I have previously written about green coffee in the context of its alleged weight-loss properties and my opinion on the matter. As you know, I have been and still am a staunch opponent of attributing any health benefits to raw coffee beans that roasted coffee does not possess. Therefore, we have not offered you raw coffee in Single Origin until now.

In recent times, home roasting has become increasingly popular - the art of roasting coffee in the comfort of your own home. But you can't roast coffee if you don't have... green coffee beans.

With this article, I want to announce the retail sale of green coffee in Single Origin and provide you with some insights into the subject that I have been passionate about since 2009. I will also share some tips that will undoubtedly help you avoid many mistakes and disappointments, saving you a lot of nerves and money.

Why shouldn't you roast coffee at home?

I'll start with a somewhat unconventional question to outline all the negative aspects of home roasting from the very beginning. There aren't many, but they can influence your decisions:

1. An ocean of aromas - home roasting releases a plethora of odors throughout your home, which can linger for several days. I personally love this aroma, but as they say, tastes differ. The less professional the roasting process (e.g., using a pan), the more aroma is released.

2. Coffee Chaff - when roasting coffee, the silverskin, a thin membrane, detaches from the beans and tends to float around; it is highly flammable. Professional coffee roasters have special containers for it, but at home, it's likely to float around your kitchen, and you'll need to figure out how to deal with it.

3. Unbearable Odor If You Overroast - the roasting process requires constant monitoring and active participation (stirring). If something distracts you and you overroast the beans, it's challenging to get rid of the horrible smell of burnt coffee in your home. It's truly unpleasant and has nothing to do with the wonderful aromas released during proper roasting.

4. Results May Not Meet Expectations - this is the most common issue I encounter when talking to people who practice home roasting. Don't let this discourage you, but be aware that it's challenging to achieve the same results as professional coffee roasters or the tools we use every day in the roastery.

5. Temperature Risks - coffee roasting is inherently associated with high temperatures (around 200°C) and materials that cool relatively slowly (the beans). This always carries the risk of burns or even fires, so it must be done consciously.

6. Technical Requirements - while a pan doesn't require much, home coffee roasting devices may sometimes need exhaust ventilation and/or 380V three-phase power supply instead of the standard 230V electrical outlets.

So, let's roast! But where can you get green coffee?

Subjectively (but also objectively) - from the Single Origin Roastery, where, as mentioned earlier, we have started selling green coffee, raw, unroasted beans from around the world.

Objectively, buying green coffee online is possible, but most of the time, it is labeled only with generic information like "Arabica from Brazil," without specific details, parameters, or harvest dates. Often, raw beans can have distorted moisture content due to washing or other preparation processes that define them as "for consumption."

They may also be old or improperly stored warehouse leftovers that no roastery wants to buy, and various amateur sellers attempt to market them differently.

On the other hand, reputable European importers and distributors of green beans, from whom we purchase fresh harvests, usually require pallet-sized quantities or at least sacks of 60-70kg.

At Single Origin, you can buy as little as 500g of selected raw beans, ensuring that you receive our quality (because we offer you the exact same beans that we roast for you every day).

What green coffee beans should you choose for Home Roasting?

The answer is simple for beginners - the cheapest ones. Your initial attempts are unlikely to yield excellent results, and there is a high probability that you will use this coffee more as a mosquito repellent than for your espresso. The cheapest option in terms of green beans is Indian robusta (or Brazilian Santos if you want to start with arabica right away - which I suggest, as it has a significantly milder and more pleasant aroma during roasting than robusta).

Once you determine that your roasting skills allow you to produce coffee that you enjoy drinking, you can choose beans more consciously for specific purposes.

The choice of beans based on their aromatic and flavor profile is up to you. You can read about the characteristics of individual beans in the descriptions on SingleOrigin.pl. Below, as a reminder, are some aspects (in a very generalized form with many exceptions) that influence the "natural" properties of beans, independent of their roasting:

1. Terroir - the soil, climate, and surroundings, i.e., the region of origin! African coffees usually have a slightly drier profile, with more citrus acidity, and are often used for lighter roasts. American coffees are more likely to resemble the classic coffee flavor and are easier to roast (more on this below).

2. Processing method - dry-processed (natural) coffees tend to have lower acidity, heavier body, and more fruit notes in the aftertaste, which can be a bit "dirty." Wet-processed (washed) coffees generally have more acidity, but their profile is typically nobler and richer than dry-processed ones.

3. Altitude of cultivation - the higher, the better, starting from 1200 meters above sea level. We begin discussing SHG (Strictly High Grown) when we talk about coffees at these elevations.

In addition to the above, I would add one more criterion, keeping in mind the topic of this article - ease of roasting. How do I understand this?

There are beans that require a lot of attention and are very sensitive to even the slightest temperature anomalies and roasting errors. These beans may have an uneven structure and/or moisture content, resulting in uneven roasting (here, Ethiopian Yirgacheffe and various African naturals are at the forefront).

On the other hand, there are beans on the opposite end of the scale - those that roast easily and pleasantly, do not generate problems, roast evenly, and can forgive mistakes, shortcomings, or equipment deficiencies. These are the beans I recommend for home roasting, as they will provide you with a greater sense of satisfaction when experimenting with beans that are more cooperative. In my opinion, in home conditions, Colombian Supremo, Dominican Ocoa, and Nicaragua Finca el Limoncillo from the Single Origin offer the best results.

Of course, I encourage you to verify this proposition through sensory evaluation and try different beans. However, it's worth keeping in mind not to get discouraged by a series of unsuccessful roasts - there are beans that are challenging to roast correctly even in a professional roastery.

Equipment for Home Roasting - What to Use for Roasting Coffee?

In Vietnam or Africa, coffee is still roasted on plates over an open fire, which makes sense in those settings. However, you probably prefer other methods, so I will briefly describe the potential advantages and disadvantages of each method of home roasting.

I strongly advise against using an oven for roasting coffee for two main reasons:

1. During coffee roasting, you need to regularly and constantly stir the coffee, which will be very challenging in an oven without destabilizing the temperature (which will adversely affect the coffee).

2. During coffee roasting, coffee chaff (the thin, dry skin) detaches from the beans, and it will be challenging to remove it from the oven (it must be removed because it can even catch fire).

A frying pan can be a great option for beginners or for fun experiments with friends, although dealing with the chaff it produces can be problematic - it will definitely float around your kitchen. In this version, your home will undoubtedly smell the most like roasted coffee.

Use thick and heavy pans with high sides for roasting. You need to heat it to about 200°C and position the heat source so that the temperature remains relatively stable throughout the roasting process (a thermometer is highly recommended). Then, spread a thin layer of beans (to avoid creating layers) so that each bean has contact with the bottom of the pan. Stir regularly! After a few minutes, you will start to smell the roasted beans, and after another 2-3 minutes, the beans will start releasing chaff.

Around 15-18 minutes after the start of roasting, you will hear a distinctive cracking sound - the first crack, an internal explosion of the bean caused by the increasing pressure inside generated by the water vapor. During the first crack, the beans significantly increase in volume (sometimes doubling), and magical processes begin that largely define the future flavor in your cup (caramelization of carbohydrates, the formation of aldehydes, simple sugars, melanoids, etc.).

Now is the time for the main part of the experiment because these few moments from the first crack to the end of roasting will determine the flavor of your coffee. There is no set time here - simply observe the color of the beans and decide when you think the color is most suitable, bearing in mind that the beans will continue to roast for several seconds after you remove them from the pan due to accumulated heat, so they will darken slightly.

It's essential to cool the beans to room temperature as quickly as possible after roasting. A stainless steel kitchen colander works well for this purpose, but you must continuously move the beans with it for a few minutes - remember that these beans are around 200°C. That's really hot and can cause burns or even ignite if left uncooled in a pile.

A thicker metal sheet (at least 0.5mm) over an open flame may be a better alternative to a pan, and it certainly has more entertainment potential. It's better because it eliminates the two main problems of strictly home roasting:

1. The odors disperse into the fresh air, not throughout your home.
2. You can easily blow away the chaff that is produced, and it doesn't cause any other cleaning or fire hazards.

The issue with an open flame is the fluctuating temperature, but at the scale we're discussing, you can address it with more frequent and intensive stirring - it's achievable, and the memories of roasting coffee over an open flame will be priceless. It's a good idea to prepare a metal tool to collect the beans from the sheet and a container in which you can cool the beans.

You can certainly use any sheet over an open flame, and your imagination is your only limit.

A popcorn machine may seem like a good idea at first glance, and I've seen videos showing successful coffee roasting at home with such machines. However, I see problems. Firstly, popcorn kernels are much smaller, lighter, and more round than coffee beans, so the thermal efficiency of such machines may not be sufficient. Additionally, they may not handle the mixing of coffee as well as popcorn.

Secondly, the roasting time for popcorn is shorter, and prolonged exposure to high temperatures beyond what the manufacturer intended can, in the best case, damage the machine (and in the worst case, lead to an electrical short or user burns).

Finally, if you have a slightly larger budget for home roasting, you can purchase a dedicated coffee roaster. These devices can be divided into three groups:

1. The cheapest, anonymous devices from China in the range of 300-1000 PLN. I strongly discourage them in every aspect; it's not worth the money, and you risk your health and home electrical installation.

2. Budget roasters from more recognized manufacturers (Hario, IKAWA, Kaffelogic, Behmor, Gene) - they cost around 1500 - 5000 PLN and typically offer basic functionalities such as temperature control, autonomous and continuous stirring of roasted beans, and the removal and collection of chaff, allowing you to roast several hundred grams of coffee at once.

3. Professional micro-scale coffee roasting devices, usually intended for conducting trial roasts and building roasting profiles by professional roasters. Prices for basic electric devices start at a few thousand PLN (e.g., Aillio Bullet), and there's no upper limit. Virtually all recognized coffee roaster manufacturers offer sampler versions (with a capacity below 1kg of beans) for roasting samples, but they usually require technical installations for exhaust ventilation, gas supply, or 3-phase power supply. They also take up more space than the devices described in point 2. However, they provide greater control over the roasting process and its parameters, with the option to connect to a computer and control the roasting process using dedicated roasting software.

Is it worth roasting coffee at home - by yourself?

In my opinion - yes and no.

If you have high standards for your coffee and a discerning palate, it's unlikely that you will be able to roast coffee at home as we do in a professional roastery, especially for lighter roasts or more demanding beans.

On the other hand, home roasting can bring you a lot of joy and be a spectacular addition to family or friends' gatherings. It can also significantly reduce the cost of the coffee you consume if the taste is acceptable.

My advice is to give it a try and form your own opinion. Even if you don't succeed, you will be richer and wiser for the experience! And there's nothing stopping you from regularly purchasing coffee roasted by professionals while treating home roasting as a weekend hobby.

Please remember to prioritize safety - 200°C is no joke, and a moment of distraction can lead to harm and significant damage. Roast responsibly!

Most people who drink coffee tend to limit themselves to determining whether it is good or not. In the case of people dealing with coffee professionally, such terms can not say much. Coffee beans are the second most traded commodity on world exchanges (crude oil is the first). The entire industry, from growers over brokers and roasters, to coffee shops and sometimes home coffee drinkers, had to develop some common methods of testing coffee and assessing its quality.

In this article, you can read how to recognize a good quality coffee, what to pay attention to, what deserves recognition, and what is a defect. You will learn what does acidity, bitterness, taste, body or balance really means in coffee. Getting to know these properties of coffee is not difficult at all and even if you do not have the knowledge and skills of professional tasters (and probably not), you will be able to be more aware consumer of the "little black coffee".

As previously mentioned, coffee is a very salable commodity. It flows from plantations in South and Central America, Africa or Southeast Asia to almost every place of earth. Buyers, both large brokerage companies as well as smaller and larger roasteries, must know what beans they are buying and the mere assurances that "you will be satisfied" will certainly not be enough. The coffee industry relies heavily on coffee evaluation forms in this case. Often these are worksheets developed by the Specialty Coffee Association of America or the Cup of Excellence. The big coffee companies (e.g. Tchibo or Lavazza) sometimes rely on their own forms, but these are similar to the earlier ones and the coffee research process is very similar as well.

To the point! The process of evaluating coffee begins well before it is brewed. At the beginning, the grains prepared by growers are assessed in terms of the quality of the green, raw beans - size, number of defects, uniformity or color.

Then, after roasting, the shade of roasting the beans is assessed. Whether they are roasted lightly or strongly will have an impact on other parameters, e.g. acidity or bitterness. Another important issue assessed on a dry sample is the aroma. It is one of the most important things in coffee. It is worth mentioning that raw, green coffee beans have several aromatic and flavor compounds. Coffee has over 800 of them! The essential oils contained in coffee are similar to those of cocoa, hence the smell of coffee sometimes resembles the smell of chocolate. However, experts in their assessments are more accurate. The International Coffee Organization (ICO) lists 18 aromatic shades of roasted coffee:

Some of them are desirable, while others (e.g. rubber) indicate low-quality coffee or serious errors in the roasting process. As an aside, it can be added that roasted coffee is the most aromatic food product.

After analyzing the aroma of dry coffee, it's time to pour hot water over it. All samples are prepared in the same way: 150 ml of water at 92 ° C per 8.25 g of coffee. Brewing takes exactly 4 minutes. After this time, a special spoon "breaks the shell", that is, with a decisive movement, scoops the grounds floating on the surface of the brew. This will allow you to feel the aroma of the brewed coffee (which may be different from the aroma of "dry" coffee).

Next coffee parameters are assessed on the basis of the sample prepared in this way. These are:

Acidity – this is a feature that is controversial among non-specialists. It is commonly believed that this is something undesirable, you can often hear opinions that someone does not like "sour coffee". It must be said, however, that there is a difference between "sour coffee" and coffee having a certain acidity. Without acidity, the coffee would taste bland. The best coffees from Africa, for example the Ethiopian Yirgacheffe, have acidic citrus notes that are noticeable even by laymen, and this is their highly desirable and well-liked feature. The mentioned "sour coffee" is different. This is an undesirable defect that can sometimes result from a wrong production process and resemble vinegar or ferment. In terms of acidity, coffee is somewhat similar to wine: good drinks can have slight citrus notes, while wines that are sour are just bad.

Bitterness - The typical bitter taste of coffee is due to the caffeine it contains. Coffee that is dark roasted has a more noticeable bitterness, which is related to the breakdown of carbohydrates. Roasting too long or roasting at too high temperature makes the coffee too bitter, which is an undesirable effect.

Texture (also named as body or mouthfeel) - The sensations coffee leaves on your tongue. It can be full, which is thick and heavy, or dense (which is a desirable trait) or tart and shallow, which is not very good. The consistency of the coffee is the subjective feeling of stickiness and fullness it leaves on the tongue. If after drinking coffee it feels like a delicate cream on your tongue, it has a "full body". If you feel like a glass of water after drinking it, it is shallow and not very expressive.

Flavor and aftertaste - that is, in fact, the culmination of the aforementioned features. Good coffee has little (to very little) acidity, little to medium bitterness, and a full-bodied texture. The taste is in part the resultant of these features. Coffee has to have some acidity (which doesn't mean it has to be acidic!), There has to be some bitterness in it which comes from the roasting process, and finally it has to be felt on the palate, it cannot flow like water. Good coffee thus oscillates between sweet, bitter and acidic, but not sweet, bitter or sour by itself. For professionals, the so-called "Clean cup", i.e. whether the coffee is free of impurities, "noise", and whether it is free from any sensory errors typical for coffee from a given region (e.g. typical Ethiopia Yirgacheffe should be slightly acidic, with hints of citrus, very little bitterness and medium sweetness, medium to full consistency).

Balance - all the parameters mentioned above and the proportions between them. Coffee may have an intense, desirable aroma and appropriate (usually not too high) acidity, but its other constituent parts may interfere with the perception of the whole (eg bitterness is too high, or the coffee is "flat", ie has not very good "body"). Balance is the point of contact for all the parameters of a good coffee, which is slightly acidic but not sour, has a certain bitterness but not bitter, has a pleasant feeling on the tongue and tastes (and leaves an aftertaste on the palate) just like the coffee in the given the region and the species should be left behind.

I hope that the above article will help you better understand what good coffee should be. Of course, tastes vary, and everyone may like something different.

Getting to know the characteristics of different coffees will certainly facilitate an informed choice. Do you like coffee with a noticeable acidity? Try Arabica from Africa or other continents, but delicately roasted. Would you like to feel nutty and chocolate notes in your coffee?

You will like coffees from America, preferably strongly or at least medium roasted. Or maybe you are interested in "full body" coffees with forest-earthy aromas? Arabica from Indonesia will be perfect for you. The world of coffee, like wine, is quite complex, with lots of varieties and regions of origin, but discovering it is a lot of fun, which I sincerely wish you!