American-style pour-over and Japanese-style pour-over differ noticeably in technique, roast level, grind size, and water temperature. Among these, the American-style pour-over's unique stirring motion and relatively high water temperature produce a rich, bitter flavor. This article provides a detailed analysis of the process for making cold brew coffee with a Chemex pot, and delves into the four key extraction points: grind size, time, stirring, and temperature. It also compares the flavor differences among the direct pour method, the standard blooming method, and the blooming-with-stirring method through experiments. The article also specifically recommends related products from Front Street Coffee, offering practical reference for coffee enthusiasts.

For professional barista exchanges, please follow Coffee Workshop (WeChat public account: cafe_style)

American-style method: cold brew coffee with a Chemex pot

[Cold Brew Process]

60g grounds (light roast beans)

205°F, i.e. 96°C water temperature

Medium grind

450g ice cubes

Pour in 100g water, stir

Pour in another 350g water

You will find that with the same coffee beans, the coffee made with an American-style pot compared with pour-over will be noticeably more bitter and more astringent. The key is that the high water temperature of the American-style pot causes this phenomenon. Ordinary American-style pots actually spray and extract through atmospheric pressure.

Simply put, when the power of an American-style pot remains unchanged and external environmental factors change little, the extraction water temperature and water flow rate are relatively stable, and this extraction temperature is too high while the water flow rate is somewhat slow, resulting in over-extraction. Bitterness and astringency come about this way, and this is exactly the bitterness Americans like.

There are differences between American-style and Japanese-style. Although American-style and Japanese-style may both use the same dripper, there are still some differences in coffee bean roasting, grinding, filter paper, water temperature, and technique.

The biggest difference is that American-style pour-over requires stirring the coffee grounds with a stir rod while pouring, somewhat like our stirring technique when making siphon coffee; whereas pour-over coffee in Japan, South Korea, Taiwan, and China only uses water to pour in circles, and never uses a stir rod or bamboo strip to stir the coffee grounds.

Typical American-style flavor is mainly based on medium roast and dark roast: rich + mild bitterness + sweetness. It has both bitterness and sweetness in character. For grinding, medium roast uses a medium grind, water temperature is between 80-85°C, and the pouring speed is medium.

For dark roast, use a fine grind, water temperature between 85-90°C, a thin stream and slow pour, and the bitterness is stronger. Americans often drink a cup in the morning to wake up quickly, and it is also called "dawn coffee."

[American-style brewing is relatively simple]:

First, the grounds must be ground very fine, basically similar to espresso;

Second, the water temperature is around 90°C;

Third, blooming, similar to the Japanese style;

Fourth, while slowly pouring water in circles, after stopping the pour, stir with a wooden spoon or bamboo strip. Stirring also has different techniques: one is stirring back and forth in a cross shape; the other is stirring in circles.

For extraction, there are four important points:

<一>, Grind size, the size of the coffee particle clusters. The fewer the clusters, the higher the extraction yield (small clusters, but in large quantity, have a larger surface area exposed to water ), so when the flavor is not enough, the simplest method is to adjust finer.

Given the above two points, this can explain why poor grinding easily produces off-flavors, because there are many extremely fine particles, which locally raise the extraction yield, manifesting as off-flavors.

<二> ,Time. Under otherwise identical parameters, the longer the time, the higher the extraction yield. Everyone knows this.

<三>,Stirring. Adding external force will increase the extraction yield, whether through an additional vessel or through the water flow.

<四>,Temperature. Beans of different roast levels require different water temperatures.

Blooming-with-stirring method

Blooming stirring method : Use a stir rod to stir, usually during the blooming stage, perform one cross-shaped stir to allow the water to fully contact the coffee grounds and increase the release of aromatic substances. After that, the methods vary: some do a circular stirring motion after the first pour, after the second pour, or after the third pour; some use a single-pour method and then stir; and some stir during all three pours. As long as it is properly controlled, any of these methods can work.

This method can effectively enhance the release of aromatic substances while also having a notable effect in highlighting flavor. The downside is that it is relatively difficult to control the degree of stirring. Too much stirring will produce a harsh acidity, and after a while it will become bitter and astringent. The force must also be gentle.

Advantages : The stirring method can amplify the strengths of the coffee beans, especially enhancing the coffee's mouthfeel, and it will not be too thin.

Disadvantages : Although it makes the flavor more obvious, its sweet aftertaste is weakened a lot . Moreover, this method has very high requirements for coffee bean quality. If poorer coffee beans are used, it will only infinitely amplify their undesirable flavors. Also, because this method requires a very fine coffee grind , combined with sufficient stirring, it is easy to over-extract if not handled properly.

In my view, making coffee is a very small matter. Forgetting form and boldly trying new methods is always extremely interesting. The stirring brewing method is simple, common, and very cool.

1. During the blooming stage, the water amount is blooming-with-stirring > direct pour > standard blooming; in the later stage it is direct pour > blooming-with-stirring > standard blooming; however, if the initial blooming water amount is 50g (corresponding to 20g of grounds), then the entire instantaneous water flow trend chart will be different; the amount of water poured during the blooming stage will determine the instantaneous water flow trend in the later stage of brewing, so the instantaneous water flow trend chart in the article will also change.

2. From my experience with the blooming-with-stirring technique, I would adopt a shorter extraction time than standard pour-over (because since you have stirred, you have accelerated the possibility of even extraction, so of course there is no need for such a long extraction time).

In your experiment, the extraction time for blooming-with-stirring = standard blooming = direct pour. This approach of limiting the extraction time to be the same will of course very likely lead to the article's viewpoint that "coffee made with blooming-with-stirring is more turbid and dull." Because the coffee may have been over-extracted.

How to stir to brew delicious coffee

Recently we have noticed that many people have begun adding the motion of stirring with a wooden stick during the process of making pour-over coffee. This inevitably aroused our curiosity: during pour-over, aren't we already constantly stirring the coffee grounds with the water flow? Is it necessary to stir again with a wooden stick?

When I raised this question, I decided to use experiments to prove it.

According to extraction principles, if the same time, the same water temperature, and the same extracted substance are used, then under the same disturbance conditions, the same solution should be extracted. We do not believe that coffee will have the same result at the microscopic level, but after multiple experiments we can summarize a certain flavor trend. Therefore, we designed the following three techniques for the experiment:

1. Direct pour method: continuous pour with no interruption and no blooming, spiral pouring method

2. Standard blooming method: bloom for 30 seconds (medium roast), then spiral pour

3. Blooming-with-stirring method: bloom for 30 seconds (medium roast) and during blooming stir with a wooden stick for 10 seconds, then continue spiral pouring

During the experiment, the grind size, dose, water-to-coffee ratio, total pouring time, and water temperature used for each coffee bean were all the same. The three brewing processes were:

Direct pour method: Pour 320g of water at a constant rate throughout. For medium roast, the pouring time is 2 min; for dark roast, the pouring time is 1 min 30 s;

Standard blooming method: First pour 20g of hot water. For medium-roast coffee grounds, bloom for 30 s, then pour at a constant rate and finish at 2 min;

Blooming-with-stirring method: First pour 50g of hot water (because too little water would make stirring impossible, 50g of hot water is poured here during the blooming time), stir to make the water and coffee grounds contact evenly. For medium-roast coffee grounds, bloom until 30 s and then pour, finishing the pour at 2 min; for dark roast, bloom until 15 s and then pour, finishing the pour at 1 min 30 s.

When discussing from both the sensory and data aspects, it is temporarily difficult for us to explain why the direct pour method and the blooming-with-stirring method, although their numerical values differ little, have flavor profiles at two extremes. From the results, we can only infer that because the blooming-with-stirring method accelerated the extraction of flavor substances in a shorter time, it dissolved some heterocyclic macromolecular substances, causing a more turbid mouthfeel;

In the direct pour method, the water flow also has an effective stirring effect, and effectively increases the extraction yield of small-molecule acidic substances, thus showing a brighter acidity in sensory terms.

We sincerely hope that more advanced experiments can help explain the essential differences between the two stirring methods.

Some website content references:

Barista official website

The above content is compiled by CoffeeHunters, a coffee news website.