Piston Coffee Dosage: 7g per 100ml (Table + Calculator)

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Maxime Duhamel

Coffee Expert and Consultant

15 years of expertise

A coffee enthusiast for over 15 years, I’m dedicated to sharing my in-depth knowledge of the art and science of coffee. From bean selection to roasting and preparation techniques, I explore every aspect of this fascinating beverage to help you discover the best of coffee.

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15 years of experience

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Is your coffee too bitter, too light or simply bland? The problem lies in your dosage.

The universal golden rule: 7 grams of ground coffee per 100ml of water (i.e. 60-70g per 1 litre).

In this guide, you will discover :

• The exact dosage table for your coffee maker
• A simple calculator so you can never go wrong
• How to adjust to your tastes
• Mistakes that ruin your coffee

Reading time: 5 minutes | Time for a perfect coffee: 4 minutes

Coffee Piston Dosage Chart (Printable)

Use this table as a cheat sheet for dosing without scales:

📌 Quick reminder :

• 1 heaped tablespoon = 10-12g ground coffee
• Universal ratio = 1:14 (1g of coffee to 14ml of water)
• Mandatory grind: Coarse (coarse salt)

Mental Express calculator (without scales)

Don’t have a scale? Use this formula in 3 seconds:

📐 The Magic Formula

Volume of your coffee maker (ml) ÷ 14 = Grams of coffee

Concrete examples:

• 350ml coffee pot → 350 ÷ 14 = 25g of coffee
• 500ml coffee pot → 500 ÷ 14 = 35g of coffee
• 800ml coffee pot → 800 ÷ 14 = 57g of coffee
• 1L coffee maker → 1000 ÷ 14 = 71g of coffee

💡 Intensity adjustment :

• LIGHTER coffee → divide by 15 instead of 14
• HEAVIER coffee → divide by 13 instead of 14

Soup Spoon Conversion (Without Scale)

Precise Equivalences

1 tablespoon ground coffee = 1 tablespoon ground coffee = 1 tablespoon ground coffee

• Curved: 10-12 grams
• Shave: 7-8 grams

1 teaspoon =

• Domed: 3-4 grams

Fast dosing by size

🎯 Visual tip: The ground coffee should form a 1 to 1.5 cm layer at the bottom of your empty coffee maker.

The Perfect Recipe in 7 Steps (4 Minutes)

✅ STEP 1: Dosage of coffee (30 seconds)

For 1 litre of water :

• Weigh out 70 grams of coarse ground coffee
• OR 7 heaped tablespoons

Required grind: Coarse as coarse salt (not fine as flour)

💡 No mill? Find out how to grind without equipment →

✅ STEP 2: Heat the water (3 minutes)

Ideal temperature: 92-95°C

Without thermometer :

1. Boil the water (100°C)
2. Wait 30-40 seconds
3. It will be at 92-95°C

Type of water: Filtered if possible (avoid hard water)

✅ STEP 3: Preheat the coffee maker (10 seconds)

1. Rinse inside with hot water
2. Empty completely
3. Add the ground coffee

What’s the point? To avoid the thermal shock that cools the infusion.

✅ STEP 4: Pour and mix (20 seconds)

1. Pour the hot water in a circular motion
2. Mix gently for 10 seconds with a spoon
3. Fit the cover (piston in UP position)

Objective: All the coffee should be well moistened.

✅ STEP 5: Infusion (4 minutes)

⏱️ Set your timer for exactly 4 minutes

• Café LÉGER → 3 minutes
• ÉQUILIBRÉ coffee → 4 minutes
• Coffee CORSÉ → 5 minutes

🚫 Do not touch ANYTHING during brewing.

✅ STEP 6: Pro “Casser la Croûte” technique (30 seconds – OPTIONAL)

3min30 from brewing:

1. Remove the cover
2. Using a spoon, gently break the crust that has formed on the surface.
3. Remove the foam with the spoon
4. Wait 30 seconds for the residue to fall off

Result: Clearer coffee, less grounds in the cup.

✅ STEP 7: Press and serve (30 seconds)

1. Lower the piston VERY SLOWLY (count 20-30 seconds)
2. If strong resistance → your grind is too fine
3. Serve IMMEDIATELY in pre-warmed cups

⚠️ GOLDEN RULE: NEVER leave the coffee to stand in the coffee maker after pressing. It will continue to brew and become bitter. Transfer to a thermal carafe if you’re not serving immediately.

SOS Café Raté: The 4 Problems and Solutions

❌ Problem 1: Coffee too light / No taste

Symptoms :

• Pale, transparent colour
• Watery, bland taste
• No body in the mouth

✅ Immediate solutions:

1. Increase the coffee → Add 10g (1 spoonful)
2. Check the temperature → Water at least 92°C
3. Increase the infusion time → Increase from 4 to 5 minutes
4. Refine the grind → A little less coarse (but not fine!)

Test: Your coffee should be opaque dark brown and leave a trace on the cup.

❌ Problem 2: Coffee too bitter

Symptoms :

• Persistent unpleasant aftertaste
• Dry mouth
• Burnt or metallic taste

✅ Immediate solutions:

1. Reduce the coffee → Remove 10g
2. Lower the temperature → Wait 45s after boiling (88°C)
3. Shorten the infusion → Go from 4 to 3 minutes
4. Check the grind → Must be COARSE

💡 Tip: Some coffees are naturally less bitter. Discover the best non-bitter coffee beans →

Common cause: Pre-ground supermarket coffee = often too fine for the piston.

❌ Problem 3: Troubled coffee with residue

Symptoms :

• Coffee grounds in the cup
• Unpleasant grainy texture
• Opaque coffee

✅ Immediate solutions:

1. Coarser grind → Cause #1 of the problem
2. Slow down the descent → Minimum 30 seconds to press
3. Crust” technique → Remove the foam before pressing
4. Check the seal → Must be clean and correctly positioned

Visual cue: The grind should look like gravel, not flour.

❌ Problem 4: Inconsistent result

Symptoms :

• Yesterday perfect, today a failure
• Impossible to reproduce the same taste
• Sometimes too strong, sometimes too light

✅ Definitive solution: THE BALANCE

Invest £15 in a kitchen scale. It’s THE change that will transform your coffee.

Routine consistency:

1. Weigh the coffee AND the water each time
2. Use a timer (4 minutes precise)
3. Same coffeemaker, same temperature
4. Write down your ideal recipe

Result: After 3-4 coffees, you’ll be able to reproduce YOUR perfect dosage every morning.

Adjust to Your Tastes (Progressive Method)

🥉 Beginner level : Safe dosing

Objective: Get it right first time, without risk.

Basic recipe :

• 70g of coffee for 1L of water
• Coarse grinding
• Infusion time 4 minutes
• Water at 92°C

Tip: Use this same recipe 5 times in a row before changing anything. That way you’ll have a reliable reference.

🥈 Intermediate level: Customisation

Objective: Adjust to your preferences.

Diagnostic grid :

💡 Pro tip: Take a photo of your packet of coffee with the dosage that worked. Every origin reacts differently:

• Light Ethiopian coffee → 75g/L
• Full-bodied Robusta → 60g/L

📖 Going further: What type of coffee to choose for your piston →

🥇 Expert level: Complete mastery

Objective: To interact with your coffee and extract the best from it.

Adjustment according to origin

Adjustment according to roast

The “Bloom” Technique (Pre-infusion)

1. Pour just 50ml of hot water over the coffee
2. Wait 30 seconds for the aromas to “flower”.
3. Pour in the rest of the water and continue as normal

Result: More homogeneous extraction, more complex aromas.

The Equipment That Changes Everything (Budget €15-150)

🏆 Investment #1: Precision Scale (15-30€)

Impact on your coffee: 10/10

Why it’s essential:

• Dosage to the nearest gram
• Perfect reproducibility
• The end of approximations

What you need :

• Accuracy: 1 gram is enough
• Capacity: Minimum 500g
• Tare function (reset to zero)
• Price: €15-20 on Amazon

Recommended models :

• Amazon Basics kitchen scale (£15)
• Hario V60 Drip Scale (€50 – with timer)

⚙️ Investment #2: Coffee grinder (€40-150)

Impact on your coffee: 9/10

Pre-ground coffee loses 60% of its aroma in 15 days. Grind just before brewing = incomparably better coffee.

Option A: Manual Mill (€40-60)

✅ Advantages :

• Economical
• Silencer
• Perfect for 1-2 people
• Precise control

❌ Disadvantage:

• Physical effort (2-3 min cranking)

Recommended models :

• Hario Mini Mill (€40)
• Porlex Mini (€50)

Option B: Electric Grinding Mill (€100-150)

✅ Advantages :

• Fast and effortless
• Regular grinding
• Several settings

❌ Disadvantages:

• Noisier
• Higher investment

Recommended models :

• Melitta Calibra (€100)
• Wilfa Svart Aroma (€150)

⚠️ AVOID: Mills with blades (like spice grinders). They chop unevenly and create heat which alters the flavours.

🔥 Investment #3: Temperature kettle (€40-80).

Impact on your coffee: 6/10

Option A: Classic kettle (Free)

Technique: Boil, then wait 30-40 seconds.

Option B: Adjustable kettle (€40-80)

Advantages :

• Precise temperature (85°C, 90°C, 95°C)
• Temperature maintenance
• Handy if you also make tea

Recommended models :

• Aigostar King (€40)
• Bosch TWK8613P (80€)

💰 Summary by Budget

Our advice: Start with the €15 scales. It will have the most immediate impact.

Frequently asked questions (FAQ)

❓ How many grams of coffee for 500ml of water?

Answer: 35 grams (or 3 heaped tablespoons)

Calculation: 500ml ÷ 14 = 35g

❓ How much coffee for 1 litre of water in a piston coffee maker?

Answer: 60 to 70 grams (or 6-7 heaped tablespoons)

• Light coffee: 60g
• Balanced coffee: 70g
• Strong coffee: 80g

❓ Can fine ground coffee be used in a piston coffee maker?

No, that’s the most common mistake.

Fine grind = over-extraction = bitter coffee + residue in the cup.

Solution: Coarse grind required (like coarse sea salt).

❓ How long does it take to brew a piston coffee?

Answer: 4 minutes is the standard.

• Light coffee: 3 minutes
• Balanced coffee: 4 minutes
• Strong coffee: 5 minutes

Maximum recommended: 5 minutes. After that, the bitterness dominates.

❓ What water temperature for a piston coffee maker?

Answer: 92-95°C is the ideal range.

Without a thermometer: Bring to the boil, then wait 30-40 seconds.

Why not 100°C? Boiling water burns the coffee and creates bitterness.

❓ Can piston coffee be reheated?

No, not in the microwave.

Reheated coffee loses its aroma and becomes bitter.

Solution: Pour the coffee into a thermal carafe after brewing. It will stay hot for 2-3 hours with no change in flavour.

❓ How many cups with 1 litre of water?

Answer: 6 to 8 cups, depending on the size of the cups.

• Small cup (120ml): 8 cups
• Medium cup (150ml): 6-7 cups
• Mug (250ml) : 4 mugs

❓ Should the coffee be rinsed before brewing?

No, it’s not necessary, and it’s not even advisable.

The ‘bloom’ (pre-infusion with 50ml of water) is enough to release the aromas.

Rinsing = loss of soluble aromas.

❓ Coffee beans or ground coffee for plunger coffee maker?

Freshly ground coffee beans = always better.

Ground coffee loses 60% of its aroma in 15 days.

If you don’t have a grinder: Buy coffee specially ground for piston coffee makers (coarse grind). Avoid “universal” coffee that is too fine.

Conclusion: Your Perfect Coffee in 3 Actions

You now have all the keys you need to make a successful plunger coffee every time.

🎯 Remember the essentials:

1. The golden rule: 7g of coffee per 100ml of water
(i.e. 70g for 1 litre)

2. The 3 pillars of perfect coffee :

• ✅ Precise dosing (invest in a €15 scale)
• ✅ Coarse grind (like coarse salt)
• ✅ Constance (same recipe = same result)

3. Your immediate action plan :

• [ ] Print the dosing table
• [ ] Test the basic recipe (70g/L, 4 min, 92°C)
• [ ] Write the result in a notebook
• [ ] Adjust by ±10g to taste
• [ ] Buy a kitchen scale (€15)

💡 The final secret

The perfect dosage doesn’t exist in the absolute, it exists for YOU. It’s the one that makes you say “ah, that’s exactly how I like it” every morning.

Experiment without fear, note down your results, and in a few weeks you’ll be your own expert barista.