Siphon Brewing Guide: How to Brew a Clean, Aromatic Cup

The siphon (also known as a vacuum pot) is a visually striking brewing method that uses vapor pressure and vacuum force to produce an exceptionally clean, aromatic cup. Though theatrical in appearance, the siphon is a highly precise brewer capable of remarkable clarity and balance.

When brewed correctly, the siphon highlights brightness, sweetness, and aromatic complexity while maintaining a silky mouthfeel. Because it relies on timing, heat control, and proper sealing, attention to detail is essential.

 

What Makes the Siphon Unique

Unlike gravity-driven or immersion brewers, the siphon uses pressure differentials to move water between chambers. This means:

• Water rises into the upper chamber through vapor pressure
• Coffee brews fully immersed at stable temperature
• Vacuum action draws brewed coffee through a filter

The result is a clean, expressive cup with excellent aromatic lift and clarity.

 

Recommended Grind Size

Grind: Medium-Coarse

A medium-coarse grind allows water to flow cleanly during drawdown while providing sufficient extraction during immersion.

Grinding too fine restricts drawdown and increases bitterness, while grinding too coarse produces a thin or underdeveloped cup.

Uniform grind size is critical for smooth vacuum action.

 

Coffee-to-Water Ratio (8 oz Reference)

This guide uses 8 fl oz (240 ml) as the standard reference size.

• Coffee: 15–18 g
• Water: 240 ml (8 fl oz)
• Ratio: Approximately 1:13 to 1:16

Lower ratios increase intensity and body. Higher ratios emphasize clarity and aromatic nuance.

 

How to Brew

1. Add 240 ml of water to the bottom chamber.
2. Apply heat until the water rises into the upper chamber.
3. Add 15–18 g of freshly ground coffee to the upper chamber.
4. Stir gently to fully saturate the grounds.
5. Brew for 1–1½ minutes while maintaining steady heat.
6. Remove the heat source.
7. Allow the brewed coffee to draw back down into the lower chamber through the filter.
8. Serve immediately.

Avoid aggressive stirring, which can disrupt extraction.

 

Brew Time and Temperature

• Water temperature during brew: 195–205°F (90–96°C)
• Brew time: 1–1½ minutes in the upper chamber

Over-brewing increases bitterness and dulls aromatics.

 

Scaling the Recipe

The siphon recipe scales linearly when maintaining the same ratio.

• 12 oz (360 ml): 22–24 g coffee
• 16 oz (480 ml): 30–32 g coffee

Larger brews require careful heat control to maintain stable pressure.

 

Common Mistakes to Avoid

• Over-brewing beyond recommended time
• Grinding too fine, restricting drawdown
• Poor seals or dirty filters
• Excessive stirring

Small errors significantly affect clarity and aroma.

How to Adjust Flavor

If the coffee tastes weak or flat:

• Increase coffee dose
• Extend brew time slightly

If the coffee tastes bitter or harsh:

• Shorten brew time
• Grind slightly coarser
• Reduce heat

Always adjust one variable at a time.

 

Taste Profile

A well-brewed siphon cup is:

• Exceptionally clean
• Highly aromatic
• Bright and lively
• Silky with tea-like body

It excels at highlighting delicate flavors and complexity.

 

The Bottom Line

The siphon is both precise and expressive. By controlling grind size, heat, and brew time, it produces a clean, aromatic cup with remarkable clarity and balance.

Mastering the siphon is about control, patience, and consistency.

For a cleaner, filter-focused brewing method that emphasizes clarity over theatrics, explore the Chemex brewing method.