Insight

How is Coffee Decaffeinated?

One of the reasons why people enjoy drinking coffee is the stimulatory effect of the caffeine it contains. Consuming caffeine is a great way to boost your mental alertness and bolster your energy levels. However, some people prefer to avoid caffeine, usually for health reasons or because they find its effects unpleasant.

If you enjoy the taste of coffee but don’t like caffeine, you can always try decaffeinated coffee.

In this post, we will share everything you need to know about decaffeinated coffee, including the answers to common questions such as “what is decaffeinated coffee?” and “how is decaf coffee made?”.

Let’s dive in!

Firstly, what is decaffeinated coffee?

Decaffeinated coffee, also referred to as ‘Decaf’, is simply coffee that has had most of its caffeine removed. This can be accomplished using a variety of processes (more on that below). Each process aims to eliminate most of the caffeine within the green coffee bean while retaining the important molecules that give coffee its great flavour and aroma.

Interestingly, the amount of caffeine that needs to be removed for a coffee bean to be called ‘decaffeinated’ varies between countries. In the United States, the USDA stipulates that decaf coffee should have at least 97% of it’s caffeine removed.

In the European Union, a coffee product can only be considered decaffeinated if at least 99.9% of its caffeine content is removed. That would be about 0.1 mg of caffeine in your average cup of decaffeinated coffee.

Does decaf coffee have caffeine?

Yes, it does. It is important to understand that decaffeination never removes all of the caffeine in the coffee bean. This is because stripping all of the caffeine from the bean would also remove most of the valuable compounds that give the bean it’s wonderful flavour and aroma.

In other words, if this was done, you’d end up with a bean that tastes extremely bland!

How much caffeine is in decaffeinated coffee?

Your typical cup of coffee is about 236 ml and will contain about 120mg of caffeine. If you are drinking decaf in the EU, you can expect there to be less than 0.1 mg of caffeine in your cup. If you were to drink decaf in the United States, at least 97% of the caffeine has been removed, so it will contain 3.6 grams of caffeine or less. If you are trying to avoid caffeine for a medical reason, it’s important to remember that decaf will still contain some caffeine.

So, how is coffee decaffeinated?

Coffee can be decaffeinated using several methods. However, all of these methods will alter the chemical structure of the ‘green’ coffee bean, before it has been roasted. The main goal of decaffeination is to remove the caffeine from the coffee bean while retaining the molecular components which give the bean its flavour.

Decaffeination is a difficult process to get right because coffee beans have a complex structure, with over 1,000 chemicals contributing to the bean’s flavour and aroma. If the process is too harsh and eliminates or alters too many of those chemicals, the resulting coffee would taste horrible!

But how are coffee beans decaffeinated? Well there are several methods:

Indirect-solvent process

This is a very common technique for decaffeination in Europe. The green coffee beans are first soaked in very hot water for several hours. This extracts most of the bean’s caffeine content along with the compounds that give the beans flavour.

The green beans are removed and the water is transferred to another tank. The water is treated with methylene chloride or ethyl acetate, which are chemicals that will bond with caffeine molecules.

The resulting mixture can then be heated to remove both the solvent and the caffeine molecules via evaporation. The beans are then re-introduced to re-absorb the oils and chemicals that are responsible for flavouring the coffee beans.

The water is re-used in subsequent batches of beans to get more flavour into each batch. Eventually an equilibrium is reached, where the beans have most of the flavour of coffee, without the caffeine.

Direct-solvent process

The green coffee beans are steamed for about 30 minutes to open their pores, then exposed to a solvent which is usually methylene dichloride or ethyl acetate. They are washed in the solvent for about 10 hours to extract any caffeine. The solvent is drained and the beans are washed repeatedly to remove any traces of solvent.

The ‘Swiss Water’ process

This is also a chemical-free decaffeination method that was first developed in Switzerland in 1933. It was made commercially available in the 1980’s by a company named Coffex. This method uses solubility and osmosis to extract caffeine from the beans.

The Swiss water process starts by soaking the beans in very hot water to dissolve the caffeine. The water is extracted and passed through an activated charcoal filter. This filter captures the relatively large caffeine molecules while allowing the smaller molecules and oils that give coffee its flavour to pass through.

This results in coffee beans with no flavour and a caffeine-free coffee-flavoured water solution in a tank. The first batch of flavourless beans are discarded and the coffee-flavoured water is used to remove the caffeine from a new batch of beans.

Because the water already contains the oils and molecules that provide coffee with flavour, the oils and molecules from the second batch of beans cannot dissolve as effectively. This means the caffeine will be extracted from the second batch of beans, but they retain most of their flavour.

Decaf coffee that has been produced using this method will usually be labeled “Swiss Water” decaf. It is the method used for most organic coffee beans because it doesn’t involve chemicals.

CO2 (Carbon Dioxide) Method

This is the newest method for decaffeination of coffee beans. The CO2 method was developed by Dr. Kurt Zosel, a researcher working at the Max Planck Institute. This process uses CO2 to remove caffeine from green coffee beans instead of a chemical solvent.

The green coffee beans are soaked in water and placed in a stainless steel container. The container is sealed and liquid CO2 is forced at high pressure to extract the caffeine from the beans while leaving the flavour molecules behind. The caffeine rich liquid CO2 is pumped into another container where the air pressure is released, causing it to become a gas once more, leaving the caffeine molecules behind. The gas is then pumped back into the first vessel, ready for the next batch of beans.

So there you have it, we hope you found our article on decaffeinated coffee useful. You’ll find more articles on coffee on our blog.

And don’t forget to check out our ‘Roaster’s Choice’ decaf coffee subscription – if you prefer decaf, this is definitely the coffee beans subscription for you! You can also buy one-off decaf coffee in our shop too.

Coffee Bean Types and Their Characteristics

How often do you drink coffee?

Have you ever stopped to think about the many different types of coffee beans or where they come from? The chances are probably not that often!

If you are a self-confessed coffee lover, to really appreciate your coffee we invite you to learn more about the main coffee bean types that are currently found on the market.

The four main coffee types are Arabica, Robusta, Excelsa, and Liberica and all four of them have radically different taste profiles.

Arabica

Known as one of the most popular and well known types of coffee bean, Arabica beans are the most commonly produced variety and are considered higher quality beans. In fact, over 60% of the coffee beans in the world that are produced are Arabica variety.

These beans are grown at high altitudes and need to be in an area that has a steady rainfall and plenty of shade.

Perhaps one of the reasons that this is a variety of coffee bean that is seen the world over is because the trees are easy to care for, they are reasonably small and they are easy to prune too. Although they are delicate and can be affected by their environment. Arabica is both full of flavour and aroma, which is why it’s our offering for our coffee subscription UK plan!

Robusta

The next variety of coffee bean is Robusta, which is the second most produced in the world.

As the name hints, the Robusta bean is both hardy and is also immune to a variety of diseases too.

This type of coffee bean grows best in a hot climate with irregular rainfall and can grow at a number of altitudes too. Compared to Arabica beans, those that grow on the Robusta plant have double the amount of caffeine in them, meaning that they are an excellent choice for a real boost and offer a more harsh flavour.

The beans also have a smooth texture and it is often said that they even have a slight chocolate hint to them, which makes them ideal to have with milk and sugar (perhaps as an iced coffee).

Liberica

One of the hardest types of coffee bean to come by is the Liberica bean. They are larger than the other beans and is the only one in the world that is known to have an irregular shape.

Liberica beans are also unique in their aroma and some say that they are not only smoky, but they are fruity and floral too.

Excelsa

Although having recently been classified as a member of the Liberica family, the Excelsa bean is vastly different in taste when compared to the Liberica coffee bean.

Mostly found in the South East of Asia, it accounts for only around 7% of the worlds coffee.

So there you have it, a full run-through of the main types of coffee. You can check out our range of coffees, coffee gifts, coffee equipment and more in our online shop.

How to make frothy milk

When you are at a coffee shop enjoying a nice drink, one thing that is incredibly satisfying is just how perfectly they manage to froth and foam the milk in the coffee. Whilst you can easily make some kind of coffee yourself at home, it isn’t always easy to know how to make frothy milk.

So to help you to learn more we have put together a helpful guide on how to froth milk at home.

Does every coffee have frothed milk?

Although typically found in beverages such as espresso drinks, cappuccino or macchiatos. It doesn’t really matter what type of coffee it is that you are making, the chances are that you are going to have foamed milk in it. Not only does frothed milk look great but it also helps to improve the taste and texture of the milk within the coffee too.

If you are planning to make a cappuccino then you are going to want to make sure that you have plenty of foam, but if you are making a latte, you won’t be too focused on the froth and more on how it is going to improve the taste and texture of the coffee.

The good news about learning how to make milk froth is it doesn’t matter which type of milk you prefer to have in your coffee, all of these kinds of milk can be frothed and give great results.

What equipment is needed in order to froth milk?

If you want to know how to froth milk at home then you are going to need some key pieces of coffee equipment in order to get things right.

This includes :

  1. Coffee machine with steam arm/wand
  2. Milk jug
  3. Milk
  4. Thermometer

Once you have these items you can start to practice frothing milk and take your coffee to the next step.

How to make milk froth

When it comes to foaming and making frothy milk at home you always need to use fresh milk that is cold and straight out of the fridge. You will need to pour the milk into either a straight-sided or a belly jug. You should aim to fill up the jug between a third and a half of the way, you need to have plenty of milk in there to work with, but you also need to give the milk room to expand too.

Turn on the steam arm for five seconds, as this will remove any of the standing water that may be left in the arm and will also get the pressure starting to build up.

The next step is to place the tip of the steam arm just below the surface of the milk and then turn the steam arm on to full power. If you hear a chirping sound in the milk then you are at just the right power.

As the milk in the jug begins to froth up, you will want to lower the jug, which will make sure that the tip of the wand is submerged in the liquid, rather than being in the froth. Then, heat the milk to the right temperature, add it to your glass and then take the time to clean the seam arm as best you can.

So, now you know more about how to make milk froth yourself, why not get practicing with one of our coffee delivery subscription plans and see what you can create. You might be surprised by the results!

How to Grind Coffee Beans

Whilst some people might be more than happy to drink instant coffee or pre-ground coffee, if you are serious about your coffee then you will want to look into buying a coffee grinder.

Grinding coffee is a simple process, but just like any skill, it can take a few times to achieve the perfect result.

This article attempts to guide you so you can learn more about how to grind coffee beans yourself.

Why is freshly ground coffee better?

If you are looking to achieve a great-tasting cup of coffee it is always considered better to purchase the actual coffee beans rather than purchasing ground coffee from the shops (you can buy coffee beans in our online shop and get your hands on one of the best coffee subscription UK plans).

This is because pre-ground coffee from a packet runs the risk of degrading faster thus becoming stale quicker over time, whereas coffee beans tend to last longer due to still having its protective shell reducing the oxidizing effect.

By manually grinding the beans yourself before making a brew ensures a fresh cup every time.

Grinding the beans yourself also offers more control over the coarseness which can massively impact the flavour of your coffee.

Choosing your coffee grind consistency

One common question when it comes to grinding coffee is just how fine to grind the coffee beans. There are a variety of different grinds that you can aim for. Coarse is when you leave the largest granules of coffee left at the end of the grind. You will often aim for coarse if you are using a cafétiere or a percolator to make your coffee.

A medium grind will feel just like granulated sugar and you will want to opt for this if you have a drip coffee machine, such as the Hario V60 coffee dripper. That said, you can also use this grind for other brewing methods, but it is not suitable if you want to make an espresso.

You can also choose to have a fine grind on your coffee beans. This is the ideal grind for espressos and has a real powdery consistency. This coffee grind is not just ideal for espresso makers but is great for flip drips and filter brews too.

To summarise:

Coarse Ground Coffee

A grind commonly used for French press coffee and is also the best grind for percolators. It is often the same consistency as heavy grained Kosher salt.

Medium Ground Coffee

Great as drip coffee. It is also considered the standard grind consistency for what is found in supermarkets.

Fine Ground Coffee

This type of grind is similar to that of powdered sugar and is needed for making a shot of espresso or for Moka pot coffee (see the Bialetti Moka Pot in our shop).

Choosing your grinder: the different types

Before grinding your coffee, you will also need to decide which type of grinder to use. There are many different types of coffee grinders that are available, here are a few we listed down below:

Blade Grinders

Often associated with the high-speed whirring noise. They are often the cheapest grinders that you can buy and are readily available in many high street stores.

The thing to remember about these particular types of grinders is that whilst they will work, they do not always offer the most precise method and you can find that they hack up and slice the beans rather than creating a fine grind that is ideal for your coffee.

Burr Grinders

The second option is a burr grinder. These types of grinders can be more expensive to buy, however, they are more consistent. Burr grinders use two spinning disk that will essentially smash the coffee beans into a precise and uniformed grind. Burr grinders also offer you the flexibility to adjust the grind from coarse to fine so that it best suits your preferred method of brewing coffee.

They are ideal for grinding your own coffee at home, however, one thing that you will want to keep in mind is that these grinders can become very hot during use and if you leave your beans in there too long then you can find that you burn the beans and ruin their flavour.

Hand/Manual Coffee Grinders

If you are opting for more of a traditional approach on how to grind coffee, then another option you may want to consider is a manual coffee grinder. These grinders come in all shapes and sizes and although they can be hard work, manual grinders offer a cost-effective way on grinding coffee beans yourself.

One element you will want to consider with manual coffee grinders is that when buying one, do ensure it comes with a good quality grip.

How to grind coffee beans

Once you have chosen your coffee equipment and the grind size, try to plan around grinding your coffee just before you decide to brew it. This ensures that your coffee will be fresh and taste better.

Once you are ready to start brewing, the grind can begin! Simply load up your coffee grinder with about two tablespoons of coffee beans per cup (this also depends on how strong you want your coffee!).

Place the beans in your grinder and follow your manufacturer’s instructions.

Note: If you are using a blade grinder, then don’t forget to lift the coffee grinder to give it a little shake between pulses, this will free up the beans while they are still in the machine.

Whether you want to use an electric grinder (which believe us is considerably easier) or perhaps go for something that is a little more manual, either way we can promise you that grinding your own coffee is both satisfying and absolutely worthwhile!

Now you know more about how to grind coffee beans, it’s up to you to decide how fine you will want your ground coffee to be.

What is coffee cupping and how does it feature in speciality coffee?

Specialty coffee is classified as any coffee that has a SCA score of 80 or more and is free of any primary defects within a 350g sample.  SCA stands for the Specialty Coffee Association and they have developed a method for grading and scoring coffee. Those who are qualified graders and who can legally post their scores are called Q graders. This grading involves an inspection of the green and roasted coffee and an assessment of the roasted coffee known as coffee cupping.

It’s important to perform this cupping test as a way of evaluating the aromas and flavours of the coffee, even more so to determine if the coffee is defective or not.

The method of coffee cupping is universal and everyone can do it. No special coffee equipment is needed: just a set of cups, some hot filtered water and a great batch of coffee. The standardised protocol is easy to follow:

  • Place 5 cups of each coffee, ground to a coarse level, and proceed to smell the coffee to determine fragrance. 5 cups are used to identify any defects or lack of uniformity between each cup.
  • Pour hot filtered water into the different cups, ensuring an equal amount of water in each cup.
  • After four minutes, a crust is created on top of the cups, which must be broken. This “break” is an important time to assess the aroma after which point the remaining crust will be cleaned off the surface
  • Next it’s time to slurp – for real. In order to determine flavour, aftertaste, acidity, body, balance and any coffee defects, it’s important to actually slurp each sip. This will help spray the coffee across your palate, which will enable the aromas to reach your nasal receptors. Slurping helps to determine even the most subtle aromas and flavour.
  • Each of these individual steps needs to be scored, which then adds up to a final coffee score. As mentioned before: a speciality coffee needs to score at least 80 out of 100. Also, by scoring different roasts of the same coffee, a roaster can choose the best roast to then reproduce and sell.

The Handpicked coffee subscription UK team has two Q-graders, who also roast and pack the coffee in London Fields. The Q-grade certification means they have passed 20 tests over a period of three days, which include sensory, olfactory, cupping and triangulation skills and identification of organic acids. It demands a lot of cupping practise in order to be able to identify coffee defects.

The programme is run by the coffee quality institute and the purpose is to enable coffee professionals around the world to have the same method of evaluating coffee. A Q grader in Brazil should be calibrated in how they score with a Q grader in Sumatra. In this way a universal language to evaluate and discuss coffee has been implemented.

The Water In Your Coffee

An often overlooked element in the coffee-making process is the one which makes up to 98% of any black coffee – water.

After going to the effort of choosing the perfect coffee subscription service and investing in your preferred coffee equipment, we usually think very little about the water we use for brewing. However this step can prove crucial in bringing out the best in your coffee.

Water quality can vary dramatically depending on your location, so filtering your water is certainly something to consider. Removing impurities from tap water can improve the brightness and character of your brew. Another advantage to using filtered water is that it reduces the buildup of limescale in your equipment, reducing the likelihood of equipment issues in future.

Things to consider:

1. Use fresh water each time. Don’t reboil water and make sure you don’t have it stored in your espresso machine or kettle when not in use. If you reboil the water, it loses oxygen. which is a key element for brewing a fresh, flavoursome coffee. 

2. Use filtered water to ensure you remove any impurities from the water.

Introducing the New SCAA Flavour Wheel

In our Handpicked booklet last month we introduce you to the new SCAA wheel. This is one of the most iconic resources in the coffee industry and is used every day by experts. 

The Speciality Coffee Association of America (SCAA) is the most prominent body in the coffee industry, setting the standards for everything from green coffee to roasting and cupping. The SCAA Annual Expo is the coffee event of the year. Our roaster Hugo attended its 28th edition last month in Atlanta, where one of the highlights was the launch of the new SCAA Coffee Flavour Wheel

The first SCAA wheel was created 21 years ago to offer a common language for coffee professionals to describe the complex taste profiles. Everyone in the coffee supply chain, from farmers to baristas, uses these terms as a shared point of reference, and posters of the wheel decorate the walls of cupping and roasting rooms around the world. Those who have been with our coffee club for a while may remember the wheel from our Spotlight on cupping coffee in March last year.

Now we are pleased to share with you the revised version of the wheel, its first update in 21 years, developed by the SCAA and World Coffee Research to reflect the latest spectrum of coffee flavours and the vocabulary used to describe them.

Use this wheel to describe the various characteristics of your UK coffee subscription. First, take a minute to breathe in the aroma. Next, take a sip, spreading the coffee over your palate and see what flavours you can identify and how they balance each other.

For example, April’s Kenya sits in the fruity category, with a citrus acidity balanced by soft floral notes, while June’s Indian coffee belongs in the top left section i.e. Sweet, Nutty/Cocoa.

To find out how to cup coffee using the flavour wheel, visit the SCAA website at scaa.org/chronicle/2016/02/05/how-to-use-the-coffee-tasters-flavor-wheel-in-8-steps/.

* The Coffee Taster’s Flavour Wheel by SCAA and WRC (© 2016) is licensed under a Creative Commons Attribution – NonCommercial-NoDerivatives 4.0 International License. You may not use this material for commercial purposes.

The Art of Processing

Many factors contribute to the flavour of our coffee, but the way it has been processed at origin has a tremendous impact. This “processing” involves the removal of the fruity exterior of the coffee cherry, something which can be done in a few different ways. So what are the different methods and flavours they produce?

Dry or Natural processing

This is the oldest form of processing. Coffee beans are typically spread out over large surfaces, such as patios or raised beds, and dried. The coffee is laid out for up to 4 weeks to dry while being constantly turned to avoid unwanted fermentation. When the moisture level of the coffee is below 12%, it is then milled to remove the remaining cherry and parchment layers, leaving only the green bean.

While natural processing requires little equipment or water, it can be a very risky endeavour. If the coffee is left out too long or if the coffee is exposed to rain, an entire crop can be ruined. However, if well executed, the results can be spectacular – though this is by no means the status quo.

Natural processed coffees typically have a unique flavour profile with bigger body and higher sweetness, but with less acidity and clarity.

Wet or Washed processing

The first step of the wet or washed processing method is the removal of the skin and flesh of the cherry, which is done by pulping machines. After the initial de-pulping the coffee is then left in fermentation tanks (covered by water) for 14-36 hours, during which time natural enzymes break down the sticky layer of fruit that’s tightly surrounding the beans. This procedure is delicate and timing is critical! If the coffee is left too long, fermented flavours of rotten fruit and acetic acid can be imparted. Because wet mill stations can be very expensive, they often service a whole community of smallholders.

Washed coffees typically have a higher, more refined acidity and better defined flavours, but with less sweetness and body.

Honey or Pulped natural processing

The final method of processing sits somewhere between washed and natural. In this method an amount of the pulpy layer around the bean is removed from the coffee before it is laid out to dry. The result is an intensely sweet and fruity cup. Honey processing is becoming increasingly popular, as it can produce the favourable characteristics of both the natural and washed processes to the degree desired by the farmer. The removal of the skin before drying means the drying happens more easily and there is far less risk of excessive fermentation.

Honey processed coffee can have flavour characteristics anywhere from natural to washed coffees.

The Next Step of Processing Coffee: Drying

An important step in the processing of coffee is the drying of the green beans. Once a coffee has had the fruity exterior removed and only the beans with the protective parchment layer remain, the moisture content of the coffee needs to be lowered to make them micro-biologically stable for shipping. Typically, the moisture content of a mature coffee cherry is somewhere between 50-70% but for coffee to be stable for shipping it must be between 9-12%. In this post we explore the different drying methods and what affect they might have on the final cup quality.

Patio drying

The most common method for drying coffees is patio drying. Green coffee is spread out over a large patio surface at a depth of around 2-3cm and dried under the sun. Drying times for washed coffees are around 6-7 days while a natural may need to be dried over 12-14 days. The coffee must be raked and turned frequently as it dries in the sun to ensure even drying and prevent any bacterial damage.

Raised African beds

In areas with rainfall occurring throughout the drying period, farmers will often use raised African beds. These are raised wooden frames with fine nylon mesh on which the coffee is placed for drying. The coffee is then raked and dried in much the same way as patio drying. The advantage of raised beds is that they allow air to circulate under the coffee and for water to drain away more easily. Raised beds generally result in more even drying and a better quality finished product.

Mechanical drying

The final drying method is mechanical drying. The coffee is put in to machines fuelled by gas or wood, which effectively work like tumble dryers, slowly drying out the coffee with temperatures not exceeding 42C whilst keeping the coffee in motion. Mechanical drying is often used in conjunction with traditional drying methods. For example; a farmer may place coffee on patios for two or three days to initiate drying and finish the coffee off in a mechanical dryer to allow for freshly picked coffee to go on the patios. While this method allows for farmers to get a return for their crop more quickly it may have the undesirable result of not drying the coffee out evenly and resulting high water activity levels.

The method chosen for drying the coffee is important as it can affect the quality and shelf life of a coffee. If a coffee is dried too quickly or unevenly the water activity levels within the coffee may be high. Water activity is the measure of how bound the water is within the coffee seed. If the water activity is too high it can result in green coffee fading and producing past crop flavours more quickly. As an example, we sometimes will find a coffee which tastes exceptional as a pre-shipment sample but has lost its sparkle by the time the full shipment arrives.

Altitude and the Coffee Tasting Profile

The world’s greatest coffees are grown at high altitudes. But why is this?

A general rule of thumb is that the higher the elevation, the denser the bean and the more intense the flavours. The ideal coffee growing conditions are close to the Equator with abundant sunshine and at altitudes where the high elevation produces cooler temperatures during the night. This provides a slower growth cycle for the coffee tree which allows for a more complex development of the sugars in the bean, creating deeper, more interesting flavours. Better drainage at high elevations also reduces the amount of water in the fruit resulting in further concentration of flavours.

What’s more, as altitudes increase fewer insects are present to damage the coffee cherry. Arabica coffee trees are delicate plants vulnerable to pests. Interestingly, Robusta has twice the amount of caffeine as Arabica. Caffeine is a natural pesticide, making Robusta coffee much better suited for the harsher conditions at lower altitudes where insects thrive. Countries such as Hawaii, which grow their coffee at low altitudes around 2000ft- 3000ft produce less complex beans which tend to be fragile and can lose their personality quickly, especially if they’re not roasted properly.

The top coffee producers such as Colombia, Sulawesi, Papua New Guinea and most of East Africa typically grow their coffee’s above 5000 ft. This yields fruitier coffees with floral notes and a hint of spice, which explains all the complex flavours you can taste in your monthly coffee subscription.