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How to experiment?

With so many coffee courses being offered both on and offline, many people are starting to blindly regurgitate what others say.

The specialty coffee industry was started by people that challenged the traditional standard of what coffee was and how it was served.


Let us never stray from that.


To promote a more sustainable coffee chain, we need all of the links to be strong. This requires the baristas, brewers, roasters to continually experiment, push the boundaries, and master their craft.

So in this article I want to talk about doing experiments, and give you 2 examples of an experiment I recently did.

As many of you may have learned in middle school science class, there is something called the “scientific method.”

It is as follows: observation, question, research, hypothesis, experiment, analysis, conclusion.

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Observation:

Many brewers have different methods of the bloom, yet they all swear their way is the best.

Stir? Pour slowly? Pour fast? Which ratio is best? Or a 1:2 or even a 1:3?



Question:

What would the effect of changing the bloom temperature and ratio be?

How does changing bloom temperature or ratio affect the overall cup?



Hypothesis:

If I use a lower temperature bloom, then the acidity will be lower.

If I use a higher ratio bloom, then the acidity will be brighter.



Experiment:

It is important to know how to isolate variables. If you change too many variables, you will be shooting in the dark. You won’t know the difference between coincidence, correlation or causation. For example, when I look at one variable, I keep ALL of the other variables constant: dose, ratio, temperature, height, spins, time, etc.



With science, the more objective the better. However, in coffee, TDS and extraction numbers don’t necessarily mean the coffee is delicious. So I will be using TDS, extraction percent, and sensory analysis to compare and contrast the cups.



In any experiment, you need to have all of the variables written down. Be clear which variables you are changing, and which variables you are not changing.



Make sure to write EVERYTHING down: the more information you write down, the better. This will help with analysis, repeatability, and accuracy.

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Experiment 1.

In my first experiment I altered the bloom temperature, but kept all other variables the same:

Bloom time, brew temp, dose, ratio, time, grind size.

For this experiment I invited Q grader instructor Marty Pollack, and Sudanese Q Grader Ahmed Tahmer to taste with me and see.

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The coffee for this experiment was Torch’s Myanmar Wa State, washed processed coffee. This coffee is a very balanced cup of coffee. It has comfortable acidity, medium sweetness, smooth body, and a clean finish.

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Experiment 2.


This experiment was to see how bloom ratio affects the overall cup. I altered the bloom ratio, but kept all other variables the same:

Bloom time, temp, dose, brew ratio, time, grind size.

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For this experiment I invited Q grader instructor Marty Pollack to taste with me and see.

The coffee for this experiment was Torch’s Yunnan Zebra Manor Natural processed coffee.

This coffee is a crazy fermented natural. Comfortable acidity, intense sweetness, thick and smooth body, with interesting flavor notes.

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Analysis:

At this stage, you just point out trends. Try to get all of the trends out and on paper. This will help you draw conclusions. It is important to not talk about “why” just yet. Just clearly point out “what happened.”

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After you identify all of the trends, then take a step back and ask “is there a trend among the trends? Is this trend supported by background research? Why would this be the case?”

My analysis:

Changing the bloom for the clever dripper does not have much impact.

For the v60, the bloom had more of an impact. The TDS and extraction changed, the acidity and balance of the cup were different.

Extracting more out in the beginning, i.e., higher bloom temp and bigger ratio, led to more acidic cups of coffee. Anecdotally, cold brew has low acidity. I have talked with several people that brew cold brew, and they use low temperature water at a long time. The higher temperature led to more harsh acidic tones.


Conclusion:

Combining your background research, experiment and analysis, what can be learned?

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My conclusion:

There are not any hard and fast conclusions that can be drawn. If I wanted to be able to make some hard lines that would be true across several coffees and different brew methods, I would have to repeatedly brew the same coffee over and over to get accurate results. Then I would have to brew with several coffees of different origins, densities, varietals, processing methods, roast dates, etc.


However, what I noticed about increasing extraction in the beginning goes with the background research I have done: acids dissolve quicker, but require higher temperature. This is why cold brew made with low temperature is lacking in acidity.


Under-extracted coffee also has a very harsh acidity with an ‘empty’ aftertaste as the sugars have not dissolved fully into the cup yet.

I never want to blindly follow anyone. I want to know why things are the way that they are. Even if someone else has done an experiment and can objectively prove an answer, it is still important to do it yourself. You can know something to be true because someone else said it, or you can know it to be true because you yourself have experienced it.

Experience leads to wisdom.


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Future development:

In my opinion this is an important step that is not always highlighted. Sometimes in your quest for an answer, you stumble upon a lot more things that you are curious about. You don’t want to constantly chase rabbit trails, but you need to identify these other questions, so you can put time aside later to find the answers.

This is an important step in creating a feedback loop: what went well, what would you change, what other questions do you have?


My Future Development:

Does the quality of coffee matter? Both coffees I used are 84+ coffees. If I were to use 78-82 coffees, how would the extraction be changed?

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In my second experiment I used a grinder that I am not use to using and my brews were all under extracted. Using a grinder I am comfortable with would have led to good extraction. Would a different extraction highlight different aspects of the cup that have been changed?

Maybe.

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The world is a beautiful and complex place. We will never know everything, but it is fun to work and uncover some of the mysteries along the way.

The more I learn, the more I realize that I don’t know very much. This practice of being constantly humbled by the complexity of nature is both frustrating and exciting.

Keep on.

Push the boundaries. Master your craft. Honor the work of the farmers.

  

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.

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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.

Scorching

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.

Tipping

Tipping

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.