The unfortunate reality is that the majority of people believe that coffee is just a push of the button. I remember another conversation with a fellow barista who mentioned to me he thought making espresso just meant pressing a button, before he began working in the industry.
Nevertheless, I was grateful to my girlfriend as I realised how crucial it was to write this guide on coffee extraction. So continue reading to find what in fact goes into coffee making and what other abilities are required to make delicious coffee, apart from outstanding button pushing abilities!
Coffee extraction: what is it?
The evolution of coffee extraction
Coffee extraction is the process of dissolving tastes from coffee into water. It sounds exceptionally easy in theory, I grant you. Regrettably, if we put raw, green coffee beans into water, not much takes place. Gradually we have discovered that there are different elements which increase the level of extraction, which suggests more coffee properties or Overall Dissolved Solids (TDS) in the final cup of coffee.
The first of these aspects is heat. Our forefathers very quickly recognized that putting raw coffee beans in hot water created more of a reaction compared to soaking raw beans in cold water. They found that, if they didn’t heat the water, they required to leave the coffee beans soaking for a lot longer in order to get any sort of flavor at all in their brewed drink. This highlights the 2nd aspect that influences coffee extraction: time. The longer the of time the coffee is in contact with water, the more soluble compounds it draws out.
Nevertheless, this original coffee beverage was still exceptionally unsatisfactory and tasted basically like the bitter plant that it was. Those ancient baristas needed to discover a method to increase the level of extraction from the coffee. Then one genius most likely believed: if warm water draws more properties from the bean, then certainly it stands to factor that heating up the beans over fire before putting them in hot water might release more of the coffee bean properties?
Eureka! Cooking or roasting the coffee beans before boiling them in water was the key to coffee preparing as we understand it today. This unlocked an universe of coffee for those pioneers. When we roast coffee we soften the internal cell structure of the coffee bean which allows us to draw out much more properties and flavors from the coffee bean.
This was the way coffee was most likely obtained for many years and years. Ultimately, some smart coffee lover had the idea of squashing the roasted beans and brewing this ground coffee. Grinding coffee is the last main aspect which significantly increases the extraction of TDS from coffee beans. Grinding coffee increases the area of the coffee that is in contact with the water, thus increasing extraction.
So there you have the 3 main aspects that influence coffee extraction:
- Time
- Heat
- Grind size
We can break these factors down much further but for now let’s stick with these 3 headings. All elements in coffee preparation are interlinked. If we alter one element, it impacts the others and we need to change them as well. I’ll talk about this in more detail a bit later.
Over-extraction and under-extraction
Primal coffee drinkers became so proficient at drawing out the coffee properties that they started going too far. They realized that it was possible to have a lot of dissolved solids in the beverage, altering it from a scrumptious drink to something bitter, horrible and undrinkable. There is in fact a sweet spot for extracting coffee. In the early days of brewing coffee with raw green beans, the coffee was under extracted. Eventually, when all of the coffee making aspects were discovered and included to the procedure, coffee began to be over drawn out.
Clive coffee highlights how different coffee solids and tastes are extracted in a particular order when preparing. Fats and acids are drawn out first, then sugars, and finally plant fibers. The objective is to brew the coffee for long enough to get an ideal balance of these substances in the cup, but not long enough to extract the unwanted, bitter compounds.
For that reason, various levels of extraction lead to various tastes in our coffee
. Under extraction If we don & rsquo; t apply enough of one or more of the extraction aspects, we will get a coffee that is under extracted. For example, if the ground coffee isn & rsquo; t in contact with boiling water for long enough, the coffee will be under extracted. Under extracted coffee tastes sour, salty and lacks sweetness, as the sugars have actually not yet been extracted to harmonize the oils and acidity.
Over extraction
If coffee is over extracted, however, it will taste bitter, due to too many of the bitter plant fibers being extracted from the beans. Counter-intuitively, these plant fibres are the only properties that can be extracted from raw coffee beans without the addition of heat, which is why green coffee beans taste extremely bitter and unpalatable.
The extraction sweet spot
That best extraction point that we are going for will yield a beverage that is sweet, with suitable level of acidity and a long finish ; the finish being the instant feeling that we experience after taking a sip of the coffee.
The extraction process
So, for all contemporary kinds of coffee brewing, heat, time and grind size are all factors that need to be thought about when preparing each cup of coffee. Sometimes one element can’t be changed for a specific reason for a particular preparing method. Therefore, the other elements have to be adjusted to fit in with the set aspect. Let & rsquo; s evaluate each one separately. Grind At a fundamental level, the finer the coffee is ground the more coffee is extracted. This is because of the increased surface area that is in contact with the water.
With every coffee preparing method, the grind size is chosen based on a variety of elements.
These all need to be considered when considering the grind for a brew.
With drip coffee, the grind can’t be too fine or else the water would take too long to pass through the filter.
With French press, the filter screen is much bigger than a paper coffee filter in basic French pots. This means that the grind usually needs to be coarser for French press than for filter coffee.
On the other hand, espresso has the added element of pressure throughout preparation, which further accelerates the preparation process. The grind therefore needs to be much finer for espresso due to the included force of the pressure forcing the water through a smaller space in between the coffee premises, at a quicker speed.
Finally, cold brew coffee is ground coarse to help the water drip faster through the coffee grinds. Due to the a lot longer extraction time, fine ground coffee likewise tends to be over drawn out when cold brewing.
Grind size can be adjusted minutely for all preparing methods in order to find that perfect extraction. Nevertheless, all coffee making methods have a standard grind size to follow. The grind size that allows for ideal extraction for each technique has actually been painstakingly experienced over the duration of many years.
Grind sizes for standard brewing approaches are as follows:
- Cold brew - Coarse
- French press - Coarse
- Drip - Medium grind size
- AeroPress - Fine
- Espresso - Extra fine
- Turkish coffee - Powder
Brewing Time
As with finer grind, longer extraction times equates to higher extraction. A number of preparing techniques have a particular brewing time.
For instance, Drip coffee machines have a standard set time that they take to brew coffee. This means that the grind size and heat have to fit with the set extraction time in a drip coffee machine. In drip coffee this equates to a medium grind size and water that is almost at boiling point.
The perfect time for standard espresso extraction is between 20 and 30 seconds. The grind size and the temperature are therefore minutely calibrated in espresso preparation so that an espresso is extracted within this time frame.
Cold brew doesn’t apply heat in the preparing process at all. For this reason, cold brew needs a a lot longer period for extraction compared to hot coffee extraction. The longest time for most hot brewing approaches is around five minutes. Cold brew takes between 12 and 24 hr to draw out effectively, which is quite a difference.
Temperature level
Temperature (heat) is the last factor that increases the rate of extraction. The hotter the water, the quicker and higher the extraction. For that reason, if there is already a higher level of extraction from a particular preparation technique due to other formerly pointed out factors, the water temperature level doesn’t need to be as hot.
Espresso coffee has a fine grind and a quick extraction time due to the addition of pressure. Therefore the water temperature level requires to be a little cooler than for other brewing methods in order not to over extract it.
Filter coffee water requires to be hotter to encourage more of a response with the coffee, due to the absence of pressure.
Pour over coffee and French press coffee need to be hotter again. This however is mainly due to the direct exposure of the water to the air. The open air nature of these making techniques causes the water to cool quickly, which is combated by brewing with water at a higher temperature.
Roast
Although I didn’t include roasting as a factor that influences extraction, it is quite something that requires to be gone over here; so much so that it gets its own section. A coffee extraction recipe will always have to be adjusted for the kind of coffee roast you are using.
Similar to the actual extraction process, coffee beans can be roasted differently in order to promote higher or less extraction. The main aspect that we are talking about when it pertains to roast, is time.
The longer the coffee bean is roasted, the more properties are released from the bean and are for that reason extracted simpler throughout brewing.
This is the reason that dark roasted coffee is typically thought to be stronger than light roasted coffee. This belief was developed by individuals who utilize the same preparing recipe, despite roasting time. Coffee that is roasted for longer is extracted quicker, therefore it stands to reason that dark roasted coffee needs less of each brewing factor in order to extract efficiently. This implies less time, coarser grind and cooler temperatures. If preparing aspects are adjusted to compensate for a darker roast, dark roasted coffee can be prepared to be the exact same as or weaker than a lightly roasted coffee, and vice versa.
So, hopefully, I’ve convinced you that making an excellent cup of coffee includes more than great quality equipment and slick thumbs for button pushing. With any luck, you have likewise discovered a little bit more about coffee preparation which will allow you to make your home brew that bit more delicious!
Other information on extraction and coffee making: What is the best grind for strong coffee