DIY Coffee Ink: A Natural Writing and Art Medium

Quick answer

• Gather stale coffee grounds or leftover brewed coffee.
• Mix grounds/coffee with water, simmer, and strain.
• Add a binder like gum arabic or cornstarch for permanence.
• Test ink consistency and color.
• Store in an airtight container.
• Experiment with different coffee types and roast levels.

Who this is for

• Artists looking for affordable, natural art supplies.
• Writers and journalers who want a unique, eco-friendly ink.
• DIY enthusiasts eager to craft their own creative materials.

What to check first

Brewer Type and Filter Type

This matters less for the ink itself, but how you got the coffee originally can influence the starting material. Drip coffee makers, French presses, even espresso machines all yield different grounds or liquid. The filter used (paper, metal) might leave trace elements, but for ink, it’s usually not a big deal.

Water Quality and Temperature

Tap water is generally fine for making coffee ink. If your tap water tastes funky, your ink might too. For brewing the ink, simmering is key. You don’t need boiling, just a gentle heat to extract the color and flavors. Think cozy stovetop, not a raging inferno.

Grind Size and Coffee Freshness

This is more important. Finer grounds (like for espresso) will release more pigment. Coarser grounds (French press) will still work but might yield a lighter shade. Stale grounds or leftover cold brew are perfect. You’re not trying to extract peak flavor, just color.

Coffee-to-Water Ratio

This is your main lever for ink strength. More coffee grounds or stronger brewed coffee means a darker, richer ink. Start with a ratio that feels about right – maybe 1:1 coffee grounds to water, or a strong brewed coffee concentrate. You can always add more water to thin it out later.

Cleanliness/Descale Status

Make sure your pots and strainers are clean. You don’t want old coffee oils or residue messing with the new ink’s color or smell. A quick rinse is usually enough, but if you’re making a lot, a good scrub won’t hurt.

Step-by-step (brew workflow)

1. Gather your coffee. Grab those stale grounds from the back of the cupboard or that half-full mug of cold brew.

• What good looks like: A decent pile of used grounds or a cup of leftover coffee.
• Common mistake: Using fresh beans. You’re not brewing a latte here. Save those for drinking.

2. Combine coffee and water. If using grounds, mix them with water in a saucepan. If using brewed coffee, pour it into the pan. A good starting point is equal parts grounds and water, or a 1:1 ratio of brewed coffee to fresh water.

• What good looks like: A slurry or liquid in the saucepan, ready for heating.
• Common mistake: Using too little water. It’ll get too thick too fast and might scorch.

3. Simmer gently. Heat the mixture over low to medium-low heat. You want it to gently bubble, not boil aggressively. Stir occasionally.

• What good looks like: A steady, low simmer. Steam rising, color deepening.
• Common mistake: Boiling hard. This can evaporate the water too quickly and burn the coffee solids.

4. Extract the color. Let it simmer for 15-30 minutes, or until the liquid looks like a rich, dark coffee. The longer it simmers, the more pigment you’ll get.

• What good looks like: The water has turned a deep brown, much darker than regular coffee.
• Common mistake: Not simmering long enough. You’ll end up with a weak, pale ink.

5. Cool slightly. Remove the saucepan from the heat and let it cool down enough to handle safely.

• What good looks like: Warm to the touch, but not scalding.
• Common mistake: Trying to strain piping hot liquid. You risk burns and messy spills.

6. Strain the liquid. Pour the mixture through a fine-mesh sieve lined with cheesecloth or a coffee filter into a clean bowl or jar. Squeeze out as much liquid as you can.

• What good looks like: A dark liquid is collected, leaving the coffee solids behind.
• Common mistake: Not straining well. Little coffee particles will clog your pens later.

7. Add a binder (optional but recommended). For a more permanent ink that won’t smudge easily, stir in a binder. Gum arabic (about 1-2 tablespoons per cup of liquid) or a bit of cornstarch (dissolved in a little cold water first) works well.

• What good looks like: The liquid might thicken slightly. It should still flow.
• Common mistake: Adding binder to hot liquid. It can clump. Let it cool first.

8. Test and adjust. Dip a brush or pen into the ink. See if the color and consistency are what you want. Add more water to thin it, or simmer a bit longer (if you didn’t add binder yet) to deepen the color.

• What good looks like: The ink flows nicely and the color is rich.
• Common mistake: Not testing. You might end up with ink that’s too thick, too thin, or too pale.

9. Store properly. Pour the finished ink into an airtight glass bottle or jar. Store it in a cool, dark place.

• What good looks like: The ink is sealed in its container, ready for use.
• Common mistake: Leaving it open. It will dry out or get contaminated.

Common mistakes (and what happens if you ignore them)

Mistake	What it causes	Fix
Using fresh coffee grounds	Wasted good coffee, less pigment extraction	Use stale grounds or leftover brewed coffee.
Boiling aggressively	Scorched coffee solids, bitter taste (if relevant)	Simmer gently over low heat.
Not straining thoroughly	Clogged pens, gritty writing/art	Use a fine-mesh sieve and cheesecloth or coffee filters.
Skipping the binder	Ink smudges easily, not permanent	Add gum arabic or cornstarch for better adhesion.
Adding binder to hot liquid	Clumpy binder, uneven consistency	Let the liquid cool before adding binder.
Storing in an unsealed container	Ink dries out, gets moldy, or contaminated	Use an airtight glass bottle or jar.
Using too much water initially	Weak, pale ink that requires excessive simmering	Start with a stronger concentration and thin as needed.
Not testing consistency before storage	Ink is too thick or too thin for intended use	Dip a brush or pen in the ink to check flow before storing.
Using dirty equipment	Off-flavors or colors, potential spoilage	Ensure all pots, strainers, and containers are clean.
Forgetting about roast level	Different shades and tones than expected	Experiment with light, medium, and dark roasts for varied results.

Decision rules (simple if/then)

• If your ink is too pale, then simmer it longer because more time will extract more pigment.
• If your ink is too thick, then add a little more water because you can always thin it down.
• If your ink is too thin, then simmer it uncovered to reduce the water content because evaporation will concentrate the color.
• If your ink smudges easily, then you likely need a binder because binders help the pigment adhere.
• If you want a darker shade, then use more coffee grounds or a darker roast because these have more pigment.
• If you want a lighter shade, then use less coffee or dilute with more water because this reduces the pigment concentration.
• If your ink has a weird smell, then check your equipment for old residue or make sure the coffee wasn’t rancid because clean gear is key.
• If you’re using this for dip pens, then ensure it’s not too thick or it might not flow well because flow is crucial for dip pens.
• If you want a more permanent, watercolor-like effect, then consider adding a bit more binder like gum arabic because it creates a more stable film.
• If your ink seems to be separating, then give it a good shake before use because coffee can sometimes settle.

FAQ

Can I use instant coffee?

Yeah, you can try it. Instant coffee is already concentrated, so you might just need to dissolve it in a bit of hot water. The color might be different than grounds, though.

How long does coffee ink last?

Stored properly in an airtight container in a cool, dark place, it can last for months, even up to a year. Keep an eye out for any mold or funky smells, though.

What kind of coffee is best?

Darker roasts generally give a richer, deeper color. But don’t be afraid to experiment with different roasts and even types of beans to see what shades you get.

Can I make different colors?

Not really with just coffee. Coffee ink is naturally brown. You could potentially mix it with other natural pigments if you get into that, but on its own, it’s a brown ink.

What pens can I use with coffee ink?

Dip pens and fountain pens with wider nibs usually work best. Avoid very fine-tipped pens or those with tight ink feeds, as the coffee solids might clog them.

Does it smell like coffee?

It will have a subtle coffee aroma, especially when wet. It’s usually a pleasant, mild scent, not overpowering.

What if I don’t have gum arabic?

Cornstarch is a decent substitute. Dissolve a teaspoon or two in a tablespoon of cold water, then stir that slurry into your cooled coffee ink. It might make the ink a bit more opaque.

Is this ink waterproof?

Not entirely, especially if you don’t use a binder. Even with a binder, it’s more water-resistant than truly waterproof. It might feather or run if it gets very wet.

What this page does NOT cover (and where to go next)

• Advanced ink modification techniques (e.g., adding other natural dyes for color).
• Specific brand recommendations for coffee beans or binders.
• Detailed archival testing for lightfastness and longevity.
• Using coffee ink with specific art techniques like calligraphy or bookbinding.