Good quality source product

Principle #1 of making good coffee: Using good quality source product

When playing around with hi-fi equipment, people always ask how much should I spend on speakers vs Amplifier and so on. The answer most of the time is to spend most of your funds on the source of your sound since no matter how much you spend on speakers, the sound can never get better than when leaving the source. The same goes with coffee – no matter how much you spend on your fancy espresso machine, it can never taste better that the coffee bean will allow you.

For this reason, I think principle#1 should be good source product. This is not only about the coffee, but also about the water and the milk you use. Only after this we will focus on Principle#2 of managing your extraction.

  1. The coffee
     Amongst the important source products, coffee is still the most important.  A friend of mine, being a little cash strapped, opted to buy some coffee at a bargain price elsewhere. He admitted afterwards that he will never buy coffee from “those people” ever again as it was horrible.  There are so many factors in the quality of the coffee, but here is the important ones in order of the process it follows:

    • The beans should be from a reputable farm using sustainable farming methods. The grade of coffee and harvesting principles can make a huge difference.
    • The processing method can affect the taste of the coffee. It can vary in fermentation method, washing method, drying method etc. some methods produces a better tasting coffee than others.
    • Freshness of coffee plays a role. Even though green coffee can be kept longer than roasted coffee, it is better fresher than not.
    • Roasting of the coffee can make or break the end product. This varies from coffee bean to coffee bean and some can be roasted to a darker roast, but in general, lighter roast will maintain more of the bean’s character where the roasting profile becomes more evident if roasting is dark, reducing some of the fruity character of the bean.
    • Age of roasted bean. Roasted coffee is best used within 2 weeks. There are a lot of debate on letting roasted coffee first rest and de-gas. I am of the school supporting this and prefer not to sell coffee before the first week after roasting.
    • Grinding size is discussed in principle#2 and not strictly about the bean, but the use of it instead. The quality grinder used is very important though, since a uniform grind size coupled with the ability to make minute changes in grind size will impact your enjoyment of the coffee in the end. It will be a shame if a coffee, lovingly produced and roasted is ruined by poor quality blade grinder.
  2. The WaterWhen you drink an Americano, 98% of your drink is water, so it is super important.  I am not an expert on the matter and there is not much I can say on the subject as it can become quite scientific.  What is important is to use good clean water that is well filtrated.  Filtration of solids not minerals, as some machines will not work properly when water is pure H2O.  this is because the sensors in some espresso machines will not be able to communicate with each other.  Reverse osmosis will also remove all minerals, leading to a flat tasting coffee not unlike too soft water.  Water ideally should have a PH of around  7 is neutral.  Ironically though, more acidic water is good for flavour, but bad for extraction where basic water is better for extraction but not so good for taste.  More importantly is the hardness of the water measured in dH for both Total hardness and Carbonated hardness.  we have been using borehole water with good PH, but have never done hardness tests.
  3. The MilkMost of the drinks we make are milk based drinks so the quality is super important.  we use super fresh full cream milk straight from the Willow Valley Dairy Farm having a natural sweet taste to it.   Other milk types are becoming more popular due to allergies and other datary reasons, but full cream milk produces the best latte art and taste.

 

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.