Siphon Coffee: The Almost Forgotten Brewing Method With Two Chambers

Siphon Coffee: The Almost Forgotten Brewing Method With Two Chambers

Most cafés today have an espresso machine or a Hario V60. In Tokyo or Kyoto, however, the barista often places a glass construction with two chambers on the counter, lights a small flame, and the water rises upward. A few minutes later the finished coffee runs back down, clear and clean. That is siphon coffee. A method almost two hundred years old, quietly making a comeback in the specialty world.

How the siphon works

The siphon, also called vacuum brewer, has two glass chambers. The water sits in the lower chamber, the coffee comes in later up top. A small heat source, traditionally an alcohol burner, heats the lower chamber. Once the water warms, vapour pressure builds up. That pressure pushes the water through a tube into the upper chamber.

Up there, the water meets the ground coffee. It is stirred, it brews. When the heat is removed, the lower chamber cools down. The vapour condenses, a vacuum forms and pulls the brewed coffee back down through a filter. The result is a clear, transparent coffee with pronounced aromatics, almost tea-like in clarity.

A story from the 19th century

The idea behind the siphon is old. Johann Nörrenberg described the principle as early as 1827. A few years later, in the 1830s, a man named Loeff from Berlin filed an early patent. The commercial breakthrough came in 1840 with Madame Vassieux from Lyon and her two-chamber glass apparatus, which soon stood in the salons of better houses.

In the late 19th and early 20th century, the siphon was a showpiece in fine restaurants, often brewed at the table. With the rise of the espresso machine and later the drip coffee maker, it slowly slipped from European memory.

Why Japan loves the siphon

Around 1920, the siphon arrived in Japan. There it found an audience that did not treat the method as a nostalgic toy but as a serious form of brewing. Glassblowers built reliable devices, Hario still produces them today. Baristas in Tokyo, Osaka and Kyoto developed a near-ritual precision. Every step, every tap of the wooden paddle, every moment considered.

In Japan and Taiwan, the siphon never disappeared. Order a specialty coffee there and you often get it brewed exactly that way. The European comeback is a delayed rediscovery.

How siphon coffee tastes

In the siphon, immersion and filtration meet. The water steeps the coffee in a kind of full-immersion extraction. As the brew flows back down it passes through a fine cloth or metal filter. What arrives in the lower chamber is clear, clean in body and shows the fine aromatics of a light roast in detail. Acidity, fruit and floral notes come through especially well.

If you enjoy filter coffee and the clarity of a V60 or Chemex, you will feel at home with siphon. The difference is stability: in the siphon the water temperature is more constant and the extraction more even, because the water is held at around 90 to 95 degrees Celsius up top.

How to brew siphon coffee

Grind and ratio. Medium-coarse, roughly like coarse sand. A ratio of one to fifteen works well, so eighteen grams of coffee on two hundred and seventy millilitres of water. For darker roasts go a touch coarser, for light roasts a touch finer.

Water temperature. Once the water has risen, it should sit between 90 and 95 degrees Celsius. Hotter brings bitterness, cooler leads to under-extraction and a flat cup.

Procedure. Pour the water into the lower chamber, light the heat source, attach the upper chamber. When the water has risen, add the coffee and stir briefly. Steep for about a minute, then remove the heat. Once the coffee has flowed back, you are done. Total time around one and a half to two minutes.

Filter. Cloth filters, metal filters and, less common, paper filters. Cloth gives more body, metal the strongest cup, paper the cleanest filter character. A matter of taste.

Why the effort is worth it

Siphon coffee is not an everyday drink. The brewing takes longer than a V60, the equipment costs a bit more, and cleaning up is not done in thirty seconds. But once you have had a good specialty coffee from the siphon, you understand why the method has survived. It is not only the cup, it is also the moment before: the water rising, the steam, the sound as the brew flows back. A small piece of theatre that earns its place on a Sunday morning.

At Röstpost

On the Röstpost marketplace you find beans from more than two hundred Swiss roasteries. Light roasts from Ethiopia, Kenya, Colombia or Panama work especially well in the siphon. Pick a bean with fruity or floral notes and you will hear what the siphon can do.