I was a bit shocked a few days ago when I had a conversation with my partner about coffee. This is a discussion I have actually had with other individuals but I wasn’t expecting it from her.
The theme of the conversation was actually brought up when I told her I was preparing on composing a guide about coffee brewing and extraction.
“ Can you compose a whole piece on that? ” she asked.
“I might write an entire book on it” & rdquo; I replied.
“I thought it was simply pressing a button. Isn’t coffee quality more to do with how pricey your coffee maker is?”
This statement broke my heart a bit. My friend knows I am obsessed with coffee. The idea that she thought coffee making needed no talent at all was a tough pill to swallow. What does she believe I am using all of my time?
The regrettable reality is that the majority of people believe that coffee is just a push of the button. Any effort that goes into coffee making is jus lost time. I recollect another discussion with a fellow barista who mentioned to me he believed making espresso simply implied pressing a button, before he started working in the field.
However, I was grateful to my friend as I understood how crucial it was to write this piece on coffee extraction. So read on to discover what in fact goes into coffee making and what other skills are required to make delicious coffee, apart from impressive button pressing abilities!
What Is Extraction?
Coffee extraction is the procedure of dissolving tastes from coffee beans into water. It sounds incredibly straightforward in theory, I admit. Unfortunately, if we put raw, green coffee beans, (which are technically berries), into water, not much happens. Over time we have actually discovered that there are different aspects which increase the level of extraction, which means more coffee properties or Total Dissolved Solids (TDS) in the final cup of coffee.
The first of these factors is heat. Our forefathers really quickly understood 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 needed to leave the coffee beans soaking for much longer in order to get any sort of flavor at all in their brewed drink. This highlights the 2nd factor that influences coffee extraction: time. The longer the of time the coffee touches the water, the more caffeine and other soluble substances it draws out.
However, this original coffee beverage was still incredibly disappointing and tasted basically like the bitter plant that it was. Those ancient baristas needed to discover a way to increase the level of extraction from the coffee. Then one genius probably thought: if warm water draws more properties from the bean, then definitely it stands to reason that warming the beans over fire prior to 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 essential to coffee preparing as we understand it today. This opened an universe of coffee for those innovators. When we roast coffee we soften the internal cell structure of the coffee bean which permits us to draw out far more properties and flavors from the coffee bean.
This was the way coffee was likely extracted for years and years. Eventually, some smart coffee lover had the idea of crushing the roasted beans and preparing this ground coffee. Grinding coffee is the last main aspect which vastly increases the extraction of TDS from coffee beans. Grinding coffee increases the area of the coffee that is in contact with the water, therefore increasing extraction.
So there you have the three primary aspects that influence coffee extraction:
- Time
- Heat
- Grind size
We can break these elements down much further but for now let’s stick with these 3 headings. All elements in coffee brewing are interdependent. If we alter one factor, it affects the others and we have to adjust them too. I’ll discuss this in more detail a bit later on.
What are 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 too many dissolved solids in the drink, altering it from a scrumptious beverage to something bitter, awful and undrinkable. There is in truth a sweet spot for extracting coffee. In the early days of making coffee with raw green beans, the coffee was under extracted. Eventually, when all of the coffee brewing aspects were identified and included to the procedure, coffee began to be over extracted.
Clive coffee highlights how various coffee solids and flavors are drawn out in a particular order when preparing. Fats and acids are drawn out first, then sugars, and lastly plant fibers. The goal is to brew the coffee for enough time to get an ideal balance of these compounds in the cup, but not long enough to draw out the unwanted, bitter tastes.
Therefore, various levels of extraction outcome in different tastes in our coffee
. Under extraction If we don & rsquo; t apply enough of one or more of the extraction elements, we will get a coffee that is under extracted. For example, if the ground coffee isn & rsquo; t in contact with hot water for enough time, the coffee will be under extracted. Under extracted coffee tastes sour, and lacks sweetness, as the sugars have not yet been extracted to harmonize the oils and acidity.
Over extraction
If coffee is over extracted, nevertheless, it will taste bitter, due to too much of the bitter plant fibers being extracted from the coffee bean. Counter-intuitively, these plant fibers are the only properties that can be drawn out 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 perfect extraction point that we are going for will yield a beverage that is sweet, with proper 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 modern kinds of coffee brewing, heat, time and grind size are all factors that need to be considered when brewing each cup of coffee. In some cases one element can’t be adjusted for a particular reason for a particular preparing approach. Therefore, the other elements need to be adapted to harmonize with the set factor. Let & rsquo; s examine each one individually. Grind At a standard level, the finer the coffee is ground the more coffee is extracted. This is because of the increased surface area that touches with the water.
With every coffee brewing method, the grind size is picked based on a number of components.
These all need to be thought about 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 go through the filter.
With French press, the filter screen is much bigger than a paper coffee filter in basic French pots. This implies that the grind normally has to be coarser for French press than for filter coffee.
On the other hand, espresso has the additional factor of pressure during extraction, which speeds up the brewing process. The grind for that reason requires to be much finer for espresso due to the added force of the pressure forcing the water through a smaller sized area between the coffee grounds, at a quicker speed.
Finally, cold brew coffee is ground coarse to help the water leak quicker through the coffee grinds. Due to the much longer extraction time, fine ground coffee likewise tends to be over extracted when cold brewing.
Grind size can be adjusted minutely for all making methods in order to find that ideal extraction. However, all coffee making approaches have a standard grind size to follow. The grind size that enables ideal extraction for each method has been meticulously discovered over the period of many years.
Grind sizes for basic preparing methods are as follows:
- French press - Coarse
- Percolator - Coarse
- Cold brew - Coarse
- Drip - Medium grind size
- AeroPress - Fine
- Espresso - Extra fine
- Turkish coffee - Powder
Brewing Time
Similar to finer grind, longer brewing time equals higher extraction. Numerous making methods have actually a specific steeping time.
For instance, Drip coffee machines have a standard configured time to brew coffee. This suggests that the grind size and heat need to fit with the set extraction time in a drip coffee maker. 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 level are for that reason minutely calibrated in espresso preparation so that an espresso is pulled out within this time frame.
Cold brew doesn’t use heat in the brewing procedure at all. For this reason, cold brew needs a a lot longer time duration for extraction compared to heated coffee extraction. The longest time for many hot making methods is around 5 minutes. Cold brew takes between 12 and 24 hours to draw out appropriately, which is a significant variation.
Temperature level
Temperature (heat) is the last factor that increases the rate of extraction. The hotter the water, the quicker and higher the extraction. Therefore, if there is currently a greater level of extraction from a particular brewing technique due to other previously discussed variables, the water temperature doesn’t need to be as hot.
Espresso coffee has a great grind and a quick extraction time due to the addition of pressure. Therefore the water temperature level needs to be a little cooler than for other preparing approaches in order not to over extract it.
Drip coffee water needs to be hotter to encourage more of a reaction with the coffee, due to the lack of pressure.
Pour over coffee and French press coffee need to be hotter again. This however is primarily due to the exposure of the water to the air. The open air nature of these making methods causes the water to cool rapidly, which is counteracted by brewing with water at a higher temperature.
Roast
Although I didn’t include roasting as a factor that affects extraction, it is quite something that needs to be talked about here; so much so that it gets its own section. A coffee extraction procedure will always have to be adjusted for the type of coffee roast you are utilizing.
Similar to the extraction procedure, coffee beans can be roasted differently in order to promote greater or less extraction. The main factor that we are discussing when it concerns roast, is time.
The longer the coffee bean is roasted, the more properties are released from the bean and are for that reason drawn out much easier during coffee brewing.
This is the reason that dark roasted coffee is generally thought to be stronger than light roasted coffee. This belief was established by individuals who utilize the same brewing dish, regardless of roasting time. Coffee that is roasted for longer is extracted quicker, therefore it stands to factor that dark roasted coffee needs less of each brewing factor in order to extract efficiently. This suggests less time, coarser grind and cooler temperature levels. If brewing factors are adjusted to make up for a darker roast, dark roasted coffee can be prepared to be the like or weaker than a lightly roasted coffee, and vice versa.
So, hopefully, I’ve convinced you that making a good cup of coffee includes more than good quality equipment and slick thumbs for button pushing. With any luck, you have also discovered a little more about coffee preparation which will allow you to make your home brew that bit more scrumptious!
More knowledge on coffee extraction and coffee preparation: How to avoid bitter espresso