At the risk of exaggeration, there are almost as many ways to make coffee as there are different blends of the stuff. From the French Press and the humble filter, to the Espresso Machine and the innovative Aeropress. But for sheer theatrics, nothing beats the weird-as-all-get-out Coffee Syphon.
It’s certainly not the most convenient method to make your cup of joe, best approached on a quiet Sunday afternoon, but it does produce an amazingly clean and balanced brew with little to no leftover grit.
Invented in Germany in the 1830s, the Coffee Syphon, also known as the vacuum pot, is one of the older methods of producing coffee. It was actually quite popular in most households up until the 1960s, when more convenient coffee machines and instant coffee appeared on the market. They normally consist of two parts made from heat-resistant glass – a lower flask and an upper chamber with a long glass tube and a rubber seal. When placed together, a seal is created allowing a vacuum to be formed. A filter made from metal or cloth is placed between the upper and lower chambers.
The principle of the device is pretty straightforward. Heat some water in the flask, the water expands up the glass tube into the upper chamber where the coffee grounds reside, allow the brew to steep for a minute or two and remove the heat. The liquid then contracts as it cools and moves back down to the lower chamber, getting filtered on the way.
The particular syphon that I have is a TCA-5 made by Hario of Japan, where these things still seem to be reasonably popular. There are many different possible heat sources, stove-top models also exist, but this particular syphon comes supplied with an alcohol burner that sits below the flask. It consist of a cotton wick and alcohol container, the wick is immersed in the alcohol a few minutes before use. Clean-burning alcohol such as methylated spirits should be used, which can be obtained from most chemists.
The TCA-5 comes with a cotton filter secured to a metal disk. The disk also has a spring-loaded chain that you attach to the bottom of the glass tube of the upper chamber. It’s important not to let the cotton filter dry out after use, otherwise stale coffee flavours will stick around, so I keep it stored in a small lunch box filled with water.
A small clip holds the spring loaded chain to the glass tube. I always try to center the filter in the upper chamber as much as possible, this ensures that no grinds can bypass the filter.
The best grind size for the syphon seems to be something between filter and espresso. Not too fine but not overly coarse either.
I always boil up some water beforehand, you can use the burner to do this but I’d imagine it would take a very long time. The burner is then lit and the upper chamber is placed onto the flask.
Once the flame looks clean (more blue than orange), it’s placed under the flask and the whole apparatus is sealed by pressing the upper chamber and the flask together.
Soon after, the water will quickly shoot up into the upper chamber, creating bubbles and a nice coffee aroma.
Once most of the water is gone from the flask, a very small amount will be left in the bottom, allow the coffee to steep in the upper chamber for a minute and stir it. Then the heat is removed and the vacuum takes over.
Pouring out the coffee.
There’s very little left in the bottom of the cup once the coffee is drunk, especially if you compare this to what’s left after a cup of french press coffee.