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The must-try summer coffee

 

Summer is around the corner. A cup of hot coffee is less tempting for most people. However, as coffee lovers, we still need our caffeine fix as usual. 

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A friend from Chongqing (Hotpot city) asked me about cold brew coffee because she would like to introduce a new beverage in her recently opened hotpot restaurant.

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My first reaction was: This is cool! It’s a bold and chic combination, and yet its flavor is mysterious. 

My friend has inspired me to understand what cold brew is and how it is made.




What is cold brew?

     

Many people know about cold brew from Starbucks.

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We usually order a pour-over or siphon single-origin coffee as hot brewed, i.e., using hot water to extract coffee and also then drinking it hot.

Cold brew is different from ordinary iced coffee, which was brewed with hot water and then added into ice cubes. 

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Cold brew is to extract coffee using room temperature water or even ice water.

Due to low temperature, substances with larger molecules, such as tannic acid, are not easily extracted. Therefore, cold brew coffee is smooth, less bitterness, and has zero astringency.

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Cold beverages are instantly refreshing durning the hot summer. Cold brew not only energizes our brain but is also convenient. It can keep the original flavors of the hot coffee we love, depending on coffee varieties and roasting level, but now with the new trend of home-made cold brew. 



 Market Trend

   

In fact, cold brew has been popular in the U.S. for quite a while and is still increasingly trendy.

Data show that as new products continue to surprise us, sales of cold brew in the United States in 2017 are 28% higher than those of regular iced coffee, and by 2018 it is 40% higher. Meanwhile, cold brew is more popular in Canada than in the United States. To put it into perspective, in 2018, Canada sold 85% more cold brew than regular coffee!

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The cold brew trend is continuing to get hotter and hotter.


Nitrogen cold brew coffee is amazingly delicious!

By adding nitrogen into the cold brew coffee, a unique silky and dense texture will be created. While drinking, countless small bubbles make the mouth feel thicker and smooth.

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In addition, nitrogen helps keep coffee liquids fresh.

According to Matthew Hartings, a professor of food chemistry at a university in the U.S., coffee is highly oxidizable.  Similar to rusting of iron, the longer it’s exposed to oxygen, the more acid and bitterness it produces. Therefore, adding nitrogen can slow down the degradation rate of coffee flavor substances.

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Through adding nitrogen, the oxygen in the coffee liquid is forced out, which makes the flavor essences in coffee more stable.

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In the hot summer of almost 40 degrees, who can refuse a glass of smooth, delicious and flavorful nitrogen cold brew?



Making and storing is easy

   

Most of cold brew can be produced in bulk. Since it's extracted in a lower temperature, cold brew beverages can be stored for a longer period of time, which is convenient for (chain) coffee shops of higher volume. 

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Creative recipes


    --How many ways to serve cold brew?

    -- The answer is infinite!



You can make different extraction cold brews by adjusting water and coffee ratio, or adding juices, syrup, honey, milk, soda, alcohol or even food.

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Maybe my hotpot restaurant owner friend will dip hotpot food into cold brew coffee and eat. Who knows, it may work! The recipe combinations of cold brew drinks are beyond your imagination.

For example, at Torch café, we added nitrogen into cold brew coffee, which makes an explosive mouthfeel. 

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Not only do we have millions of flavor combinations, but also thousands of creative packaging ideas. 

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Some designs are dazzling and too lovely to resist. 

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Some cold brew capsules are designed as pocket-sized takeaway cups. 

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Some are like tea bags that can be soaked and drunk. 

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Mixed with Gin is also a popular choice. 

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Maybe you would like some spice.

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Of course, you can be adventurous and add fruit and cream. 

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For coffee shop owners, these are all ideas of seasonal drinks! 

How can we not love this one drink that satisfies our many desires? Come on and check out this trendy beverage immediately! 

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We’ll share more about the theory and methods of making cold brew next time. Stay in tune and feel free to share your thoughts or recipes! 

  

How Well Would “Interception” Help In Brewing Coffee?

As a barista, I noticed many of fellow baristas remove the brewer from the carafe before all the water has dripped through. This was a common practice in most pours.

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I wonder, does this “interception” technique make coffee taste better? If so, will it improve the flavor of brewed coffee universally and by how much? 



what is “interception”?


“Interception” is to cut water from fully dripping through carafe, as seen in the clip below.

Interception

Interception

When we pour water into coffee grinds, a number of compounds are dissolved by water.

No interception

No interception

Using “interception,” a portion of the dissolved compounds are removed with remaining water. 




Three stages of coffee extraction


This begs the question: Why do baristas love “interception”? First, we need to know how coffee is extracted.


70% of a coffee bean is non-extractable lignocellulose, and 30% of the substance can be extracted. Of this 30 % of substances, good substances are usually only about 18% - 22%. Therefore, our goal is straight forward: we want to extract as much of the good from coffee as possible, and leave behind the bad.

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Fortunately, not all substances in coffee are extracted by water at the same time, depending on the molecular sizes. The first extraction includes the smaller molecules such as “acidity,” then the medium molecules such as “sweetness," and finally the larger molecules such as “bitterness” or “astringency” that are unpleasant to taste. This provides a good understanding of “interception” technique.

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The purpose of carefully controlling or deliberately cutting off the flow of water after brewing is to prevent the bad bitterness from affecting the cup of coffee.





“Interception” is one of the many modulation methods



Ultimately, the goal of interception is to avoid bitterness and astringency, and to make brewed coffee more delicious.

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But there are many ways to modify extraction, so much so that "interception" has become the "lifeboat" for many baristas to avoid bitterness, perhaps because it is the most convenient (lazy) way.


Meanwhile, the disadvantages of “interception” technique are also obvious.

  • Interception can easily lead to under extraction and a loss of coffee flavor during the middle and later stages.

  • Beginning learners can struggle to grasp the interception point, which leads to an increase in inconsistencies of the brews.

  • It takes about 30 seconds to a minute after the final pour until the drip is finished. During this period, baristas can become distracted by preparing the drink presentation. However, while using interception, we mustn’t leave sight of the brewer until it reaches “interception point,” which could unfortunately slow down bar flow during a cafe’s busiest hours.

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I will be the first to admit, there are some prejudices about the "interception" approach. We will use the most intuitive experiments to unlock this method, but how much will interception help in the brewing process?



3 experiments- extraction recipe comparison


For this experiment, I selected three brewing cases. We tested a set of slightly different extractions methods for each example (standard without an interception, standard with an interception, adjustment variables without an interception) and compared the sensory of different extraction recipes.



Medium/dark roasted single origin 


Since third wave specialty coffee shops tend to serve lighter roasted espresso blends, it’s harder to find medium/dark roasted single origin coffee in specialty coffee shops.

Many baristas have grown accustomed to using light roasted beans. When brewing medium/dark roasts while using the same recipe, it is easy for a cup to become astringent. Is “interception” a way to redeem darker roasted coffees?

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If you have an understanding of the roasting experience, you know most organic acids and enzymatic chemicals that cause floral and fruity aroma will decompose earlier on. However, caramel, spices, and other flavor substances are created when roasting temperature increases. Dark roasted coffee extracts most of its substances in the middle and later stages.



We compared four brewing recipes:


  • Coffee: Yunnan Washed  

  • Roasting level: Medium/Dark  

  • Grind: 3.5 

  • Water Temperature: 90℃

  • Water/Coffee Ratio: 1:15

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As we can see, “interception” in this case was not a good choice. By adjusting the temperature, the extraction was reduced. At the same time, the extraction of bitter macromolecule substances was mostly avoided, resulting in a good cup of washed Yunnan coffee.

High density coffee extraction recipe

Coffee from higher altitude is relatively more dense. In order to express the complexity of high-density coffee, roasters usually use a lighter roast. Because of its high density and light roasting profile, this kind of coffee is difficult to extract and has many fine grinds.

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We compared three brewing recipes


  • Coffee: Ethiopia Yirgarcheffe  

  • Roasting level: light  

  • Grind: 3.5 

  • Water Temperature: 91℃

  • Water/Coffee Ratio: 1:15



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Larger dose extraction recipe

15-20g is the usual dose we use to brew coffee. Many baristas are not sure how to brew a larger dose, because the larger amount of grinds calls for a longer extraction time. This means that some of the coffee grounds steep for a long amount of time, which causes uneven extraction and higher probability for bitterness and astringency.

Would “interception” be a helpful way to avoid this problem?

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We compared four brewing recipes



  • Coffee: Yunnan natural   

  • Roasting level: light   

  • Grind: 3.5   

  • Water Temperature: 90 Dose: 30g   

  • Water/Coffee Ratio: 1:15

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It's difficult to brew perfect coffee in a larger dose, but it is impossible to achieve this goal by changing one single parameter or simply cutting off the water flow.

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After to reducing the water/coffee ratio and water temperature at the same time, a relatively balanced cup of coffee was finally achieved.

Through the sensory analysis of several different groups using common brewing methods, we can see that the interception technique used by many baristas can make for better cups of coffee, but it is not the best solution for every type of bean.

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There are many ways to adjust extraction in order to brew more delicious coffee. No matter how we use it, we should adjust the variables according to the actual situation rather than copy all kinds of championship recipes. Otherwise, in the end, the cup of coffee will only perfect in figures but not in taste. 

What are your views on the various methods of brewing? We would love to exchange ideas.