Siphon brewing

A siphon — also written syphon, and sold in English as a vacuum coffee maker or vac pot — is a coffee brewer made of two glass chambers stacked one above the other, with a heat source underneath. It is the apparatus that looks like something from a chemistry bench, and it is the one that draws a crowd in a café because the coffee visibly climbs into the top bulb, sits there, and then gets sucked back down.

Despite the name, no siphoning in the plumbing sense is going on. The machine runs on pressure.

How it works

The bottom chamber holds the water and is sealed by the upper chamber, which has a tube running down into it and a filter at its base. Heat the bottom and two things push at once: the water’s own vapour pressure, and the expansion of the trapped air above it. Together they exceed normal atmospheric pressure, and the only way out is up the tube — so the hot water rises into the upper chamber, where the ground coffee is waiting.¹

The coffee then steeps in the top, fully immersed, with the heat still on. This is the part that makes siphon coffee different from pour-over: it is full immersion at a stable, near-boiling temperature, not a stream of water passing through a bed.

Take the heat away and the bottom chamber cools. The vapour condenses, the pressure inside drops below atmospheric, and the partial vacuum pulls the brewed coffee back down through the filter, leaving the spent grounds in the upper vessel.¹ What you pour is a fully immersed brew that has been filtered on the way out.

The filter is a design choice with real consequences. Cloth and metal filters pass the coffee oils; paper holds them back. That is the same trade-off described on Pour-over brewing and it is why two siphons can taste noticeably different with identical coffee.

Where it came from

Siphon brewing is European and old — considerably older than the Japanese culture now most associated with it.

• Johann Nörrenberg is credited with inventing the vacuum coffee maker in 1827.¹
• The Napier Vacuum Machine, by James Robert Napier, was presented in 1840 and is an early working example of the process.¹
• A side-by-side variant, the balance siphon or Belgian brewer, arranges the two chambers on a balance with a counterweight, so that the emptying of the heated chamber tips the mechanism and snuffs the flame automatically.¹
• The Sintrax coffee maker of 1925, designed by Gerhard Marcks, brought the form into the Bauhaus design canon.¹

Then it largely died in the West, displaced by drip machines and espresso. It did not die in Asia: vacuum brewers remain popular in parts of Asia, particularly Japan and Taiwan.¹ Japan is still building on it — the Tiger Corporation released an automated siphon-principle machine, the Siphonysta, in 2022.¹

Why Japan kept it

The answer is the kissaten. From the start of kissaten culture in the 1920s, some Japanese coffee houses built their identity around the siphon rather than the flannel nel drip the others favoured.² It fitted the room: a kissaten is a table-service house where a single master makes one cup at a time in front of you, and the siphon is the most watchable brewing method there is. Theatre and craft are not in tension there — they are the same thing.

It never became a museum piece there either: contemporary kissaten still run vacuum siphons next to their hand-drip gear, and generally still do not operate espresso bars at all.³ That is also why siphon survives in Japan alongside dark roasting rather than being swept aside by lighter third-wave roasts. It suits the kissaten cup: full immersion, high stable temperature, and a filter that lets body through. The full picture of that culture — the dark roasts, the master, the Shōwa rooms, the 150,000-shop peak — is on Kissaten, and the market around it on Japan coffee market.

To verify — who invented it, and who makes them now

The Nörrenberg 1827 attribution comes from a single encyclopedia entry and was not cross-checked against a patent record or a museum catalogue.¹ Vacuum-brewer origin stories in circulation also credit a Berlin maker named Loeff and several 1830s–40s French patents; those competing claims are not documented here and none should be repeated as fact yet.

Separately, Kono (珈琲サイフオン株式会社) — the other name any siphon user encounters — now has a note, but only a stub one: its site is reachable and confirms the company name and product range, and nothing else about its founding, history or model dates has been established. Hario now has a note, sourced to two of the company’s own pages, but the specific claim that it launched its coffee syphon in 1964 rests on a single secondary article that could not be fetched, and appears in no Hario corporate record read here. Model histories and the halogen-beam heaters commonly sold with siphons in Japan are still undocumented gaps, not omissions.

To verify — no competition or standards footing

No Specialty Coffee Association, SCAJ or World Coffee Events document was consulted that defines siphon brewing, sets parameters for it, or records a siphon competition. Nothing on this page should be described as a standard, a protocol or a championship-sanctioned method. The recipe variables (ratio, grind, steep time) that a siphon shares with every other brewer are covered on their own notes; the siphon-specific numbers are not established here.

Related

• Kissaten — the Japanese coffee house that kept siphon brewing alive
• Nel drip — the flannel-filter method the other half of kissaten culture chose instead
• Pour-over brewing · AeroPress — the percolation and immersion brewers it sits between
• Brew ratio · Extraction yield · Total dissolved solids — the variables any brewer is steering
• Japan coffee market · Third wave coffee
• Hario — the Tokyo heatproof-glass maker whose first coffee brewer was a syphon
• Kono — the other Japanese siphon maker, trading as Coffee Syphon Co., Ltd.

Official links

Siphon brewing is a generic method with no owning body, so the nearest authorities stand in:

• Official site — Specialty Coffee Association of Japan (SCAJ)
• Official site — Specialty Coffee Association

Footnotes

1. Wikipedia — Vacuum coffee maker — confirmed via fetch: the vapour-pressure mechanism and the cooling draw-down, Nörrenberg 1827, Napier 1840, the balance siphon, the 1925 Sintrax, popularity in Japan and Taiwan, and the 2022 Tiger Siphonysta ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

2. Japan House Los Angeles — Brewing Culture: The Story of Japan’s Kissaten Cafés — confirmed via fetch: siphon and nel drip both present from the 1920s start of kissaten culture ↩

3. provenance.kitchen — Japanese Kissaten Coffee Shop Culture — brewing blog; source for contemporary kissaten using vacuum siphons alongside hand-drip and generally not running espresso bars ↩