# Silex Vacuum Coffee Maker

Source: https://dailyextraction.com/methods/silex-vacuum/
Last updated: 2026-10-20

> The Silex is a glass vacuum coffee maker, introduced in the United States in 1915. Water heated in the lower bowl is pushed up into the upper bowl, where it mixes with the coffee; when it's taken off the heat, the cooling lower bowl sucks the brewed coffee back down through a filter. It was popular until instant coffee and the percolator took over.

## At a glance

- Grind: Medium (sand)
- Water temperature: Near boiling
- Category: Vacuum & Siphon (Vacuum)
- Difficulty: Intermediate
- Origin: United States, 1915
- Also known as: Silex, American vacuum coffee pot, Proctor Silex vacuum brewer, glass coffee maker

## Steps

1. **Fill the lower bowl**: Fill the lower bowl with the amount of water you want to brew.
2. **Add coffee to the upper bowl**: Fit the filter in the upper bowl, add the ground coffee and seat the upper bowl in the lower one.
3. **Heat**: Heat the pot on the stove or its electric heater. As the water heats, pressure pushes it up into the upper bowl.
4. **Stir and brew**: Stir the coffee into the water in the upper bowl and let it brew.
5. **Take it off the heat**: Remove it from the heat. As the lower bowl cools, the brewed coffee is drawn back down through the filter. Lift off the top and serve.

The **Silex** brought the [vacuum coffee maker](https://dailyextraction.com/methods/siphon/) into American kitchens. Launched in **1915**, it's a two-bowl glass brewer: water boils in the **lower bowl**, rises into the **upper bowl** to brew with the coffee, then is **sucked back down** through a filter when the pot comes off the heat. It became the familiar **hourglass** coffee maker of the 1930s, had a **7-foot working model** at the **1939 World's Fair**, and spawned rivals like Sunbeam's automatic **Coffeemaster**. Here's how it works and what happened to it.

## The short version

- **A glass vacuum (siphon) coffee maker**, sold in the US from **1915**.
- **Lower bowl heats, water rises, coffee falls** back through a filter.
- **Hourglass shape** by the 1930s, for the stove or an electric heater.
- **Rivals** included Sunbeam's Coffeemaster and Farberware's Coffee Robot.
- **Replaced** by instant coffee and the percolator, then drip machines.



## How does a Silex work?

Proctor Silex describes the principle: water is heated in the **lower half** of the brewer "until the pressure caused the water to rise to an upper chamber. There it mixed with coffee grounds until it cooled and the pressure changed enough to suck the brewed coffee down to the bottom."

1. **Fill the lower bowl** with water.
2. **Fit the filter and coffee** in the upper bowl, and seat it in the lower one.
3. **Heat it** on the stove or an electric heater. Pressure pushes the water up.
4. **Stir** the coffee into the water in the top bowl.
5. **Take it off the heat.** As the lower bowl cools, the coffee is drawn back down through the filter.

Early vacuum pots weren't automatic, Driving for Deco notes: you had to stir the coffee and take the pot off the heat yourself for the coffee to drop. For timings and grind, see our full [siphon guide](https://dailyextraction.com/methods/siphon/).

![Chart of coffee grind sizes from extra fine to extra coarse, with medium highlighted for a Silex vacuum coffee maker](https://dailyextraction.com/diagrams/grind-size.svg#medium "A medium grind suits vacuum brewing and doesn't clog the filter.")

## Where did the Silex come from?

The vacuum coffee maker is European. Proctor Silex says it was invented in **Germany in the 1830s**; Driving for Deco credits an 1830s patent by **Loeff of Berlin**, and the first commercially successful design, the twin-globe pot of **Madame Vassieux** of Lyon, in **1841**.

| When | What happened | Source |
| --- | --- | --- |
| 1915 | The **Silex Company** introduces its vacuum brewer to the American market | Proctor Silex |
| 1915 | Corning develops ovenproof **Pyrex** glass, making a shatterproof vacuum pot possible | Driving for Deco |
| 1930s | The Silex settles into the familiar **hourglass** shape, for stove or electric heater | Driving for Deco |
| 1937 | **Farberware's Coffee Robot**, a vacuum pot that stirs the coffee and keeps it hot | Driving for Deco |
| 1938 | **Sunbeam's Coffeemaster**, a fully automatic, chrome vacuum pot | Driving for Deco |
| 1939 | Silex shows a **7-foot**, fully working glass coffee maker at the **World's Fair** | Proctor Silex |
| 1954 | Sunbeam launches an automatic percolator | Driving for Deco |
| 1967 | Sunbeam ends production of its last vacuum coffeemaker, the C50 | Driving for Deco |

## What happened to it?

Proctor Silex says sales of the vacuum coffee maker were strong "until the convenience of **instant coffee** became popular", and that the vacuum model was eventually replaced by the **[percolator](https://dailyextraction.com/methods/stovetop-percolator/)**, which in turn flourished "until the 1970s when the [automatic drip](https://dailyextraction.com/methods/automatic-drip/) coffee maker was invented". The Silex name lives on in **Proctor Silex**, which today makes drip coffee makers and kettles.

Vacuum brewing hasn't disappeared, though: Driving for Deco notes that siphon pots are making a comeback as coffee lovers rediscover how good the coffee tastes.

*General guidance only. Vintage glass can crack with age, and old electric heaters may not meet today's safety standards, so check them carefully before use.*

## Silex vs other methods

- **[Siphon coffee](https://dailyextraction.com/methods/siphon/):** the full guide to vacuum brewing, with modern recipes.
- **[Cona](https://dailyextraction.com/methods/cona/):** Britain's classic glass vacuum brewer.
- **[Belgian balance siphon](https://dailyextraction.com/methods/belgian-balance-siphon/):** the see-saw vacuum pot.
- **[Stovetop percolator](https://dailyextraction.com/methods/stovetop-percolator/):** the pot that replaced it.

Explore every vacuum method in the [vacuum chapter](https://dailyextraction.com/methods/vacuum/).

## FAQs

### When was the Silex coffee maker introduced?

In 1915. Proctor Silex says the Silex Company introduced the vacuum brewer to the American market that year. Driving for Deco links it to Corning's development of ovenproof Pyrex glass the same year.

### How does a Silex work?

Heating the lower bowl raises the pressure and pushes the water up into the upper bowl with the coffee. When the heat is removed and the lower bowl cools, the pressure drops and the coffee is sucked back down through the filter.

### Was the vacuum coffee maker invented in America?

No. Proctor Silex says it was invented in Germany in the 1830s; Driving for Deco credits an 1830s patent by Loeff of Berlin and Madame Vassieux's 1841 design in Lyon. Our siphon page covers that history.

### What happened to the Silex?

According to Proctor Silex, sales were strong until instant coffee became popular, and the vacuum brewer was then replaced by the percolator, which lasted until automatic drip machines arrived in the 1970s.

### What were its rivals?

Other American vacuum pots, including Sunbeam's automatic Coffeemaster of 1938 and Farberware's Coffee Robot of 1937, according to Driving for Deco.

## Sources

- [Building a legacy in coffee](https://www.proctorsilex.com/building-a-legacy-in-coffee)
- [Silex coffee pot](https://drivingfordeco.com/tag/silex-coffee-pot/)