What is Coffee – Coffee Facts, Statistics and Effects of Coffee on Health

Coffee Cherry
Photo Credit: FCRebelo, Wikimedia Commons

What is Coffee and Why Do We Love It?

Do we love coffee because we are addicted to it, or because coffee’s chemical makeup makes sense for our body? Coffee is not a pleasant tasting experience for almost anybody on the first try. Many people just hate the taste. However, coffee contains a lot of antioxidants, and caffeine, the much needed “pick-me-up”. Could this be the reason we end up “loving it”? Or is just the addiction?

Coffee, the beverage, is the result of brewing the roasted and ground coffee beans.

Coffee beans are the pits of the coffee tree fruit.

The coffee tree, (Coffea), is an evergreen, a small tree or a shrub, that grows in the tropical climate region. The coffee beans are actually not beans, they are the pits removed from the coffee cherries.
Coffee is a natural stimulant creating a mild addiction and is associated with many health benefits. However, the abuse of coffee can result in many health problems.
The beverage brewed from the coffee beans is one of the most appreciated in the world and it makes an important export percentage of many countries.
Caffeine is a coffee extract and it is very widely used in the pharmaceutical industry.

Brief Coffee History

Folk tales place the discovery of coffee around 850 AD in Ethiopia, where Kaldi, a goat herder, found his goats to be very energetic when they grazed on the bright red berries of a certain bush.

However, the earliest evidence of coffee as a beverage appears in the present Yemen territory in the 15th century in Sufi shrines. Coffee seeds were roasted and brewed similarly to how is prepared today.

The genus coffea was first described in the 18th century by the Carl Linnaeus, a Swedish botanist. Linnaeus also described Coffea Arabica in his Species Plantarum in 1753.

Coffee was introduced to Europe in the 17th century, and coffeehouses quickly became popular.

During the second half of the 19th century, coffee production in South America grew at a faster rate, production fueled by the fast pace consumption in developed countries. The United States had by far the fastest consumption growth.

The late 19th and early 20th centuries brought major improvements in industrial roasting and grinding. Packaging evolved in order to prolong coffee shelf life, and vacuum-sealed packaging and nitrogen flush during packaging were invented. The 20th century also brought green bean decaffeination.

In the 21st century, an old debate on the health benefits and risks of coffee was solved. Coffee is good for us, and coffee consumption was associated with a lower risk of death, in a research study done by NIH.

Coffee Definition

Yellow Bourbon Coffee Cherry
Photo By Fernando Rebêlo via Wikimedia Commons

Coffee Brewing Definition

Coffee is a brewed drink obtained by extracting in water the soluble components from the roasted pits of the coffee cherry. Coffee is a beverage with a variable percentage of caffeine, and a specific aroma and taste.
The aroma and taste vary with the Coffea genus, the extraction method, the quality of the coffee beans, and the concentration of the final beverage. The extraction methods are loosely split into two categories: cold extraction or cold brew, and hot extraction, which includes low-pressure extraction, and high-pressure extraction, in the case of espresso.

What Is Caffeine?

Caffeine is a white bitter, crystalline substance, extracted from different plants, the most popular one is coffee. Caffeine is toxic in very large doses, but in normal doses has high therapeutic values. However, caffeine creates both physical and mental dependence. Caffeine is a psychoactive drug, one of the fewest unregulated ones.
Caffeine is has a host of side effects even in low doses. And what is more interesting, is that people have different degrees of tolerance to caffeine. Some can consume huge amounts in comparison to others. Even the same person can tolerate caffeine differently, depending on the health, genetics, daily consumption, etc…
Those that can consume huge amounts of caffeine without being affected, are most likely the carriers of special gene, that allows them to metabolize caffeine better. So don’t feel bad to refuse an invitation to a coffee in the afternoon.
Some of the side effects of caffeine are:  insomnia, headaches, restlessness and shakiness, rapid or abnormal heart rhythm, dizziness, dehydration, anxiety, dependency.

Coffee Nutrition Facts

Coffee&Health.org , black coffee does not contain significant quantities of fat, carbohydrates, or protein. This means coffee has a very low-calorie content, and it is close to 0 calories per cup (2 calories, to be more precise). However, things get out of control when we add sugar, cream, or even skimmed milk.

Even though coffee does not contain any macronutrients , it contains some micronutrients, however, it is not particularly a rich source of those either. It contains:

  • Magnesium: 8mg/100ml
  • Potassium: 92mg/100ml
  • Riboflavin: 0.01mg/100ml
  • Niacin: 0.7mg/100ml
  • Manganese: 0.05mg/100ml

As we see, the most notable micronutrients are some B vitamins and the magnesium. More coffee nutrition data here Some of these numbers can be affected drastically by the water used to brew it since calcium and magnesium can vary a lot in different water sources.

Most of the health benefits of coffee don’t come from the nutritional value, though. These health benefits are attributed to caffeine and the high amount of antioxidants. According to Authority Nutrition , coffee is maybe the most important source of antioxidants in our modern diet.

Coffee Health Benefits

We wrote a detailed article where we show if coffee is good for you or not. We list there all of the health benefits of coffee, but as a quick reminder, here is short list:

  • Coffee prevents Aging
  • Prevents Dementia, and Parkinson’s disease.
  • Reduces the risk of Type 2 diabetes
  • It is a stimulant
  • Lowers the risk of liver cancer, and fatty liver disease.
  • Prevents various other diseases such as liver cirrhosis, kidney stones, gallstones.
  • And the most interesting one, (at least in my opinion), coffee can improve cognitive functions, and prevent cognitive decline. Many research studies have shown that coffee improves many aspects of brain function, such as memory, mood, vigilance, energy levels, reaction times, and more.
  • Lowers the risk of non-melanoma skin cancer according to a meta-analysis, published in the European Journal of Nutrition.

The explanation for the association between coffee consumption and lower rates of cardiovascular disease and diabetes is though to be related to chlorogenic acid and other antioxidants and phytochemicals in coffee, although science is not entirely sure about this.

The Dangers of Too Much Coffee

Turkish coffee cups in Uganda
PhotoCredit sarahemcc

Coffee is great for us, but as anything else, the dose makes the poison. Abuse can turn a wonderful beverage into a poison. Let’s go through some of dangers of consuming too much coffee.

  • Coffee is addictive
    Caffeine is a mildly addictive substance and people who stop its consumption experience some withdrawal effects. Coffee withdrawal can result in serious headaches that can last up to a week.
  • Coffee Abuse is dangerous
    Too much caffeine can produce restlessness, nausea, headache, tense muscles and sleep problems.
  • Coffee may aggravate ulcer problems and cause heartburns.
  • Sleep Problems
    The consumption of coffee afternoon may affect sleep and cause insomnia. Young people should never drink coffee. Regular coffee consumption could be as bad as alcohol for young people, but because the effects of coffee are not immediate, we usually consider it less dangerous.
  • Coffee and Skin Problems
    For many people, coffee will create skin problems. It looks like autoimmune skin disorders are in direct relation to the amount of coffee consumption. The substantial dehydration caused by coffee will also cause skin problems.
  • It can Raise Blood Pressure
    In the short term, it can raise blood pressure, making arteries stiffer, and can increase levels of homocysteine, insulin, and possibly cholesterol. (health.harvard.edu) What this means is that if you are affected by one of the issues above, you need to avoid coffee.
  • Coffee for kids and teens
    A high intake of caffeine in adolescence can lead to permanent changes in the brain, which can increase the risk of of anxiety-related conditions in adulthood.
  • Coffee – Calorie Count
    Coffee alone has only 2 calories per serving. However, when we add creamer and sugar that can change a lot the calorie count. The coffee beverages you get at the coffee chains, (Starbucks, Dunkin’ Donuts, etc…) can go up to 380 calories, depending on the size. I admit I add sugar to my coffee, but I stay away from the Starbucks mixes.
  • Caffeine and Calcium Absorption
    Caffeine interferes with the mechanism of Calcium absorption, leading to osteoporosis. If you are at risk to develop osteoporosis, avoid coffee consumption.
  • Coffee and Drugs
    Coffee can interact with other drugs and possibly potentiate them. For instance, coffee and fluoxetine together can cause side effects such as anxiousness, agitation, and extreme alertness. People who drink coffee and take Prozac reported unusual coffee cravings.
  • Caffeinism
    Caffeinism is a condition associated with the consumption of large amounts of caffeine. The symptoms of caffeinism are dependency, nervousness, irritability, insomnia, restlessness, heart palpitations, and headaches.
  • Pregnant Women
    Moderate coffee consumption is deemed safe for pregnant women. However, caution is recommended, especially because tolerance can vary a lot. There is also concern for miscarriage and and for decreased birth weight in association with coffee.
In our article dedicated on coffee impact our health, “Is Coffee Good For You?“, we talk about the danger of coffee more detailed. Take a look at that article if you need more info.

Caffeine can affect all of our body’s systems: nervous, circulatory, respiratory, digestive, excretory, endocrine, etc… Abusing coffee will put in overdrive one or more of these systems, causing illness. Make sure you understand all the pros and cons of drinking coffee.

Your Brain On Coffee

Decaffeinated Coffee

Since caffeine is only in part responsible for the benefic effects of coffee, and since caffeine is the responsible compound for the the side effects, people started to decaffeinate coffee. There are many ways to decaffeinate coffee, some methods are surrounded by controversy.

Some, have gone as far as labeling decaf coffee as dangerous. I don’t agree with the article, I think the article it’s just an exaggeration, but I included it just as a reference.

Decaffeinated coffee is healthy, and in fact is the better option for those sensitive to caffeine, or as a healthier alternative in the afternoon.

Coffee Production


Coffee plants are cultivated in over 70 countries, in a zone South and North of the the equator, between the tropics, known as the bean belt. The primary coffee growing regions are Central and South America, Southeast Asia, the Indian subcontinent, and Africa.

Additionally, the coffee plant requires higher altitude for growing, where the cooler temperatures delay the growth cycle for a longer maturation. For this reason most of the coffee plantations are found at altitudes between 2500 and 7500 feet.


After coffee is harvested, a a complex process of processing begins, in order to remove the pit from the coffee cherry. The coffee pits are what we call bens.

During processing, workers remove cherry pulp, skin, and a parchment that surrounds the bean.

Processing is particularly important because it will affect the beans’ flavor and aroma.

  • Washed coffees are de-pulped, and then are fermented for about 24 hors to allow the mucilage to break down, and then washed with fresh water. Washed coffee processing is also called wet processing.
  • Natural processed coffees, are allowed to slowly dry first, and then the fruit is stripped away.
  • Honey processing is a processing method where the cherry is removed immediately after harvesting, but some of the fruit pulp remains on the beans during the drying process.

Natural and honeyed coffees tend to be a bit more fruity, and sweeter than the washed counterparts, which tend to reveal more of the terroir, unadulterated by the fruit sweetness.

Coffee Types, Arabica vs Robusta

green coffee arabica vs robusta
Pictures by FCRebelo, Wikimedia Commons

Varieties of Coffee

  • The coffee type and roast are extremely important for the final product in our cups.
  • The most common types of coffee are arabica and Robusta.
  • Arabica is the most commonly used type of coffee with more than 80% of the total coffee production.
  • Robusta is the second most used coffee variety and it is well known for its resistance to pests and cheaper production price.
  • Other less popular varieties of coffee include coffee Liberica, Cameroonian coffee, Congo coffee, Sierra Leonean coffee, and Bengal coffee.

Arabica vs Robusta

  • Arabica is more acid than Robusta and has more flavor. Coffea Canephora (Robusta) has a stronger bitterness very common in French and Italian coffee preparation and contains more caffeine.
  • Coffea arabica, has a lot of varieties depending on the country of origin, the geographical conditions and other more subtle factors.
  • Arabica coffee is preferred, because, typically, Robusta coffees have a bitter/rubbery flavor. However, good Robustas are fantastic additions to any coffee, (no rubbery taste), but are more expensive.
  • Many times espresso blends contain Robusta beans, because they produce more crema. A decent ratio between the two varieties, for balanced espresso could contain 65% Arabica and 35% Robusta. However, one should experience various blending ratios. My preference is around 75% Arabica, and 25% Robusta.

Brewing Coffee

Pour Over Coffee Maker Melita
Brewing Pour Over Coffee

Brewing coffee can be a complex task that requires a deep knowledge of coffee, coffee roast, and grind.

There are full-time jobs dedicated to preparing and serving coffee. The employee who makes and serves coffee is called a barista. Brewing coffee involves knowledge about roasting, grinding, preserving coffee, as well as combining ingredients for coffee recipes.

Coffee can be brewed in many ways, the most popular brewing methods are:

Specially designed devices push steam through coffee grinds at a given pressure. The greatest amount of aromatic oils is kept and the coffee does not contain as much caffeine as other methods.

French press
The French press uses a metal filter that will filter less of the aromatic oils so appreciated by coffee snobs like me. (Note that the coffee oils are in fact the compounds responsible for raising cholesterol.)

Turkish, Greek, Eastern European, (Turkish variants)
When preparing Turkish coffee the beans are ground to a fine powder and infused or boiled to low temperatures. The aromatic oils are kept.

Drip Coffee
It is the most popular brewing method. Uses a paper filter which holds the coffee grinds. Water passes through coffee and paper. More caffeine than other methods but the coffee is very clear, less aromas and flavors.

Cold brew
This type of coffee is prepared using a cold infusion of the coffee grinds. Cold brew coffee has more flavors, less acidity, and less caffeine.

CaPhe, (Vietnamese)
Uses a device similar to French press. The coffee is ground very fine. A lot of aromas are kept.

Single serve brew
It is really a special type of coffee because it uses a pump to run steam through coffee grinds but is not an espresso either. Depending on the manufacturer, the brewer can give you a coffee that ranges from drip coffee to espresso.

You also check our detailed coffee brewing guide for more info.

Coffee Roast

coffee beans very dark roastoffee roasting is one of the most important steps in coffee production. The roasting is changing the chemical properties of the beans so they have the proper taste and aroma. Without roasting the coffee is bland without any flavor and taste. Various degrees of roasting permit the obtaining of different tastes and flavors. Some people prefer to buy green coffee and roast it at home for a better control of the taste and maximum freshness. The green beans are more stable than the roasted ones so the coffee won’t lose aroma.
Unroasted coffee cannot be brewed using conventional methods, because the compounds that give coffee the specific taste and aroma, are not soluble, when the beans are green. Roasted coffee beans have the cell structure changed in such way that soluble compounds in the beans are easy to extract.
Here are the major roast degrees:

  • Light roast: – Cinnamon Roast, New England Roast
  • Medium roast: – American Roast, City Roast, Full City Roast
  • Full roast: – Vienna Roast, (one of my ex-favorites)
  • Double roast: – French Roast, Italian Roast, Spanish or Turkish Roast, and Spanish roast, (in the photo), is the darkest coffee roast possible.

A note on the roast names: these are marketing names, typically used in North America. What we buy in North America as Italian roast, might be very different from what we buy in Europe as Italian coffee. Further more, Italians have different tastes when it comes to roasting their coffee. The South prefers darker roasts, while the North prefers lighter roasts.

Dark Roast vs Light Roast

Various coffee bean roasts
Photo Credit Jurgen Howaldt

Which Roast is the Best?

The more we roast the beans the less of the original flavor remains, being replaced by the specific taste and flavor of the roast.

Coffee roast and type is an acquired taste, I changed coffee type a few times in my life and every time I had problems adapting. There is no perfect roast because we all have our preferences.

Some types of coffee will “demand” less roasting so they will retain more of their personality. Some types of brewing though will require a special type of roasting. For example Turkish coffee and espresso need darker roasts, house blends, (melange maison), are a medium roast so that we keep some of the original coffee flavors.

I drank the whole range of roasted coffee and enjoyed all of the types. The only remark I have here is that the very dark roast types lose all of their personality and become bitter. At higher temperatures and prolonged exposure to heat, the sugar in beans caramelizes and eventually disappears, being transformed into charcoal.

This is how the coffee gets its extra bitterness. Sometimes, this is a procedure to cover the bad taste of low quality coffee. By burning the coffee beans, all of the original aromas are lost. There is also some caffeine loss, contrary to the popular opinion that dark roast beans offer a stronger coffee. However, the difference is minimal, so most of us wouldn’t even note the difference.

What you didn't know about coffee: Asher Yaron at TEDxUbud

Coffee Grinding

Coffee grinding is a very important aspect of coffee preparation. The grinding will influence the taste, the flavor, and the coffee strength, (the amount of extracted caffeine).
For instance, an espresso grind is somewhere between the Turkish – the finest grind – and the drip grind. Turkish brew needs a very fine ground coffee so that it will reveal all of the coffee flavors and sink easily to the bottom of the cup.

Traditionally, Turkish coffee is served unfiltered to preserve the maximum of the aromatic oils that impart the flavor.
Grinding is one of the latest steps in coffee preparation. After grinding, there is a lot more contact surface with the air, (oxygen) so there is a larger oxidizing surface; that’s why grinding should be done seconds just before brewing.

Coffee Beans – Where Do They Come From

What we refer to as a coffee bean, is not a bean, it is actually the pit of the coffee cherry. The coffee cherry is the fruit of a small tree or shrub, depending on the variety of the coffea genus. The cherries are picked when they are ripe, and then the seeds are separated. Some roasters will let the fruit dry on the seed, some will remove the fruit immediately. By letting the fruit more on the seeds more flavor is preserved, however, the separation process is more complicated.

There are various techniques to process the beans. The beans are dried, and in this state, they are what we call green coffee beans. The green beans are then transported to the roasting houses. The unroasted beans, (green), are very stable and they will not lose flavor. Once roasted though, the beans start to lose flavor each time they come in contact with the air. This is why an airtight recipient is the best way to keep coffee fresh.

What is the reason you love coffee?

Is it the whole experience, or is it just the caffeine?
Is coffee a reason to socialize for you?
Or is it just a need for something to wake you up in the morning?
Share your thoughts about coffee.

Photo of author

Dorian Bodnariuc

My name is Dorian and I am a former barista. I consume coffee in any form, as a beverage, in savory recipes and desserts. My favorite caffeinated beverage is the espresso. I love to share my coffee brewing knowledge and my geeky coffee research. This blog is one of the places I write about coffee. More about Dorian... If you want to learn more about this site and how I started it, check our About Me page, where I explain all about it.