Analysis of Siphon Coffee Brewing Pros and Cons | Siphon Coffee Brewing Experience Sharing and Learning

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The siphon pot is not only aesthetically pleasing but also offers a visual experience when operating. Siphon coffee best expresses the coffee's flavor, highlighting the taste differences between various single-origin coffees, resulting in a richer and more full-bodied taste. Due to heat source heating, the coffee creates high, medium, and low-temperature differences during brewing, generating rich flavor variations. However, some friends encounter issues while using siphon pots. Today, FrontStreet Coffee will share extraction insights about this cool coffee equipment.

Siphon Pot Principle

Although called a siphon pot, it doesn't actually use the siphon principle for extraction but rather relies on pressure differences created by thermal expansion and contraction! The siphon pot structure mainly consists of: a stand, a lower pot, and an upper pot. From the diagram below, we can see that the siphon pot's stand connects to the lower pot, serving to fix and support it. The lower pot is mainly used to hold liquid and heat it, roughly spherical in shape to ensure more even heating. The upper pot is cylindrical with an extended slender pipe. The pipe's contraction point has a rubber ring—a crucial core component.

The extraction process is quite simple. Initially, we fill the lower pot with water and heat it, then place the upper pot into the lower pot without securing it tightly. As temperature rises, water expands and accelerates into steam. At this point, we secure the upper pot tightly, creating a vacuum state in the lower pot. The steam then compresses the space in the lower pot, causing the hot water to continuously climb upward through the pipe due to pressure. While the hot water remains in the upper pot, we can begin adding coffee grounds to implement mixed extraction.

After extraction is complete, we can remove the heat source. As temperature decreases, the steam in the lower pot begins to contract, and pressure returns to normal. At this point, the coffee liquid in the upper pot begins to flow back to the lower layer, while the coffee grounds in the liquid are blocked in the upper pot by the filter. When the coffee liquid has completely flowed down, extraction is complete.

Based on the immersion extraction method, the siphon pot's biggest characteristic is its relatively high extraction rate. Typically, siphon-extracted coffee has a rounder, smoother mouthfeel and a very full-bodied texture. This is mainly due to the vacuum created during extraction and the use of filter cloth, both of which help produce coffee with a more substantial texture. These qualities恰好能让中～深烘焙咖啡豆的表现更佳.

Therefore, if using a siphon pot to extract coffee, FrontStreet Coffee recommends FrontStreet Coffee's Paradise Bird, FrontStreet Coffee's Queen Manor, FrontStreet Coffee's Golden Mandheling, FrontStreet Coffee's Blue Mountain No. 1, and FrontStreet Coffee's Huilan coffee beans.

Siphon Pot Misconceptions

Since the most conventional method for siphon pot coffee is to heat the water in the lower pot until it frequently bubbles before starting extraction, most people believe that siphon pot coffee's extraction temperature is 100°C. However, there are actually two misconceptions here. First, siphon pot coffee's extraction temperature is not 100°C.

In traditional methods, although the lower pot is heated until it continuously bubbles, the hot water at this point has not yet reached boiling point, at most around 96°C. The bubble chain simply accelerates bubble formation. Then, when the hot water from the lower pot is transferred to the upper pot due to pressure, the water loses temperature due to the upper pot's material and heat absorption from the surrounding environment. FrontStreet Coffee measured the hot water reaching the upper pot and found the temperature to be only around 92-3°C.

Another misconception comes from the point where pressure difference forms. It's not that water needs to be heated to boiling to produce steam and pressure. Water evaporates at any temperature, though at lower temperatures, the evaporation speed is relatively slow. If we secure the upper pot before frequent bubbling occurs, the hot water will still be pushed to the upper pot, though at a relatively slower speed.

In other words, siphon pot extraction temperature is not singular. We can determine the water temperature to use based on the set extraction time or the roasting degree of the coffee being extracted.

For example, if we want a longer extraction time or are extracting difficult-to-extract light-roast coffee, we can use a higher temperature. If extracting darker roasted coffee beans or wanting a longer extraction, we can let the water temperature be lower! The same logic applies to grind size consideration: longer extraction time, darker roast, coarser grind; shorter extraction time, lighter roast, finer grind. (But note that even at its coarsest, siphon pot grinding is still finer than pour-over grinding)

Siphon Pot Filtration Tools

In addition to the stand, upper pot, and lower pot, the siphon pot contains a small tool—the filtering device connected to the bubble chain! The filtering device can be fitted with different filters according to our preferences: such as filter paper, flannel filter cloth, or other filters (non-woven fabric). (The bubble chain has many uses, like helping us better observe temperature changes, preventing violent boiling, etc. So from the beginning, we need to properly place the upper pot)

In the article "The Difference Between Filter Paper and Filter Paper is Greater Than the Difference Between Humans and Chimpanzees," FrontStreet Coffee mentioned that these material differences not only change water seepage speed but also determine the retention level of oils and particles in the coffee liquid.

Filter paper has the highest precision, so when we use it as a filter, the produced siphon coffee will have relatively high cleanliness, with stronger flavor recognition when drinking. The disadvantage is that it's too clean, lacking the soul of siphon coffee (as friends in the comments section said)! Therefore, generally when we make coffee for ourselves and don't mind the trouble, FrontStreet Coffee recommends using flannel filter cloth as the filtration tool for siphon coffee.

The disadvantage of flannel is that it's expensive and relatively troublesome to clean. But the advantage is that it possesses the soul of siphon coffee—it can retain the coffee's oils and some particles in the liquid, giving the coffee a richer aroma and more full-bodied texture.

Siphon Pot Coffee Grounds Addition Sequence

There are two ways to add coffee grounds in siphon coffee: "pre-addition" and "post-addition." Pre-addition means adding coffee grounds to the upper pot before hot water enters due to pressure difference, then waiting for the water to rise for extraction. Post-addition refers to adding coffee grounds after the hot water has completely risen to the upper pot, then mixing for extraction.

(The following image shows post-addition)

Each method has its advantages, but generally, FrontStreet Coffee more recommends that novice friends use the post-addition method. Because this method has fewer variables and relatively even coffee extraction. With pre-addition, the extraction degree of coffee grounds will differ due to the order of contact with water. While this can bring more layers, it also requires higher understanding from the operator.

Siphon Pot Stirring Methods

When you buy a siphon pot, besides the main siphon pot body mentioned above, it also comes with a stirring rod. This is because siphon coffee extraction belongs to immersion extraction, so during the making process, stirring operations will be used.

There are many stirring methods, such as the tapping method, circular stirring method, cross stirring method, Z-shaped stirring method, and even infinity-shaped stirring method... Besides the tapping method, other stirring methods have relatively strong stirring intensity, which can significantly increase coffee extraction rate (specifically depending on stirring force and speed). The tapping method uses tapping to push coffee grounds into the water, mainly aiming to fully wet the coffee grounds. We can choose which methods to use based on our extraction method, with no limitation to using only one.

Auxiliary Tools for Siphon Pot

In addition to the two tools mentioned above, when extracting siphon coffee, we also need to prepare two additional items: cloth and heat source.

We need two cloths in total: one dry cloth and one wet cloth! The purpose of the dry cloth is to prevent explosions! Before starting to heat the lower pot, we need to wipe off any moisture from the siphon pot's lower pot. Otherwise, due to the presence of moisture, the lower pot can easily cause explosion risks during heating. The purpose of the wet cloth is to control the speed of coffee liquid return, which we'll discuss later, so we won't explain too much here.

There are many choices for heat sources, such as gas stoves, light wave ovens, or alcohol lamps—as long as they can heat. Common gas stoves and light wave ovens can control heat intensity, with relatively fast and stable temperature rise, though the cost is somewhat high. While alcohol lamps have low cost, they have smaller, unstable heat sources and longer heating times. But no worries, they all work! Use whatever you have, though FrontStreet Coffee suggests that when using alcohol lamps, it's best to add hot water rather than room temperature water to the lower pot, otherwise the heating time is really long!

Important Notice :

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