seen posts where people tray and achieve espresso from an Aeropress and going to lengths like creating a lever system to allow for increased pressure!  The general rule for the Aeropress is a gentle but firm, even pressure.
  8. Compaction (espresso): a lot, as always, have been said about pressure and how many pounds of pressure.  More important than this though will be to always tamp with a consistent pressure.  I apply pressure until the coffee grounds resist further compaction.  When you start tamping, the coffee will give way easily, but soon it start to resist.  I stop at my known point of resistance.  You should do the same and modify pressure if coffee either flows out like an open tap by increasing tamp pressure or fineness of the grind.  The opposite should apply if you get drop by drop espresso being extracted.  Compaction should of course leave you with a level bed of coffee.
  9. Distribution (espresso): The even distribution of the coffee in the portafilter before tamping will allow for optimal extraction.  Since water will always find the way of least resistance, we want to create even resistance to water penetration throughout.  There al lots of methods, but I use the ONA OCD distribution tool and swear by it!  Distribution is now less of an art, but I get super consistent distribution from using this tool.

An evening brewing black

Last week my wife and I attended an alternative brewing course at Vintage coffee.

Brewing0

It was a real eye opener for me who is mostly a cappuccino / sometimes espresso drinker.  Firstly all coffees are tasted black and secondly, coffees are tasted and allowed to cool down as you repeatedly taste them.

The evening started off with a quick informative talk on the history of coffee as well as the process from bean to cup.  I believe it is good to steep yourself in all things related to coffee.  Your appreciation and knowledge will help you enjoy your coffee more and more.

Brewing1

After the initial talk, we divided into three groups, each discussing and practicing a popular brewing method – French press, V60 pour over and the Aeropress.

First up was the V60 Pour over

Brewing2

At this demo, some principals were highlighted like the importance of weighing coffee and water, the correct water temperature, the correct grind and the timing of your brew.  Even though each method has its own special method, these principals remain the most important.  The pour-over probably produced the cleanest crisp coffee full of fruity notes backed up by a firm but not overpowering acidity.  It reminded me of a fruit juice in some respects.

Next up was the French press.

Brewing5

Since it filters through a metal and not a paper filter, it was more of a full bodied experience.  The difference to the taste and the way I used to make French press coffee before I knew the correct way, was very different.  I used to over-extract my coffee, with the guidelines in the French press blog, this should not happen.  See https://boxerbrew.com/2015/09/12/french-press/

Lastly, and perhaps my favourite, was the Aero Press

Brewing4

What made me enjoy this station most was the different ways one can make Aero press coffee, each with it’s distinct characteristics.  The use of an app to guide you through the process was awesome.  Unfortunately, the demonstrated app is only available in Apple’s store, but I found a close second in the android space named MisterBarista at https://play.google.com/store/apps/details?id=com.henleyb.aeropressbrewer&hl=en.  Although all the baristas was passionate about their method, I found the barista at this station particularly passionate and some interesting discussions was the result!

Brewing3

I can recommend this experience to anyone in the Pretoria, Johannesburg area and wish more coffee shops start to do this type of informal training.

Happy brewing and experimenting everyone!

Chemex – The sexy one

The Chemex is one of the most iconic, classic brewing methods.  When I first saw one I thought , “what a weird name” and “this looks like nothing”!  It grew on me though and now it is one of the brewing methods I would like to pursue.  You just have to look at the elegant lines of the Chemex and the wooden grip to fall in love with it.   I am crazy about the design having the filter holder as part of the eventual decanter.   I read somewhere that it is part of the MOMA permanent design collection.  Not sure what it is, but sound impressive!

kaboompics.com_Fresh morning coffee in the Chemex filter

The Chemex is a method in the pour-over category, unlike the French Press from last week which in the steeping category.  It will produce a very clean crisp coffee due to the thickness of the filter.  It maintains body and balanced floral notes in your coffee.  Her follows one method with one of Stumptown’s famous videos with their take at the end.


What you need

WhatYouNeed

  1. A eight cup Chemex and filter.  You can buy one for around R630-R900 ( $41.32  on Amazon)
  2. Coffee beans. Ideally, you should grind it yourself, but if you do not have a grinder, purchase a coarse ground to the texture of Kosher salt.
  3. A grinder.  A decent burr grinder will do, but not the whirly blade type grinder please.  If not, see point two.
  4. Water.  Filtered water since anything else could affect the taste.
  5. Timer.  I know I am walking a thin line here with the hard core coffee crowd, but since it’s not a science class, I am sure after timing things once or twice you won’t need it any more.
  6. Scale.  As with the timer, I believe that this is an aid for getting your brew right and not the rule, but with the Chemex it is quite important.
  7. Stirrer

Method

Hand drawing a black process diagam

  1. Grind and measure your coffee beforehand.  You can experiment and see recipes on internet, but start with 24 grams to 430 grams of water (1:17) and increase depending on required volume up to 700 grams.
  2. Get your water boiling.  Boil more water than is needed as you want to warm up your equipment.  Start your timer as boil ends.
  3. During first minute, place your filter in the Chemex with multiple folds to the spout.
  4. Use the boiled water to heat your Chemex and to “wash” your filter.  Drain this water.
  5. Add coffee into the filter.  With practice you should be ready for the next steps by the time you hit one minute
  6. At one minute, start your first pour.  This is to let the coffee bloom, by wetting the all the coffee without letting much coffee filter through – around double+ the weight of your coffee.  Stir gently to ensure there is no dry coffee.
  7. Wait 45 seconds, which should put you at around 1:45 from the boil of your kettle (45 seconds brew time).  It seems up to now that 45 second bloom time is fairly universal for all brewing methods apart from the obvious exceptions like Espresso..
  8. At 1:45 start a slow pour.  Aim for the dry spots and use this to gently agitate the grounds.  Fill up to around ten times the weight of your coffee – 240 grams in our case.
  9. A minute later at 2:45 start filling again.  Pour to the top and add water us coffee filters through.  Your aim is to reach 454 grams (Coffee weight included) just before your clock hits five minutes.
  10. At five minutes remove and discard filter, irrespective of how much water is in the filter.  You are aiming for pour time over volume.  Allowing all remaining coffee to filter through will lead to over extraction.

Don’ts

Donts

The biggest mistakes you can make are the following:

  1. Using boiling water. This will guarantee over extraction and the harsh bitter coffee that goes with it.  Waiting a minute for water to cool down is a good rule of thumb.
  2. Incorrect grind.  To fine will cause over extraction and possibly lower filter speed.
  3. Waiting for all coffee to filter through before removing filter will also lead to over extraction.

At first glance it seems complicated, but once you follow these easy steps, it should be simple enough that you do not even have to think about it.  If you use water off the boil and do a short pour and allow coffee to bloom for 45 seconds and pour remaining water and stop the brew at an appropriate time, you are just about there already!

As always: Remember, life is to short for bad coffee!

Here is an awesome video from the guys at Stumptown Coffee Roasters:

 

The Cafetière aka The French Press



French Press?  Sounds like the paparazzi, but it is probably one of the most accessible brewing methods.  In it’s simplest form it is a tubular container with a removable metal filter used to press down on the coffee.  This is the first in the series of blogs about alternative brewing methods from the steeping group.  This is the brewing methods that is the Jacuzzi group where coffee  chills in the water for a while.

It has had a bad rap, as producing harsh, murky or bitter coffee.  Here is a guideline to making good French press coffee. I searched wide and far on the wild, wild web and have distilled the best advice I could find. Following this guideline, should produce a full-bodied, robust coffee with intense flavors.


What you need

WhatYouNeed

  1. A French Press.  Any french press will do, but the best value for money is most likely a Bodum.
  2. Coffee beans. Ideally, you should grind it yourself, but if you do not have a grinder, purchase the coarsest coffee grind you can find.
  3. A grinder.  A decent burr grinder will do, but not the whirly blade type grinder please.  If not, see point two.
  4. Water.  Filtered water since anything else could affect the taste.
  5. Timer.  I know I am walking a thin line here with the hard core coffee crowd, but since it’s not a science class, I am sure after timing things once or twice you won’t need it any more.
  6. Scale.  As with the timer, I believe that this is an aid for getting your brew right and not the rule.

Method

Hand drawing a black process diagam

  1. Get your water boiling.  Boil more water than is needed as you want to warm up your press.
  2. Fill your French press.  This is to heat your press.
  3. Set your timer.  You have a relaxed one minute to prepare your coffee while your water is cooling slightly.
  4. Weigh (for starters) your coffee.  This is where you experiment, but start off on 1:10 ratio on weight between coffee and water.  This works out around a teaspoon (+) per cup.
  5. Grind your coffee.  Use a coarse grind setting. When you finish by pressing down on the filter, too little resistance will indicate too coarse grind and too much resistance will indicate too fine a grind.
  6. Empty the press.  At a minute, your boiled water would have cooled down a tad and will not lead to over extraction.
  7. Add the ground coffee to your French press.
  8. Pour water.  If you are using a scale, set to zero and pour ten times as much water by weight as the ground coffee you added.
  9. Stir.  At about forty five seconds from the time water was added, give a firm, but not over vigorous stir.  We don’t want to damage our press now, so use clean wooden or bamboo spoon.  This will release the trapped carbon dioxide from the coffee crust and most of the coffee should drop to the bottom.
  10. Press down to filter.  At about four minutes from the time water was added, press down slowly on the coffee.  Some people suggest breaking the crust and scooping it off before pressing down.
  11. Enjoy.  Use the coffee straight away or decant since over extraction may take place otherwise.

Don’ts

Donts

The biggest mistakes you can make are the following:

  1. Using boiling water. This will guarantee over extraction and the harsh bitter coffee that goes with it.
  2. Too fine grind. Once again, over extraction as well as a murkiness in the coffee.
  3. Too long time before pressing down on the coffee. At the risk of sounding like a broken record… over extraction.
  4. Not using the coffee straight away. I refuse to say it again, so I will only add that your coffee will cool down too much.

Hope this was not too much like school, but once you follow these easy steps, it should be simple enough that you do not even have to think about it.  Remember, life is to short for bad coffee!

Here is a cool video on the French Press from Stumptown Roasters.  Happy brewing!

Brewing Methods

How do I love thee?  Let me count the ways.  William Shakespeare

I was sent a post about alternative brewing methods by my daughter and that got me thinking….  I have seen a few alternative methods and have even seen videos on making your own.

So what methods are there?  What characteristics does each present?

Here is an informing layout I found on Pop Chart Lab’s site:

Confused much?  Let me start demystifying by briefly describing the method categories and how they relate to well-known methods.  In posts following this one, we will focus on the lesser known or alternative methods in more detail.  I am leaving out one category from the top since it is a combination of others.


Steeping


For this method, you will have a coarse ground coffee which will be steeped or soaked if you like in cold or hot water.  For cold water it could be for up to twelve hours.  No quick fix here.  Afterwards it is filtered and enjoyed in a number of ways.  Note: Cold brewed coffee will be sweeter due to its lower acidity but has higher levels of caffeine compared to some other brewing methods.  Most common example is the French press, but the Aeropress is gaining popularity.French press


Drip or pour over


Pour over coffee also starts with coarse ground coffee wich is placed in a filter, and a filter holder or ‘pour over dripper.’  Hot water is poured over the grounds and coffee filters through.  Best known example would be the filter machine.  Other manual examples are Chemex and V60.  For the Chemex and V60, the use of a gooseneck kettle is a must in order to have control over your pour.Filter machine


Pressure or vacuum


These are the same since vacuum is just reverse pressure.  For this method, hot water, is pushed through finely ground coffee under pressure.  The result will be a smaller volume, full-bodied coffee with firm acidity.  Best known example are the Espresso machine and the trusty Mokka pot, but vacume coffee makers are becoming more accessible. Espresso machine


In the coming weeks, we will go deeper down the rabbit hole.

Happy brewing