[Curiosity] Does the filter paper need to be soaked before brewing?

Do you really want to soak the filter paper before brewing after all?

Curious Saya has been plagued by differing opinions on this issue for quite some time. Though some have performed experiments and written articles, she has never done them herself and finally could not restrain herself.

So on a sunny and slightly muggy morning it seemed destined for taking care of things.

Saya got together with Dabai to conduct an experiment pitting traditional methods against uncommon ones.

-Background-

We have heard positive and negative reasons for soaking the filter paper:

These reasons have been heard from the mouths of baristas who use different brewing techniques. We don’t know if these baristas have ever done these experiments, but they absolutely inspired us to do this experiment.

-Experiment-

• Experiment filter cups: hario V60 ceramic filter cup, kalita stainless steel cake cup, bonavita ceramic smart cup

• Experimental filter paper: Mola, V60 bleached filter paper

• Experiment brewer: SCI Brewing Instructor Dabai

• Experiment coffee: Torch Mountain Man Coffee Beans

• Participating Q-Graders: Internet Persona Joel, Roast Master Little Cabbage, and Curious Saya

• Experiment objective: To compare the TDS, extraction rate, taste and texture of coffee brewed from soaked and non-soaked filter papers under the same conditions of filter cup brewing, water temperature and filter paper. 

Within this process, TDS will be measured by a measuring instrument, the extraction rate will be calculated by a formula, and the taste will be recorded by three Q-Graders. The table of their notes is below:

Instructor Dabai kept performing the test over and over, and our three Q-Graders kept on drinking.

They became a bit excited from all the drinking（I hope they didn’t drink too much…）

Now, to come back to the subject, the final results were quite interesting. 

First and foremost, a table of the combined three Q-Grader evaluations: 

We used these three filter cups to make coffee with soaked filter paper and non-soaked filter paper, respectively. When scoring, we looked at seven different details of the coffee, and summarized the following points:

1. Using non-soaked filter paper or soaked filter paper has little effect on the aromatic trend of the coffee, but there is a clear discrepancy in taste;

2. Coffee brewed without soaked filter paper is stiff, dry and tart, and coffee brewed with soaked filter paper is a distinctive and smooth;

3. When looking at the extraction rate, we can see that the extraction rate of soaked filter paper is marginally higher than that of non-soaked filter paper, though the difference is inconsequential.

-Further Discussion: To Soak with Cold or Hot Water -

After we answered the problem of whether to “soak or not soak the filter paper before brewing,” we discovered another problem: if you must first soak the filter paper, is it better to use cold or hot water?

Consequently, the three decided to seize the moment and simply perform this experiment as well.

We directly used V60 to do the test, brewing two cups of coffee. Before making each cup, we soaked the filter paper, once with hot water and the other with cold water. The data is as follows:

Conclusion:

The sense of sweetness of the coffee made with filter paper soaked with cold water is slightly better.  The texture is thick but mixed, and after it cools, the flavor becomes bitter and astringent.

Of course, we believe that every instrument, every filter paper, and whether or not it is soaked are all ways of making coffee more spectacular. Some friends who like Japanese-style brewing will choose to not soak their paper. The results from this experiment are just a reference.

If you have interested friends, please feel free to conduct your own experiments, and we can communicate about our findings together.

As a roasting company, have you ever made your customers feel that you didn’t meet their expectations?

As a roasting company

I don’t know if you’ve ever heard customers offer feedback like

“I’ve heard many people say your company’s roasted beans are great, so I excitedly bought a bag of coffee beans. After brewing, the result was an unsatisfactory cup of coffee. I wondered is there something wrong with my brewing so after making adjustments, it’s still the same. I feel cheated!”

Of course, the problem lies not with the customer’s brewing, and others who praised the beans were not lying however the customer unfortunately bought roasted beans that had not been quality-controlled.

When a coffee shop or individual buys roasted beans from a roastery, their first wish is certainly that the coffee does not taste bad and the flavor meets expectations.

Second, many customers have their own personal coffee preferences. They tend to purchase the same coffee again and again over a period of time. If the quality of the product varies each time, it will introduce uncertainty into their mind.

This is why roasteries require a set of control systems for testing the quality of their roasted beans. 

On the contrary roasters and quality controllers working in roasteries will discover that many factors limit quality-controlling roast beans. It is not a simple process.

Most roasteries are limited to only testing a cup of roast beans in which after roasting, the roasters will conduct a cup test to evaluate the quality of the beans.

Due to the mainstreaming of the “fresh roast” concept and same-day-delivery requirements, the cupping test must be undertaken immediately after the beans are done.

In this method of quality control many shortcomings are present

• It is impossible to guarantee the quality of coffee by solely relying on personal senses;

• The labor of a roaster is intense thus fatigue can affect sensory perception;

• The flavor is often unstable on the same-day cup test of roast beans;

• And the cup test is not the way customers consume their coffee, allowing for the existence of differences in perception.

We visited some famous roasteries at home and abroad to understand how they control for the quality of roast beans and what difficulties they encounter in the quality-control process.

The American “Light of Arkansas”—Onxy Coffee Lab

This is a boutique coffee company that is the gathering of champions. Independent cafes in the area travel as far as 60 miles to buy roast beans from them.

1. Roasted products are pre-adjusted to a roasting profile and roasters operate according to this profile. Of course the weather and other factors need to be taken into consideration;

2. Testing the color value and carrying out a next-day cup test on roast products. When the profile and color value are regular there are generally no major issues;

3. At the same time the stability of the raw bean quality will be regularly checked.

4. If the beans for a product are used up we will carry out a replacement testing to find new beans and profiles in order to ensure the stability of the flavor.

A well-known boutique coffee chain in China—Seesaw

Seesaw is a successful boutique coffee brand in China. It has approximately 30 stores in China. White-collar workers and coffee enthusiasts compose its main customer base.

1. Raw bean samples are tested in three rounds;

2. Monthly inspection of raw beans in warehouse;

3. The roast team sets the roasting profile and value of coffee power value for testing as well as the cup test.

Difficulty: Because of demand for fresh beans, same-day cup testing must be conducted. Therefor we must leave sample beans for the college to conduct a cup-test and in accordance with reviewing customer complaints, some of the products will need to be returned.

A famous Hong Kong boutique coffee company—Urban Coffee Roaster

A first-rate boutique coffee brand managed by a raw bean merchant. At Urban Coffee Roaster one can taste coffee beans from all parts of the globe.

Main quality control processes:

1. Next-day cup test, mainly using index assessment to evaluate whether or not the flavor of the beans has reached its full expression;

2. After five days, roasted beans will be calibrated with different cooking parameters.

Example: Italian blending imitates the way customers brew. We can record the extraction rate and flavor, then analyze whether or not it is necessary to adjust the brewing parameters or roast profile.

Difficulties: We cannot satisfy the various preferences of different customers.

This requires a system of feedback in the company; maintaining good communication with customers to understand their preferred tastes and brewing habits.

Ultimately improving the roasting profiles to cater to the public in order to facilitate them brewing their favorite coffee.

(P.S. Thanks to Summer, Ale and Lune for their three replies.)

Each roastery has its own unique systems and standards in accordance with  their situation but they all share the same goal: to ensure the quality and stability of their coffee beans.

In the next article, we want to have a conversation with everyone about how to create a quality-control system for roast beans.

As the consumer, have you ever had similar vexing experiences when purchasing roast coffee beans?

At the same time, we welcome other colleagues to share methods and suggestions for quality control in the comment section below.

Ideally through exchange and discussion we can inspire further reflection and provide reference for other roasting friends who place a premium on the quality of their beans to safeguard the beans of consumers.