Coffee Brewing

Filter coffee has been gradually becoming one of the major trends in the specialty coffee industry. At some points, it looks like a very Asian thing because it is slow, crafty and needs a dedication to brewing. However, it is totally not like that. The approach to brewing coffee is almost like science. Not only do we taste the brewed coffee to evaluate the cup, but also we seriously measure various data to understand the things behind the numbers and to maintain the quality of the cup we have been producing.

6~7 years ago in Australia, there were not many cafes doing filter coffee or batch brew or a similar type of coffee which contains nothing except the coffee itself and water. However, nowadays, it is more popular and easier to grab a cup of filter coffee, whether it is batch brew, which is a kind of machine brewed coffee, or a pourover, which is a manually extracted filter coffee by a barista. This new trend pushes the boundary of the coffee industry to bring a more unique characteristic flavour of specialty coffee, giving baristas the opportunity to start a conversation with customers through the flavour of coffee, not just talking about ordinary things. As the industry has been moving forward, general consumers are slowly getting to know what the flavour of specialty coffee is, the difference between the origins and what is good and what is bad in coffee quality.

KEY FACTORS OF BREWING

As the quality of coffee gets more important, baristas are always required to understand what the key factors of brewing are. Although there are a number of different variables affecting the cup, I would like to simplify them to three key factors.

Understanding Coffee

For a better brewing of coffee, we need to first understand the coffee itself. It really matters where it is from, what the variety is, how it is cultivated and processed, how it is roasted and even how long it has been since it was roasted. Generally speaking, region, variety and processing method have huge effects on the flavour of the coffee. For instance, microclimate generates its character in the coffee, some of the varieties such as geisha, pacamara and sudan rume have their own strong characteristic flavours and some processing techniques create totally different flavour profile to others. The information we have about coffee allows us to understand how we approach brewing, what sort of flavour we should look for from the coffee and how we appreciate the coffee.

Brewing Technique

There have been a number of different brewing techniques for many people to apply, and ‘Pourover’ has become very popular because it is easy and convenient.

However, without understanding the technique, it is very difficult to brew a cup of coffee keeping the excellent quality. This requires baristas to pay attention to details such as grinding size, how many times we divide the pouring, water temperature, brewing time, brew ratio, et cetera.

Equipment/Water

It is also important to know the equipment you are using. It could be Hario V60, Kalita Wave, Aeropress or Chemex. Each tool has their own design and structure on purpose which produces a different water flow, different contact time and requiring different grinding size which ultimately develops different flavours of coffee. Water has become one of the major factors in brewing because it takes up approximately 98.5% of brewed coffee. Not only the total dissolved solids in water is a meaningful number but also we need to take a look deep into what is in the water. For example, differing quantities of components (Magnesium, Calcium or Bicarbonate etc) can bring different flavours and textures to the coffee. Moreover, the brewing temperature is associated with different organic acid in coffee which makes different flavour characteristics.

HOW DO WE APPROACH?

The first step to making a better cup of coffee I believe is to develop a standard brewing method which you are comfortable with. This is very important not only because the brewing method can control the quality of the brew, but also the firm, strong and stable brew method is fundamental to start the tasting and evaluation of the coffee. It is not always suggested to have your own signature brew method, but it would be great if you are able to develop the standard method, from there you can start a number of brewing options.

Then, the second step is to get to taste and to evaluate the cup. If you are an experienced barista, you may taste and evaluate the cup by yourself. However, it is always recommended to check with others (someone who has more experience than you) and ask what they think about the cup. Then, you can adjust the brew to make it better.

HOW DO WE ADJUST THE VARIABLES?

The most important variable of the coffee brewing is ‘BREW RATIO’. Imagine that you are making a big pot of chicken stock. You would add more chicken or reduce the amount of water if you wanted to make the chicken stock stronger. You are not going to dice the chicken or boil the stock for 10 or more hours which would be inefficient. The simplest way is adjusting the water or the ingredient. The same thing applies to coffee extraction. If you put in more coffee, it becomes stronger. Alternatively, by adding more water, it becomes weaker. It is like finding a sweet spot between the different ratios. Apply different brew ratios to find the best, sweetest and the most delicious point.

Then, you can adjust grinding size to develop the quality and the tone of acidity and the texture of the coffee. Usually, finer grinding size makes a heavier and low acidity tone and a coarser size makes a lighter and brighter tone of acidity.

After that, you may feel like you are still not happy with the brew. Then, you can start considering the water components, water temperature, different techniques, et cetera to develop the flavour of the coffee.

There is no secret in coffee brewing. So many different methods, techniques, approaches, knowledge are broadly available on the internet. Have an open mind, listen to what others are saying and do not be scared to try. The more you try, the more you discover and the better skill and knowledge you will achieve. Happy brewing!

by Chanho Hong