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Does altitude affect roasting ?

When you decide to start coffee roasting, you are destined to walk on a difficult path. You need to have a strong body, keen senses, swift response, and much chemistry and geological knowledge. All of these qualities serve one purpose, to roast delectable coffee.


When coffee roasting you need to pay attention to several aspects. One of which is the profile of the green beans. The density of coffee is determined by the altitude of the coffee beans. Today we are going to talk about "hard beans" and "soft beans.” Each play a valuable role in the roasting results.

“Hard Bean” and “Soft Bean” are simply our abbreviations for two different densities of beans. Usually the beans in some producing areas at altitude between 1200 to 1400 meter are called hard beans (HB) however the classification system in each country is somewhat different. High altitudes usually have lower temperatures which can make the maturity cycle of coffee beans longer.

During this slow maturing process, the coffee will get a higher sugar content form a good quality organic acid bringing more flavor. Of course, altitude is not the only standard. We also need to pay attention to the latitude of the producing area, which is the distance from the equator. In addition to distinguishing density by altitude, we can also quickly and easily test the density of beans by using some simple tools. Measuring with a graduated cylinder, you can prepare a 1L graduated cylinder.

Then you pour the coffee beans into the graduated cylinder and weigh it. 700 g/L is a dividing line and if it is above this value we can call them hard beans. If it is below this volume we can call them soft beans.

Finally, we can also quickly identify by the middle line of beans. The middle line of hard beans is more tight, on the other hand, soft beans’ is more wide open. There are also varieties that are not affected by altitude. For example, maragogype is commonly known as the elephant beans. This variety of beans is very large in size and is relatively soft according to its low density.

Through the above content, we should have learned how to distinguish between hard and soft beans. Let’s take a look at how to roast. The hard beans are more compact and can withstand higher heat transfer letting us give a relatively high temperature to the beans at the beginning stage of roasting.

Then finish roasting at a medium to high temperature to give the beans enough heat so they can be fully developed. It ensures that the flavor of the coffee is adequately developed to avoid the sour or malt taste produced by insufficient roasting.

When the soft beans are roasted, avoid excessive heat supply that will cause scorching.



This will make the coffee form a dry flavor of distillation such as: charred taste, smoky flavor, and etc. Or it will cause tipping, giving the coffee a grain-like flavor. Therefore we can start with a relatively low temperature for the hard beans and use a low to medium fire to roast the soft beans. The length of time of the same roasting will greatly affect the process.



Beans at different altitudes mean that they have different densities. (Different varieties also will have an effect.)

In summary, the growth altitude of coffee beans will affect your roasting. What I want to emphasize is that there is no versatile curve or formula that allows you to roast high-density or low-density beans because there are too many variables in the roasting process.

Our suggestion is recommended under normal circumstances. I hope that the above content can really help everyone.


7 Key Roasting Requirements for any Roaster

Coffee roasting and roast levels are becoming a more common topic among consumers, and roasting coffee is becoming a more common practice for many coffee professionals and nerds. Roasting coffee has many benefits: it can ensure you are drinking fresh coffee and make your coffee drinking experience more personable. If you are intrigued by roasting but don't know how to start, then keep reading the 7 key requirements I have shared below.

No.1 Purchase a suitable roaster   


You need to start by selecting a roaster that fits your goal. For example, if you are a coffee shop owner, you need to take into account your sales. You don't want to underproduce, but you also don't want to produce more than you need. You also need to think through whether you would use electricity or gas. If you are just a coffee nerd that wants to roast for fun, then you only need to buy a roaster with a smaller capacity. After purchasing the machine, familiarize yourself with your new metal friend; learn how to control temperature, air flow, learn where first and second cracks are, how much heat your machine retains, etc.


No.2 Understand your green beans

The next task is to understand your green beans. Have you ever paid attention to the density, size, moisture content or processing method before starting to roast? How does this information affect roasting? 


Bean density reflects the structure of beans; the higher the density, the tighter the structure of the bean is. If a bean has a high density, it will take longer to absorb heat, leading you to start at a higher temperature or to extend roast time. Therefore, when roasting, we try not to blend beans of different densities.

Similarly, different bean sizes and moisture contents have different heat requirements. If we blend beans of different sizes and moisture contents together, it will affect the consistency of roasting.

Also, different processing methods affect the roasting but this is more apparent in the flavor of the coffee.

No.3 Keep a roast log

In order to maintain consistency, it is necessary to record as much information as possible: green bean weight, bean temperature, flame, air flow, ROR, turning point, first crack, second crack, ending time, ending temperature, and final roasted bean weight. All of this information will help you to analyze your roast, allowing you to accurately adjust your roast plan.


No.4 ROR

ROR (the Rate of temperature Rise) is commonly calculated by the rate of temperature that increases per minute. The number reflects the heat supply in roasting and the speed of roasting. A high ROR means more heat is being applied, increasing roast speed. A low ROR means the heat is being slowly applied, leading to a slower roast speed.


No.5 Have a Plan

A roast plan should include the flavor expectations of this coffee, the time required to achieve this goal, the development time, bean temperature, the end temperature, the power and airflow used throughout the roast.

No.6 Cup your coffee

We can make a roast plan and complete the roasting log to match perfectly, but the taste is king. The goal is to have a delicious cup of coffee. Every roaster needs to evaluate their coffee from the quality of the cup. So a good roaster should have the ability to cup coffee, distinguish flavors, and describe their coffee to their customers.


No.7 Maintenance 

Whether you buy a machine that is expensive or cheap, you need to follow the manual to carry out routine maintenance. Routine maintenance will ensure that the machine is working properly, help extend the life span of your metal friend, as well as guarantee safety during production.

What other key steps are there in roasting? Anything you think I should spend more time explaining? Please share any advice or questions with me!