Practical guide – How to make a good coffee?
All preparations are based on the same principle: the extraction of coffee components, which are water-soluble. The water dissolves these components and produces a liquid solution, coffee. This transformation can be achieved through infusion (coffee in hot water), decoction (coffee heated in water), filtration called “leaching” (water passes through the coffee).
In reality, the latter is carried out in two ways: by pressure (Moka, espresso, piston, AeroPress®) or by gravitation (filter, cold infusion). Few machines do not combine several methods.
The French Press with piston, for example, combines infusion and filtration, while the siphons offer upward filtration by pressure, followed by infusion and finally downward filtration. Quite an art then!
THE 6 MECHANICAL VARIABLES OF ANY COFFEE PREPARATION
1. The coffee
The cup profiles vary according to the type of coffee (blend, single origin, single variety, altitude, etc.). Ethiopian varieties are aromatic and light, while Sumatra is deep and full. Coffee grind, density and solubility differ according to roasting: light, medium or dark. Thus, the more the roasting is pushed, the more soluble and voluminous the coffee, and the less it is necessary to dose and brew.
2. The size of the grind
Each preparation has its own grind. Basically, by refining, you increase the time it takes for water to pass through the coffee and the contact surface between the two. By doing so, you strengthen its extraction and privilege its power. On the contrary, by increasing the size of the grind, you favour under-extraction and risk developing astringency, acidity and lightness.
These effects can be mitigated by using the extraction time.
3. The extraction time
Each preparation has its own ideal time. The longer it is, the more power and possibly bitterness you develop. Not that the lightest components disappear, but the heaviest ones then dominate. The same is true for caffeine.
4. The coffee/water ratio
Each preparation requires its own dosage, but the more you “dose”, the more resistance, or material to dissolve, you offer to water. The dosage has a major effect on the medium and the extraction tail.
5. Water supply or flow
Faced with a granular mass, water creeps in and tries to create preferential channels. If you pour the water gently and evenly over the grinder, avoiding the edges of the filters, you force the water to pass through it in a harmonious way, thus fully extracting all the coffee. For espresso, it is advisable to fill and press the grind with the same concern for homogeneity.
6. Water, temperature and composition
Coffee consists, among other things, of oils and solid compounds that water is able to liquefy. The solvent power of water and its aggressiveness therefore depend on its temperature and minerality. By playing on the latter, you strengthen or reduce the extraction. Too many or too few minerals prevent compounds from being attracted to water.
For espresso and pressure, a seventh variable is to be taken into account: pressure. This is the force with which you constrain the contact between water and coffee. The higher the pressure, the more powerful and bitter your coffee is. The less it is, the more acidic, astringent and less concentrated your coffee is. So we play with the pressure profiles. In other preparations, similar effects can be created on turbulence, agitation and sequencing of the water flow.
THE 10 KEY POINTS OF ANY PREPARATION
1. Clean, easy-to-wash and neutral utensils: ceramic, stainless steel or glass. Avoid paper or cloth (filter).
2. Choose clean and balanced water: neutral pH, between 80 and 120mg of dry residue. The Volvic or Black Forest is suitable for gentle extraction, the Montcalm or Rosée des Près for espresso.
3. Always rinse and heat your instruments with freshly boiled water.
4. Choose a fresh coffee, less than four weeks old, ground per minute.
5. Always use the appropriate grind for your preparation.
6. Dose with a scale or, if not available, with a measuring spoon.
7. Use water between 90 and 95 °C maximum, depending on the coffee.
8. Adjust the coffee/water ratio according to your taste, roasting and tasting time.
9. Vary the extraction time according to your taste, the time, the roasting and the coffee.
10. Choose your coffee according to the moment, what you eat, your guests.
How to make a successful filter coffee?
First of all, get rid of your coffee machine. Because you didn’t make a mistake: the coffee you make with this device is not good and will never be good. Why is that so? Because a good coffee cannot be the result of an endless dripping of boiling water running into the centre of a coarse pile of lambda coffee.
Secondly, because it is impossible to access the flavour of a dish if parasitic, and often too powerful, aromas take precedence over others. I am thinking here of filter papers, which carry their taste of “paper”, even cardboard and chlorine, in your drink. Also plays the filter holder material, plastic, which quickly absorbs the most unpleasant odours and inexorably transmits them to any food with which it comes into contact.
Last reason: it is impossible for a drop of water falling in the center of a grind to have the ability to extract, in a uniform way, its substantial marrow. We could add an infinite number of other arguments, such as water quality, temperature, etc. But what is the point of continuing the enumeration?
Let’s look at how to do it.
THE FILTERS WE RECOMMEND
Let’s start by forgetting the plastic filter built into the coffee maker. You must make your choice according to two crucial points; the material and the shape. Choose filter holders that are melted or cast in an inert material, such as ceramic, stainless steel or some thermally shock-resistant plastics, such as Plexiglas. This will prevent you from giving your coffee the taste of everything you have drunk before….
The more you avoid contact with the paper, the better. Taste, even if only once, the water coming out of your paper filter will be enough to convince you to switch to the metal filter! The Kone, IMS or Yama brands are developing this market and offer stainless steel filters in various shapes and finishes, including gold for the rich aesthetes. Ceramic filters are also very convincing, except that they require a paper filter…
Distributed by the Japanese brand Hario, known as the V60, they provide impeccable support for your coffee, come in all sizes and fit directly on the cup. This type of filter has decisive qualities: its shape adapts to very thick grinds, the width.
The evacuation allows a better extraction and its fluted edges give the coffee the possibility to swell during the pre-brewing. The quality of the extraction depends on the shape of the filter.
The V60 is named after it because it is flared at 60°, while its competitor, Kalita, is much more vertical. Some filters are fluted for better pre-brewing. The filter market, the for over, is booming and many brands are boosting it. The same frenzy exists for paper filters: smooth, wavy or granular, white or brown, virgin or recycled, etc.
In recent years, some brands, particularly present in the 4th wave markets, have begun to invest in new generation electric coffee makers, often certified by specialty coffee associations such as SCAs: KitchenAid, MoccaMaster, Ratio, Buonavita, Wilfa etc. We can only recommend them if you need the comfort of electricity.
Beyond their differences and their sometimes random availability in France, these machines take into account the water temperature, its distribution and flow rate on ground coffee, as well as the quality of plastic materials. This is a first step. The most convincing one is the Wilfa, developed by the Norwegian Tim Wendelboe, but extremely fragile and sensitive to limescale. The Buonavita, with its perfectible design, comes in second place.
And already a new generation is emerging with a more refined design, precision and higher prices. This is the case with the Poppy Pour Over, which is a kind of all-automatic part of the electric coffee maker, since it produces coffee on demand, or the luxurious Trinity One, a high-precision multi-function machine.
Finally, if you are a professional or have a very large family, several brands of equipment now offer filter coffee makers of superior quality and high volume: Marco, Bravilor, Bunn etc…