Scientific brewing

How a German physicist introduced an incredibly pure way of making coffee.

By NEMO Science Museum

Coffee maker Cona (1950/1970) by ConaNEMO Science Museum

In the mid-nineteenth century, the Siphon or Vacuum coffee maker was considered hip and innovative. Nowadays, this type of coffee machine is mainly used in Japan and Taiwan.

Discription of a coffee maker (1823) by Professor NörrenbergNEMO Science Museum

The German professor of Physics, Johann Gottlieb Christian Nörrenberg (1787-1862) was the first to write about this brewing technique in the “Physik und Mathematik” journal in 1823.

He wanted to explain vapour to his students and demonstrate the principle of Aeolipile, in which steam escapes.

The physics machine, as he called it, was easy to assemble. His students followed his instructions and greatly enjoyed the coffee they made.

New coffee maker (1835) by Louis-François-Florimond BoulangerNEMO Science Museum

Due to this professor’s discrete and humble attitude, others are often named as the device’s inventor. This is Louis François Florimond Boulanger, who applied for the first patent in 1835.

Coffee maker Cona (1950/1970) by ConaNEMO Science Museum

The glass sphere and glasses attached above are interconnected via a tube.

The glass sphere holds the water that is heated by a spirits burner, for example.

Once the water is boiling, the vapour creates excess pressure in the glass sphere below. This causes the water to rise up through the tube to the glasses at the top, which contain ground coffee.

By then removing the burner, the temperature in the sphere drops. This causes a negative pressure, and delicious coffee flows back from the jug into the sphere.

Coffee maker (1900/1915) by D.R.P.NEMO Science Museum

In 1878, Herman Eicke upgrades the vacuum coffee maker with balancing technology, which automatically switches off the heat source.

The water is in the right jug. The weight of the water causes the jug to drop to right above the burner.

When the boiling water flows to the other jug, the right jug moves up. This causes the burner to close. The right jug cools off and the coffee begins to flow back. Everything happens automatically!

Watch the brewing process in this video clip.

Coffee maker Cona (1950/1970) by ConaNEMO Science Museum

Some connoisseurs would call this the purest cup of coffee.

This is because the water has the perfect temperature of between 92 and 96°C when it comes into contact with the ground coffee. The coffee is then completely immersed. With help from the low-pressure extraction a subtle, full-bodied, pure and rich coffee flavour then emerges.

Credits: Story

Object of the Month – November 2020

Every month, NEMO Science Museum showcases one of the 19,000 extraordinary objects in its collection. These objects, which were once part of people’s everyday lives, show us how technology has changed over time.

This story was written with the help of Maxim and Deena from Koffie Leute Utrecht, the Netherlands.

- Beschreibung einer Kaffehmaschine vom Professor Nörrenberg, Zeitschrift für Physik und Mathematik, Volume 3, p. 296-272 (1827)

- Nouvelle cafetière à vapeur, BOULANGER Louis-François-Florimond, file number 1BA4893 (1835)

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
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