Making good coffee is an art. Baristas are the trained professionals of coffee making, but many coffee enthusiasts – besides enjoying great coffees from their favorite barista may be – also love to prepare their own coffee and like to play around a little with different techniques.
As common untrained person, one may refer to his or her prepared drink to be strong or weak. But what is that can clearly communicate the term strong or weak coffee? Does a coffee need to be dark to be strong or does it have to feel full-bodied too? What makes the coffee strong or weak and how many factors control that?
To understand the answers we may start from finding out what “flavors” or “notes” in a coffee are made up of.
A coffee bean holds within not just caffeine but also carbs, oils and some acids (hence the fruity notes). All these substances collectively give a coffee its distinctive aroma. They also contribute to its body or richness. When prepared as a drink, the caffeine, acids, sugars and oils, all from the coffee bean get extracted and dissolve in water. How rich or strong or dilute the drink is going to be depends upon mainly for how long the beans (roasted and grounded) are allowed to remain immersed in water.
But immersion time doesn’t solely determine the final drink. There are two more factors that are just as determining and are easy to play with; grind size and water.
While personal preferences vary everywhere, the SCA standards say best extraction percentages are 18% to 22%. To understand this percentage thing better; get this – some 28% of what’s present in a (roasted) coffee bean (by weight) is dissolvable in water. Rest is what seed is made up of and hence don’t go in the drink. If all of the soluble get extracted, brew is surely going to be a bitter one; means an over-extracted coffee.
An under-extracted coffee on the other hand feels sour or acidic. This means the first extracted flavor molecules are the acids or the fruity notes. This also indicates that sugars take longer to dissolve in water than acids. And the oils come last.
The best extracted coffee is determined by the very characteristics of a perfectly ripened fruit. The sweet n tangy smell that comes when sniffing a soft, plump, ripened fruit can be a perfect resemblance when referred towards the notes of a good extracted coffee. There is very balanced acidity along with a ripened fruit note.
Immersing the coffee grounds for longer is not going to produce the perfect cup of coffee alone. Depending upon the method of preparation; grind size matters very much. For pour over methods medium coarseness work best as the water find its way to flow through the coffee ground. For AeroPress finer grounds are fine. So with each method the grind size is different to work at best.
Water affects the brew in many ways. The quality of water is to matter the most when it comes to taste. Then is the ratio. For drip and pour over methods ideal ratio ranges from 1:15 – 1:18 (1g coffee per 15 – 18 g of water). For espresso however the ratio is about 1:2. This shouldn’t be very surprising as espresso is brewed at high pressure and very quickly.
Experimenting with different prep methods mixing and matching different factors can be an exciting journey. You’ll find your perfect ratios and time and then you’ll find new bag of coffee and the journey shall continue with new discoveries every time.