How to Use a Royal Belgian Coffee Maker Step by Step

If you’ve ever watched a barista use a dramatic, two-chambered glass and metal contraption to make coffee, chances are it was a Royal Belgian siphon pot. Also called a Belgian or vacuum brewer, it’s a theatrical yet precise way to brew coffee using vapor pressure and vacuum suction. But how does it actually work—and can you use one at home without ruining your morning?

The Royal Belgian coffee maker brews a full 420–450cc cup of coffee using a two-chamber system: water heats in the lower brass or glass kettle, rises via siphon action into the upper glass brew chamber, and then is pulled back down after cooling. It uses an alcohol burner and a balance lever. All you need is ground coffee, water, and about 5 minutes.

What Is a Royal Belgian Coffee Maker?

The Royal Belgian (or Belgian) siphon coffee maker is a stovetop or standalone brewer made of glass and metal. It consists of two main parts: a lower water kettle and an upper glass brewing chamber. A siphon tube connects them, and a filter sits at the bottom of the upper chamber. When heated, water rises into the upper chamber under pressure; once removed from heat, a vacuum pulls the brewed coffee back down into the kettle. It’s a visually engaging way to make filtered coffee using basic physics.

How Does the Siphon Process Work?

This coffee maker operates on basic scientific principles: heat, pressure, and vacuum. When you heat the water in the lower chamber, steam pressure increases, pushing hot water up the siphon tube into the upper brewing chamber where it mixes with coffee grounds. Once the heat is removed—either by letting it cool or manually extinguishing the flame—the vapor pressure drops, creating a partial vacuum. This causes the brewed coffee to be sucked back down through the filter into the lower chamber, leaving grounds behind.

How to Use a Royal Belgian Siphon Coffee Maker

Here’s a step-by-step guide using the exact method described for optimal brewing:

• Close the water tap (valve) on the lower kettle, then turn open the water tank stopper and pour in 420–450cc of water. Secure the stopper afterward.
• Add your desired amount of coffee grounds to the upper brewing chamber. There’s no set dose, so adjust to taste.
• Press down the balance lever, open the alcohol lamp cover, and light the alcohol burner beneath the lower kettle.
• As the water in the kettle boils, the increasing pressure forces the hot water to travel upward through the siphon tube and into the upper glass chamber. This is driven purely by the siphon effect.
• Once all the water has transferred into the upper chamber, the lower kettle lifts slightly due to the pressure shift. At this point, the alcohol lamp’s cover automatically closes, cutting off the flame. The upper chamber holds the hot water and coffee grounds mixture while brewing occurs.
• After brewing, as the system cools, a vacuum forms in the lower kettle. This gentle suction pulls the brewed coffee back down through the filter and into the lower chamber, leaving the grounds in the upper part. To help this process, slightly loosen the water tank stopper to allow air flow.
• When the coffee has fully returned to the lower kettle, open the valve and pour your freshly brewed coffee.

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Frequently Asked Questions

How much water should I use in a Royal Belgian coffee maker?

Use between 420cc and 450cc of water. This is the standard range cited for a full single serving in the original instructions, filling the lower kettle before heating.

Do I need to measure the coffee exactly?

No exact measurement is given, so use an amount of coffee to your taste preference. The key is to fill the upper brewing chamber with your desired dose before the water rises into it.

What kind of alcohol lamp fuel should I use?

The article doesn’t specify the fuel type, but traditional Royal Belgian brewers typically use denatured alcohol or ethanol-based burners. Ensure you’re using a fuel safe for alcohol lamps.

Why does the coffee go back down after brewing?

After the heat source is removed, the system cools and creates a vacuum in the lower kettle. This vacuum pulls the brewed coffee through the filter and back down into the lower chamber, separating it from the spent grounds.

Can I use any kind of coffee grounds?

Yes, but grind size matters. For siphon brewing, a medium-fine grind similar to table salt is ideal to ensure proper extraction during the few minutes the grounds are in contact with hot water.

Is the automatic shut-off safe?

Yes. When the water finishes rising and the lamp cover closes automatically, it cuts the flame. This is a built-in safety feature of the Royal Belgian design.

Recommended FrontStreet Beans for Siphon Brewing

For siphon coffee, try FrontStreet Coffee’s Ethiopia Humbera for floral and citrus brightness, or their Yirgacheffe for juicy berry and stone fruit layers. Both single origins highlight the clarity and vibrancy that siphon brewing enhances. Their washed processing shines through in the cup, offering clean, nuanced flavours ideal for this method. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.