Coffee Roasting | The Process & Its Purpose

coffee roasting

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Coffee roasting is a hot topic among connoisseurs.

But it should be more than a trend.

Roasting your own coffee should be at the top of your list of coffee buying decisions.

Its processes are both quite difficult and time-consuming, but that’s one reason why the end result tastes better!

In this post, you will learn the process of coffee roasting, its importance, and if you can roast your own coffee at home in case you want to embark on the journey.

What Is Coffee Roasting?

Coffee roasting is the process of converting green coffee beans to roasted coffee beans.

Green coffee beans are introduced to extreme temperatures for short periods of time.

Roasting brings out the natural oils in the bean, which are released when heated.

This oily substance is called chaff, which forms a crust over the beans so they don’t burn.

The crust also protects the exuded oils from dehydration, which keeps them fresh.

During roasting, aroma compounds are produced that give coffee its familiar flavors and scents.

One example of an aroma compound is volatile organic compounds (VOCs), which have distinctive odors.

Coffee Roasting Process

Coffee roasting is the process of heating coffee beans to their optimal temperature so they release their flavor and aroma compounds.

It brings out the best in the beans so you can enjoy an amazing cup of brewed or cold coffee drink!

The roasting process plays an important role in the taste of your coffee.

As your beans begin to roast, they’ll begin to ‘break down’ and absorb oils from other aromas within them.

This can affect the taste, making your coffee taste bitter or dry.

The process is as follows:

Step 1– The coffee beans are first put in an airtight drum.

Step 2– A drum is designed with heaters that heat the beans inside. The drums rotate in order to spread the heat evenly across the surface of the beans.

Step 3– The heat draws the moisture out of the beans, which evaporates and carries away flavor.

Step 4– The beans are heated until they reach an optimal roast; very light roast for cold coffee drinks, medium roast for brewed coffee, and dark for espresso.

When the beans reach their optimum color, they are removed from the heat.

What Is The Purpose Of Roasting Coffee Beans?

The main goal of roast, besides aroma and color is taste.

Before you start roasting coffee beans, you should figure out why you want to roast them in the first place.

Let’s say you are expecting guests at any time of the day or night, and you want to prepare some coffee ahead of time (instead of serving them cold).

You will need to make sure that your beans are roasted long enough so they get all their flavor and aroma compounds released, but not burned.

So, the purpose of coffee roasting is to make sure that you get the right flavor and aroma from your beans as you want them.

Types Of Coffee Roasts

There are many different methods to roast coffee beans.

But all of them follow the same basic procedure of heating the beans until they reach their optimal roast whether for brewed or espresso-based coffee drinks.

This type of coffee is also referred to as “light-roasted”.

Light roasted Arabica beans are used to make espresso-based drinks, while Robusta is used for making stronger tasting coffees.

For other specialty types of coffee, there are different techniques and temperatures that can be used and most will prefer using their ideal method for each type of coffee.

There are a few different types of coffee roasting techniques used for beans, but the most common is the “French Roast“.

This means your beans have been heated until they take on a light brown color.

This process squashes the oils from the beans, changing their flavor slightly.

French Roast coffee is often preferred for espresso-based drinks, but it can be used for other coffee drinks as well if you’re looking for a change from your traditional roast style.

If you prefer a lighter roast to your coffee bean, you can use a technique called “Arabica Light Roast”.

This means your beans will be roasted until they take on a light brown color, but it will not roast the beans until they become dark brown.

This type of roast is used for both espresso-based drinks and other specialty coffee types.

If you’re looking for a medium-dark roast to your coffee bean, then you’ll want to choose the “Arabica Medium Roast”.

This type of roast is often not recommended for espresso or specialty drink recipes but can be used in other coffee preparations.

The “Dark Roast” is the type of roast used for making stronger-tasting coffees, such as Columbian or French Roast.

It may be roasted slightly into the medium to dark brown range, but most of it is very light brown in color.

There are many different types of coffee roasting techniques that can be used to create different types of drinks for your enjoyment.

Whether you prefer espressos or drip-brewed coffee, there are several choices available today with various types of roasts for endless possibilities.

For more information on the different types of roasted coffee beans, check out our article here. Enjoy!

Coffee Roasting At Home

Before you can roast beans, you have to buy them first (green beans).

If you are looking to roast your coffee beans, you have to do it correctly otherwise, they will not be any good for consumption.

Some people make the mistake of thinking they can use their oven or even a grill.

The problem with doing this is that the beans are not contained in a drum, so the heat cannot reach them evenly.

This means you will either burn them, or under-roast them.

There are two popular methods for roasting coffee beans at home.

The first is using a stove-top roast. This involves placing your beans over a heat source, such as the stove or an electric plate.

You will need to make sure you roast them slowly, and stir them around so everything gets an even roast.

This is the preferred way for beginners, as it is easy to do and makes less mess than other methods.

The second method is by using a popcorn popper.

They work by having your beans inside and heating up the chamber, so it works similar to an oven without the actual heat coming from above.

You will have to watch the beans carefully, so you don’t overcook them.

Once your beans have reached their desired roast color, remove them from the popper and place them in a storage bag for later use.

If you are using the oven, make sure it is not hotter than 400°F (200°C).

You can also use the stovetop, but make sure you don’t heat it over 600°F (315°C).

How Much to Roast Coffee Beans?

The most important thing with each method of roasting is that you can’t lose track of how much time you spend.

The most common advice for how long to roast your beans is around 8-12 minutes.

For many people, this may be too short of a time, so they may want to increase it, which is why it’s important that you stick to the same amount each time.

Mistakes To Avoid When Roasting Coffee At Home

Coffee roasting is an art that can be learned over time by different roasters.

But there’s always a right way and a wrong way to do it; here I’ll provide some common mistakes to avoid:

1. Over-Roasting

It’s important to roast the beans just until you’re happy with your roasted flavor.

There’s no point in roasting them for an excessively long time, because the beans will continue to release moisture and lose flavor after they’ve been removed from the heat.

You don’t want to burn the beans or cause any type of “burnt” smell.

So be sure you remove them from the heat at approximately 1 minute before your desired level of roast has been reached.

2. Under-Roasting

Roasted coffee tends towards bitter flavors due to the degradation of some compounds that result in changes in its flavor.

An under-roasted coffee is one that has not been roasted for the right amount of time, meaning the beans have not finished their process of being roasted.

You can check what you have by smelling your beans – they should have a slight, but pleasant coffee scent.

The best way to verify how long you need to roast is by actually measuring out the correct amount of time with a digital timer or stopwatch.

Try this method if your beans are too dark or too light to tell what they are doing easily.

3. Cooling The Roast Too Quickly

Properly done, it’s important to let the heat penetrate the bean evenly but quickly cools them down before removing them from their heat source.

Take them out of the heat source before they get too hot. This will result in a more even roast, and no “burnt” smells.

4. Using Bad Beans

Try to get the best beans you can get for your money – but make sure they’re actually worth your money!

Freshly roasted coffee is delicious, but the second it gets ground up, it goes stale very quickly.

Don’t use old beans unless you want a satchel of old, stale coffee grounds in your pot!

This is why it’s better to buy whole coffee beans and do it yourself rather than buying pre-ground coffee at a store that has been sitting there for months.

You can grind them yourself just before you use them for a fresher taste.

5. Not Drying the Beans

It’s important to be sure that your beans are completely dried after roasting them to get a better taste from them.

If they are moist, it will result in a weak, bitter flavor from your coffee or espresso beans.

Always dry the beans before using them for brewing or grinding because this will prevent any harsh tastes from happening.

Coffee Roasting Machines

In the coffee industry, there are two types of industrial coffee roasting machines: drum and air roasters.

The drum type generally has more features and cook faster but it’s also more expensive than the air roaster.

However, there are very good air roasters for people who want to roast their own beans without spending too much money on an appliance they will use only occasionally.

1. Drum Roasters

Drum Roasting machines are very simple to use; this is their main advantage.

However, the drums are not made of steel like other laboratory equipment, so they tend to be more fragile.

To make sure your drum roaster is always in good condition, you should take care of it regularly.

The frequency you need depends on how many drums you have; every two weeks is enough for one drum.

2. Air Roasters

Air roasters have a similar functionality to a comparable drum roaster but they cook faster.

They don’t have the same drawbacks when it comes to keeping them clean or maintaining them.

Also, they are a lot more versatile.

Roasting your beans at home is a very rewarding experience.

You can decide how much you want to spend on an air roaster and to roast for how many people, making it a pretty inexpensive hobby.

How Long Does Coffee Takes To Roast?

It’s important to remember that the type of bean you use will influence how long it takes to roast.

The more delicate the bean, the longer it will take.

If the coffee beans are still in their fresh form, then they might take extra time when roasted.

You should use freshly bought beans whenever possible so that they can be used in a shorter amount of time.

Since there are different types of roasts, Light Roast, Medium, and Dark Roast, they will take different amounts of time – with the darkest roast taking the longest.

This is because the beans are slowly cooked with hot air or oil which allows them to expand.

Let’s take a look at the amount of time taken for each type of roast below:

Light Roast

For this type of roast, the beans are roasted until they are white to brown.

This is the type of coffee you would normally buy in the supermarket or which you might be used to on an espresso machine.

It usually takes around three to seven minutes.

Medium Roast

For this type of roast, the beans are roasted until they are golden brown.

The darker this roast is, the longer it will take to cook (and of course – more expensive!)

This is the most popular roast of all for home coffee roasting.

It usually takes around eight to 13 minutes.

Darker Roast

This type of roasting takes the longest.

For this roast, the beans are roasted until they are almost as dark as how they come out of the roaster.

This gives you the full flavor and the taste of coffee beans roasted to perfection.

It usually takes around 20 minutes to 30 minutes.

Is It Worth It To Roast Your Own Coffee?

If you’re someone who likes to drink coffee the way it was meant to be, roasting your own beans is a very rewarding experience.

You can decide how much you want to spend on an air roaster and roast for how many people, making it a pretty inexpensive hobby.

However, if you do not have the time to do it yourself, I suggest that you buy whole roasted coffee beans and grind them before using them.

Doing this will ensure that you know how to get the most out of the beans and select them appropriate for your cup.

Roasting your own coffee at home has its advantages.

Roasting your own beans is a very inexpensive alternative, and if you take good care of your roaster, it’s going to last much longer than you have expected.

Also, it’s great for those who can’t tolerate their coffee being too strong as it lets you control the degree of roasting.

Also, this process allows you to know exactly what goes into your cup and not have to worry about chemicals or additives that could be harmful for your health.

Finally, roasting your own coffee is a great hobby that allows you to spend some time with your friends and family.

You can create a relaxed atmosphere and enjoy a good cup of coffee whenever you want it.

How To Roast Coffee Beans In The Oven

The biggest obstacle to home roasting coffee beans is the use of an oven.

Remember that ovens are designed to bake things, not roast them, so you need to make sure you are using it correctly.

The best way to do this is by setting up a fan near the oven door to get the desired effect.

Roast your beans in batches rather than all at once because otherwise the temperature of the beans could drop quickly and unevenly during the second batch if they were all in one place.

If possible, try to use a digital thermometer that will allow you to detect temperature fluctuations minutely.

This will help you ensure that your batches are roasted for exactly the right amount of time.

The first step is to get the right tools and equipment:

  • A large bowl (preferably not metal) with a lid or glass jar. You need to make sure that this is big enough to hold all your beans during roasting.

Also make sure it’s made of glass or ceramic, as they can tolerate more heat than materials such as steel and plastic.

  • A timer with an alarm that goes off at intervals of ten minutes or less.
  • A fan to help aerate the beans through the oven door.

The next step is to roast your coffee beans.

If you’re using an oven with a timer, set it for 10 minutes (or less) for each batch.

If you’re using an oven without one, start by placing your bowl or pan of beans on the middle or upper shelf of the oven and with the fan blowing around them, turn it on at 400 F (220 C).

Remove once your beans have turned a light golden colour.

This is often called the “Wet” or “White” roast, and it can take from three to seven minutes, depending on how dark you want them

With the Darker Roast you can begin to roast at around 8 minutes, so keep an eye on them, as they can easily burn during this time if the temperature gets too high.

One family member recalls making a rather large mess in her oven after this happened, so do be careful!

When they have reached a good level of darker brown, turn off the oven and allow them to cool for around 15 minutes before trying to separate your beans out.

Final Thoughts on Coffee Roasting

As you can see, the coffee roasting process needs to be done with great care to make sure that each bean is roasted perfectly.

Roasting the beans is simply the way that’s been used for centuries to produce a better tasting coffee.

There are several ways you can roast your beans, depending on how you want them to turn out.

Some of the best machines are the drum type that utilizes hot air from an external source to roast coffee.

While you’re roasting your coffee at home, make sure it’s a clean process by following all safety precautions related to your roaster and your environment.

You’ll always want to make sure that the beans don’t get burned during the roasting process because this can ruin their taste and value.

Follow these tips and you’ll get a high-quality roasted coffee bean for a reasonable price.

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