How does a siphon coffee maker work?

The siphon coffee maker, also called a syphon, originated in Germany and works by heating the lower chamber so steam pressure pushes water up into the upper chamber, where it meets the coffee grounds. The setup has three parts: an upper chamber, a lower chamber, and a stand that supports the lower globe, with a rubber seal joining the two chambers.

Heating the lower chamber makes water rise and complete extraction, and the method later became common in Japan. Choosing a heat source and filter material matters, and parameters such as water temperature, grind size, coffee dose, and coffee-to-water ratio shape the final cup, as shown with a Brazil Queen's Estate bean used for testing.

The siphon coffee maker, also called a syphon, originated in Germany. It relies on heating the lower chamber to create pressure that pushes water up into the upper chamber to complete extraction. It is very popular in Japan, and in recent years it has gradually gained attention among domestic coffee enthusiasts. This article will start with the structure and extraction principle of the siphon, introduce the selection of heat sources and filter materials, and use Front Street Brazil Queen's Estate coffee beans as an example to demonstrate in detail the brewing parameters and operating steps such as water temperature, grind size, coffee dose, and coffee-to-water ratio. Finally, it will recommend coffee beans suitable for siphon extraction, helping readers fully master the essentials of making siphon coffee.

The siphon coffee maker is also called a syphon and originated in Germany. It works by heating the gas in the lower chamber to increase pressure, thereby sending water up to the upper chamber to complete coffee extraction. Today, the siphon is a fairly common brewing method in Japan, and more and more people in China are using it as well.

For more specialty coffee knowledge, please follow the WeChat official account: Front Street Coffee (FrontStreet Coffee)

In many people's perception, the siphon looks as distinctive as chemical laboratory equipment, and it often appears in period films and TV dramas, giving it a layer of mystery. As coffee industry professionals, what Front Street cares about most is how exactly to use the siphon and how the coffee brewed with it performs in terms of flavor.

Structure, Extraction, and Principle of the Siphon

Overall, the siphon can be divided into three parts: the upper chamber, the lower chamber, and the stand. The stand is connected to the lower chamber and serves to secure and support it. The lower chamber is roughly spherical, making heating more even. The upper chamber is cylindrical, narrowing at the bottom and extending into a slender tube, with a rubber seal fitted at the narrowed part. When the upper chamber is placed on the lower chamber, the rubber seal provides a tight seal. At this point, heating the lower chamber causes the water to generate steam, creating pressure inside the lower chamber that pushes the water up into the upper chamber. The upper chamber is exactly where the coffee grounds come into contact with the water. When the heat source is removed, the coffee liquid falls back into the lower chamber, and the siphon coffee is now complete.

Heat sources usually fall into three categories: alcohol lamps, gas burners, and halogen lamps. Front Street uses an alcohol lamp. The tools for filtering coffee grounds are mainly cloth filters and round paper filters. Flannel is a relatively traditional siphon filter material, and its advantage is that it retains coffee oils; its drawback is that use and cleaning are relatively troublesome.

Paper filters are a newer filter material, and their strength is that they filter more thoroughly, even intercepting fine substances such as oils. If you are only drinking it yourself and do not brew coffee very often, Front Street recommends using flannel, so you can experience the taste of siphon coffee more fully. The bead connecting the filter not only prevents sudden boiling when the upper chamber is inserted into the lower chamber, but also helps judge the water temperature through the small bubbles around the bead. In addition to the siphon set and heating equipment, making siphon coffee also requires a stirring spoon and a damp cloth.

Siphon extraction relies on pressure difference: first heat the water in the lower chamber to boiling, then insert the upper chamber so the lower chamber is under high pressure. The pressure difference between the upper and lower chambers pushes hot water upward, where it mixes with the coffee grounds in the upper chamber and extracts. After extraction ends, remove the heat source from the lower chamber. The pressure difference between the upper and lower chambers quickly decreases, and the siphon effect causes the brewed coffee to flow back into the lower chamber. If you want to speed up the return flow, wipe the lower chamber with a damp cloth to further reduce the pressure difference, and the coffee liquid will return faster.

How to Use a Siphon Coffee Maker

To make a good cup of siphon coffee, some details in the brewing process still need attention. Here, Front Street uses its own roasted Front Street Brazil Queen's Estate coffee beans to demonstrate the specific operation.

Water temperature: 88℃

Grind size: 90% passing through a No. 20 sieve

Coffee dose: 18 grams

Coffee-to-water ratio: 1:10

1. Pour 180 ml of warm water into the lower chamber, and wipe the outside of the chamber dry with a dry cloth (to prevent the chamber from cracking during heating). Light the alcohol lamp and place it under the lower chamber to heat.

2. Take out the upper chamber, secure the cloth filter, hook the fixing hook onto the wall of the glass tube at the bottom of the upper chamber, and insert it into the lower chamber at an angle.

3. Pay attention to the condition of the lower chamber. Once continuous small bubbles appear, straighten the upper chamber and insert it vertically into the lower chamber so the upper and lower chambers connect tightly.

4. After the water in the lower chamber rises into the upper chamber, pour in the ground coffee, and stir clockwise from the outside inward with a stirring rod for 10 seconds to ensure all the coffee grounds are saturated with water.

5. Then start timing. At 40 seconds, stir the coffee liquid clockwise again with the stirring rod for 5 seconds; immediately afterward, quickly remove the alcohol lamp and extinguish the heat source. The coffee liquid begins to flow back from the upper chamber to the lower chamber; during the return flow, wipe the lower chamber of the siphon with a damp cloth to speed it up. The total extraction time is about 1 minute 10 seconds.

6. Then gently remove the upper chamber, pour the coffee liquid from the lower chamber into a cup, and enjoy. The siphon coffee brewed this way has a rich aroma. Although its clarity is not as good as pour-over coffee, the oils floating on the surface make the mouthfeel fuller and more mellow.

What coffee beans are suitable for a siphon coffee maker?

In the past, people placed more emphasis on rich, mellow flavor and mouthfeel, and most chose medium-dark roasted coffee beans when using a siphon. The resulting siphon coffee had both a rich aroma and a round, balanced mouthfeel. If you also prefer this kind of flavor, popular options on Front Street's bean list such as Front Street Jamaica Blue Mountain Coffee, Front Street Golden Mandheling Coffee, Front Street Brazil Queen's Estate Coffee, and Front Street Papua New Guinea Bird of Paradise Coffee are all very suitable for brewing with a siphon.

Now more and more people are pursuing more refined coffee flavors, and the choices on the market are also increasingly rich. In addition to the above options, more than fifty single-origin coffee beans on Front Street's bean list can all be used to make siphon coffee. If you want to taste the classic flavor extracted with a siphon, recommended choices include Front Street Huilan with its prominent nutty aroma, Front Street Bird of Paradise known as "Little Blue Mountain," and Front Street Strawberry Candy with its rich fruity aroma. Each has its own characteristics and is also suitable for a variety of extraction methods, so you can choose according to your own preferences.

For more specialty coffee knowledge, please follow the WeChat official account: Front Street Coffee (FrontStreet Coffee)

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