Brew Library / Brew Guides
Syphon
Brew Guide
No other brew method makes coffee the way the syphon does. It is part science experiment, part ritual, and entirely serious about the cup it produces. When you understand how it works, the results are unlike anything else in your brew collection.
The syphon, also known as a vacuum pot or siphon brewer, was developed in Europe in the 1830s and refined into its modern form in Japan where it became a fixture of specialty café culture. It uses vapour pressure and vacuum to move water between two chambers, immersing coffee grounds at a precise temperature before drawing the finished brew back down through a filter by suction. The process is visible, dramatic, and produces a cup that is exceptionally clean, intensely aromatic, and full-bodied without sediment.
The syphon is not an everyday convenience brewer. It requires setup, attention, and cleaning. What it gives in return is a level of aromatic clarity and flavour intensity that no other manual method matches. It is the brewer you use when coffee is the occasion, not just the morning routine.
Understanding the Device
The Science Behind the Syphon
The syphon operates on two physical principles: vapour pressure and vacuum. Understanding both makes the brewing process logical rather than mysterious and helps you diagnose problems when they occur.
When the lower globe is heated, water temperature rises and vapour pressure builds inside the sealed vessel. Once pressure is sufficient, it forces the hot water up through the syphon tube into the upper chamber where the coffee grounds wait. This is the brew phase: grounds and water are in full immersion contact at a stable, elevated temperature. When the heat source is removed, the lower globe cools, pressure drops, and a partial vacuum forms. That vacuum draws the brewed coffee back down through the filter into the lower globe, leaving the spent grounds in the upper chamber. The filter does the separation work entirely through the suction of the vacuum.
01
Lower Globe
Holds the water before brewing and collects the finished coffee after. Made of borosilicate glass. Sits on the heat source.
02
Upper Chamber
Holds the coffee grounds during the brew phase. Connects to the lower globe via a glass or metal tube sealed with a rubber grommet.
03
Filter
Sits at the base of the upper chamber and holds the grounds back as the brew is drawn down. Available in cloth, paper, and metal mesh.
04
Heat Source
Alcohol burner, halogen beam heater, or butane burner. Each produces different heat intensity and control. The heat source significantly affects the brew.
05
Stand or Frame
Holds the two globes aligned and secure. The upper chamber must seat firmly into the lower globe or the vacuum seal will fail.
06
Stirring Paddle
Used to agitate the coffee grounds once water arrives in the upper chamber. Bamboo or silicone. Critical for even extraction.
Filter Options
Choosing Your Filter
The syphon filter is one of the most consequential choices in syphon brewing. Each filter type produces a meaningfully different cup and requires different maintenance. Unlike other brew methods where filter choice is a minor variable, in syphon brewing it is a primary one.
Recommended
Traditional
Cloth Filter
The original syphon filter. Produces the fullest body and most aromatic cup. Allows some oils through while blocking all sediment. Requires rinsing after every use and soaking in clean water between brews. Must be replaced every 2 to 3 months. Gives the most authentic syphon experience.
Clean Cup
Paper Filter
Disposable and convenient. Produces a cleaner, brighter cup closer to pour over in character. Less body than cloth but more aromatic clarity. Always rinse before use to remove paper taste. Good choice for light roasts where clarity is more valuable than body.
Durable
Metal Mesh
Reusable stainless steel mesh. Allows the most oils through, producing the heaviest bodied syphon cup. Some fine sediment may pass through. Easy to clean. Good for medium and dark roasts. Not recommended for light roasts where clarity matters.
For beginners, paper filters are the easiest entry point: no soaking, no maintenance, consistent results. Once you are comfortable with the syphon process, transition to cloth filters for the fuller, more traditional cup. The difference in body and aromatics between paper and cloth on a syphon is more noticeable than on any other brew method.
What You Need
Equipment
Brewer
Syphon Brewer
Hario Technica, Yama, or Hario Next are the most reliable. 2, 3, or 5 cup sizes available. Always use borosilicate glass.
Heat Source
Beam Heater or Burner
Halogen beam heater gives the most control and is safest for home use. Butane burner heats faster. Alcohol burner is traditional but slowest.
Filter
Cloth, Paper, or Metal
See filter section above. Have the correct size filter for your brewer model. Filter size is not universal across brands.
Grinder
Burr Grinder
Medium grind, similar to drip coffee. Slightly coarser than V60. Consistent grind is important for the immersion phase extraction.
Scale
0.1g Precision
Weigh coffee and pre-measured water. The syphon does not allow mid-brew adjustment, so precision before the brew matters more.
Stirring Paddle
Bamboo or Silicone
Included with most syphon sets. Bamboo is traditional. Never use metal near the glass chambers. Stir technique directly affects extraction.
The Recipe
Starting Ratios
The syphon uses a slightly lower coffee-to-water ratio than most pour over methods because the full immersion at elevated temperature extracts more efficiently. A 1:13 to 1:15 ratio works best. The recipe below is for a standard 3-cup syphon, which produces approximately 360ml of brewed coffee.
25g
Coffee
Medium grind
360ml
Water
Pre-measured cold or hot
1:14
Ratio
Full bodied, aromatic
90 sec
Immersion
After water rises
The immersion time , the period when coffee and water are in contact in the upper chamber , is your primary extraction control in syphon brewing. Unlike pour over methods where you adjust grind and pour technique, on the syphon you adjust immersion time and stir technique. A standard immersion of 60 to 90 seconds produces a balanced, full cup. Extending to 2 minutes adds body but risks bitterness. Reducing to 45 seconds produces a lighter, brighter cup more similar to pour over in character.
Water temperature in the upper chamber during immersion typically sits between 88 and 92°C because the water cools slightly as it rises from the lower globe. This temperature range is ideal for most roast levels without requiring adjustment. The syphon is one of the few brew methods that largely self-regulates temperature during extraction.
The Brew Cycle
Understanding the Four Phases
The syphon brew cycle has four distinct phases. Knowing what to expect and what to do at each phase is the foundation of good syphon technique.
Phase 1
Heating
Water heats in the lower globe
Heat builds pressure until water begins to rise up the syphon tube. You will see small bubbles forming and water beginning to move upward. This phase takes 3 to 7 minutes depending on your heat source and whether you started with cold or pre-heated water.
Phase 2
Rise
Water moves into the upper chamber
Hot water rises through the tube and floods the upper chamber where your grounds are waiting. The water should arrive at around 88 to 92°C. As water rises, stir immediately to ensure all grounds are saturated evenly. This is your first and most important stir.
Phase 3
Immersion
Coffee steeps in the upper chamber
Maintain heat to keep water in the upper chamber. Coffee and water steep together for 60 to 90 seconds. Stir gently at the midpoint of the immersion to redistribute the grounds. Monitor the slurry surface: it should be calm and even, not turbulent or rapidly bubbling.
Phase 4
Draw Down
Vacuum pulls brew into lower globe
Remove the heat source. The lower globe cools rapidly and the vacuum draws the brewed coffee back down through the filter. The drawdown should complete in 30 to 60 seconds, leaving a clean, domed bed of spent grounds in the upper chamber. A dome means the vacuum worked correctly.
The Method
Step by Step
1
Prepare the Filter
Attach the filter to the bottom of the upper chamber using the metal hook or chain. The filter must sit centred and flat over the opening at the base of the upper chamber tube. If using a cloth filter, soak it in hot water for 2 minutes before use to remove any dry or musty character and ensure full flow through the fabric. If using paper, rinse under hot water for 30 seconds. Pull the chain gently to confirm the filter is secured and will not shift during the brew.
Centre the filter precisely. An off-centre filter allows grounds to bypass the filtration zone during drawdown, resulting in sediment in your cup. Pull the hook gently from below the tube after attaching to seat the filter perfectly flat against the glass.
2
Add Water to the Lower Globe
Measure 360ml of water and add it to the lower globe. You can use cold water, but starting with hot water from a kettle reduces total brew time by 3 to 4 minutes and reduces the period during which the glass is exposed to extreme heat differential. Dry the outside of the lower globe thoroughly before placing it on the heat source: water droplets on hot glass cause thermal stress and, over time, cracking.
Always dry the outside of the globe. This is a safety and longevity habit. Water on the exterior of borosilicate glass during heating creates localised thermal stress points. Dry it every single time before applying heat.
3
Grind and Stage the Coffee
Grind 25g of coffee to a medium grind: slightly coarser than V60, similar to drip coffee or a coarser AeroPress grind. Add the ground coffee to the upper chamber and set it loosely on top of the lower globe without fully sealing the joint. You will seal it completely once the water begins to rise. Staging the upper chamber in this way allows steam to escape from the lower globe as it heats, preventing pressure buildup before you are ready.
4
Apply Heat and Seal
Apply your heat source to the lower globe at medium-high setting. Watch the water closely. As small bubbles begin to form and water starts showing movement toward the tube, press the upper chamber down firmly to create a full seal with the rubber grommet. The seal must be airtight for the vacuum to function correctly during drawdown. A loose seal means the vacuum will fail and the coffee will not return to the lower globe cleanly.
Seal before the water rises, not after. If you wait until water is already moving up the tube to seal the upper chamber, you will trap steam and create uneven pressure. Seal as the first significant bubbles form in the lower globe, before the rise begins.
5
First Stir as Water Rises
As hot water floods into the upper chamber, immediately use your bamboo paddle to stir the slurry in a gentle figure-eight or circular motion for 5 to 10 seconds. The goal is to ensure every coffee particle is fully saturated and no dry grounds remain floating on the surface. This first stir is the most important of the entire brew: uneven saturation at this stage produces uneven extraction throughout the immersion. Reduce heat slightly to maintain a gentle simmer in the lower globe without aggressive bubbling.
6
Immersion: 60 to 90 Seconds
Maintain gentle heat to keep the water in the upper chamber. The slurry surface should be calm and steady, not vigorously bubbling. At the 45-second mark, give the slurry a second gentle stir: 3 to 5 slow circular passes with the paddle, just enough to redistribute the grounds without introducing excessive turbulence. This mid-immersion stir promotes even extraction across the full depth of the coffee bed. After your second stir, let the final 15 to 30 seconds of immersion proceed undisturbed.
Stir technique matters. Aggressive stirring creates turbulence that fragments the grounds and pushes them against the filter, slowing drawdown and potentially passing fines through. Gentle, deliberate strokes are always correct on a syphon. Think of stirring as guiding the coffee, not agitating it.
7
Remove Heat and Draw Down
At 60 to 90 seconds of immersion, remove the heat source completely. The lower globe will begin cooling immediately. Within 10 to 20 seconds, the vacuum effect will pull the brewed coffee back down through the filter and into the lower globe. Watch the drawdown: it should be steady and complete within 30 to 60 seconds. The spent grounds in the upper chamber will form a clean dome shape as the last liquid is pulled through. A dome is a sign of a successful, even brew. A flat or uneven ground bed indicates uneven extraction.
8
Remove Upper Chamber and Serve
Once drawdown is complete, gently twist and remove the upper chamber. Place it on the stand or a heat-safe surface. Give the brewed coffee in the lower globe a gentle swirl to integrate any temperature variation between the first and last liquid drawn down. Pour immediately into pre-warmed cups. Syphon coffee is best served within 5 minutes of completion: the aromatic compounds that make syphon coffee exceptional are volatile and dissipate quickly. Do not let it sit.
Serve immediately. The aromatics in syphon coffee are more volatile than in any other brew method. The window between extraordinary and ordinary is short. Have your cups warm and ready before you start the brew.
Diagnose Your Cup
Variables and Troubleshooting
Problem
Coffee Does Not Draw Down
Seal between upper and lower chamber is not airtight. No vacuum forms so coffee remains in the upper chamber after heat is removed.
Check the rubber grommet for cracks or wear. Ensure upper chamber is firmly pressed and sealed before the water rises. Replace grommet if damaged.
Problem
Drawdown is Very Slow
Grind too fine clogging the filter, cloth filter needs cleaning, or grounds pushed hard against filter during aggressive stirring.
Grind coarser. Clean cloth filter thoroughly. Stir more gently during immersion. Replace cloth filter if it is more than 3 months old.
Problem
Sediment in the Cup
Filter not centred correctly in the upper chamber, allowing grounds to bypass the filter during drawdown.
Re-seat the filter by pulling the hook to centre it precisely. Use paper filter for finer filtration if the problem persists with cloth or mesh.
Problem
Bitter, Over-Extracted Cup
Immersion time too long, heat too high during immersion causing temperature above 94°C in upper chamber, or grind too fine.
Reduce immersion to 60 seconds. Lower heat to maintain a gentle simmer only. Grind coarser by 2 to 3 clicks.
Problem
Weak, Thin Cup
Immersion time too short, grind too coarse, or poor first stir leaving dry grounds unsaturated during the extraction phase.
Extend immersion to 90 seconds. Grind finer. Ensure the first stir fully saturates all grounds the moment water arrives in the upper chamber.
Problem
Flat, Dull Aromatics
Coffee is stale, cup not pre-warmed so aromatics condense on cold glass, or brew was left to sit too long before serving.
Use coffee within 2 weeks of roast date. Pre-warm cups with hot water. Serve immediately after drawdown completes.
The Brewer You Brew
When Coffee is the Point
I do not recommend the syphon as an everyday brewer. It takes time, it takes attention, and it takes cleaning. But for certain occasions and certain coffees, nothing else comes close. The aromatic intensity of a well-executed syphon brew is genuinely different from every other method. The vacuum draws something out of the coffee that immersion alone or percolation alone does not. You smell it before you taste it and the smell is extraordinary.
The coffees that work best on a syphon are ones with complex, layered aromatics: washed Ethiopians with jasmine and bergamot, naturally processed Yemenis with dried fruit and spice, high-altitude Guatemalans with chocolate and stone fruit. The syphon amplifies aromatic volatiles more than any other brew method. Put a great coffee through it and the cup is a genuine experience. Put a flat, stale coffee through it and the method will not save you.
One practical recommendation: if you are buying a syphon, invest in a halogen beam heater rather than the alcohol or butane burner. The beam heater gives you precise, adjustable, consistent heat that is safe on any surface and easy to control during the immersion phase. Butane burners heat faster but the heat is harder to regulate at the lower levels needed during immersion. The alcohol burner is traditional and beautiful but the slowest and least controllable of the three. For most home setups the beam heater is the right choice.
The Syphon Principle
"Use the syphon when coffee deserves your full attention. The right coffee, the right technique, and a warm cup ready before you start. That is when it becomes something special."
Quick Reference
Syphon at a Glance
Coffee Dose
20 – 30g
25g for 3-cup syphon
Water Volume
360ml
Per 3-cup brew
Brew Temp
88 – 92°C
Self-regulates in upper chamber
Grind Size
Medium
Slightly coarser than V60
Immersion
60 – 90 sec
After water fully rises
Ratio
1:14
Full bodied and aromatic
Brew Checklist
Soak cloth filter or rinse paper filter before brewing
Centre filter precisely using the hook
Dry outside of lower globe before heating
Seal upper chamber before water rises
Stir immediately and thoroughly as water arrives
Stir gently at 45 seconds during immersion
Remove heat at 60 to 90 seconds
Serve immediately into pre-warmed cups