Switching to a bottomless portafilter is a game-changer — it’s satisfying, educational, and can seriously level up your espresso game. It helps you see exactly how your espresso is extracting — but that also means it reveals every inconsistency in your technique.
At the beginning, using a bottomless portafilter may require some adjustments to your grind size, dosage, or overall prep technique.
If you’re seeing wild spurts, messy shots, or inconsistent flow, don’t panic — it’s completely normal. Let us walk you through how to identify the issue and fix it.
(This also applies to customers using our double-spout portafilter who notice their shots are running too fast, spurting, or creating a mess.)
✅ Step 1: Make Sure the Portafilter Fits Your Machine
Before diagnosing any extraction issues, it’s important to confirm that the portafilter is the correct fit for your coffee machine:
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Check our compatibility list to ensure your machine model is supported.
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Confirm that the item you received matches your order.
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Lock the portafilter into your group head and check for water leaking from the top seal when brewing.
If there’s no water leaking from the group head and the issue is spurting from the bottom of the portafilter, then the portafilter is working as it should. It’s not defective — it’s simply highlighting areas where your espresso prep may need improvement.
💥 What Causes Spurting or Channeling?
Spurting or “channeling” usually happens because of uneven water flow through the coffee puck. This can lead to a messy shot, uneven crema, or sour/bitter taste.
Here are the most common causes:
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Improper Dosing
Too little coffee leaves gaps in the puck, while too much can cause resistance and lead to blowouts. -
Incorrect Grind Size
If your grounds are too coarse or clumpy, water flows through too quickly. If they’re too fine, pressure builds excessively and causes spurting. -
Uneven Distribution
Grounds that aren’t evenly spread allow water to punch through weak spots, creating channeling. -
Inconsistent Tamping
A tilted or uneven tamp leads to uneven resistance, disrupting the flow.
🛠️ How to Fix It
Here’s how to clean up your shots and get better extractions:
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Weigh Your Dose
Use a scale and match your dose to your basket size — for example, use 18g in an 18g basket. This ensures consistency. -
Dial In Your Grind
We don’t recommend using pre-ground coffee, as it limits your ability to fine-tune the grind.
Start with your usual grind setting.-
Go finer if the shot flows too fast or spurts.
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Go coarser if it chokes or runs too slowly.
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Use a WDT Tool
A WDT (Weiss Distribution Technique) tool helps break up clumps and ensures the grounds are evenly spread in the basket. -
Try a Distribution Tool
This levels the surface of the puck for consistent density across the entire bed. -
Tamp Evenly
Apply firm, level pressure with a flat tamper. Avoid tilting, as uneven tamping causes uneven flow. -
Check the Results & Adjust
After completing the steps above, it's time to test and fine-tune:
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If the shot still runs fast, try pulling another one — sometimes tamping inconsistencies can cause variations.
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If multiple shots run fast, adjust your grind to a finer setting and try again.
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If the shot runs too slowly or doesn’t flow at all, switch to a slightly coarser grind.
Repeat the process until you achieve a shot you're happy with — balanced flow, rich crema, and great taste.
Once you've dialled in the right grind size and recipe for your coffee, your portafilter will consistently deliver delicious, café-quality espresso.
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🤔 “But This Didn’t Happen With My Old Portafilter…”
That’s a common concern — and a great question.
If you're seeing spurting or faster flow with your new bottomless or double-spout non-pressurised portafilter, but everything seemed fine with your old one, here’s what’s likely happening:
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Your previous portafilter likely used a pressurised basket, which is designed to be more forgiving. It builds artificial pressure and hides inconsistencies in grind size, tamping, or distribution — even pre-ground coffee can work reasonably well.
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In contrast, non-pressurised baskets (like those used in bottomless or upgraded double-spout portafilters) require more precision and rely on a well-prepared puck to extract properly. These baskets reveal issues — they don’t hide them.
⚖️ Basket Size & Dose Also Matter
Compared to your previous portafilter, the basket size and shape may be different. Most upgraded portafilters come with a larger-capacity basket (typically 18g) that holds more coffee than the standard pressurised ones.
This means:
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The grind size and dosage you used with your old setup may not be suitable anymore.
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You’ll likely need to grind finer, increase your dose, or adjust your prep to get optimal results.
Final Thoughts
A bottomless or upgraded portafilter doesn’t just improve your espresso — it improves your skills. It may take a few messy shots to get things right, but once dialled in, it becomes an essential tool for pulling rich, consistent, and café-quality espresso at home.