Vegan Leather From Coffee Waste | Biodesign Material Trial

We aimed to create a biodegradable and flexible material resembling vegan leather using coffee waste, agar agar, starch, vinegar, and glycerin.

This project is part of a biodesign research course where the goal was to develop material alternatives from food waste.

SUPPLIES

1. 200 ml water
2. 1 tsp agar agar
3. 2–3 tbsp corn starch (added gradually, including extra for texture)
4. 15 g used filter coffee grounds (freshly ground, not capsule-based)
5. 2 tsp glycerin
6. 1 tsp white vinegar
7. Glass beaker or heat-resistant jar
8. Spatula
9. Precision scale
10. Stirring rod or spoon
11. Hot plate or stove
12. Acrylic mold (for sheet formation)
13. Oven (set to 35°C for drying)
14. (Optional: thermometer for temperature control)

Collected used coffee pods from household environments and dried them in an oven for a few minutes to remove any remaining moisture.

2.

Gathered all the materials and brought them together in a laboratory setting for the experiment.

(image labels: hot plate, beaker, distilled water, wheat starch, agar agar, glycerin, vinegar, used coffee grounds, stirrer, thermometer, precision scale, spatula)

3.

Water was poured into a beaker and mixed with agar agar.

4.

Wheat starch and the coffee grounds, which we had measured using a precision scale, were added to the mixture.

5.

Finally, using the precision scale, vinegar and glycerin were added to the mixture.

6.

Mixed the entire solution until it reached a homogeneous stage.

Some materials were added later in amounts above the expected weight, depending on the consistency.

7.

Then, the mixture was placed on hot plate and stirred continuously until it began to gel and reached a honey-like consistency.

8.

Finally, the mixture was removed from the hot plate and temperature was measured.

Once it began to cool slightly, it was poured into shaped molds, leveled, and left to dry.

1.

200 ml water was poured into a glass beaker.

🍬 1 tsp agar agar was added and mixed until dissolved.

🌿 This time, more starch was added to achieve better consistency.

2.

15 g of filter coffee grounds were added and stirred continuously.

We used freshly ground filtered coffee instead of capsule coffee to improve texture.

3.

Heated the mixture over low heat for 5 minutes, stirring constantly.

4.

Added 2 tsp glycerin and 1 tsp vinegar for flexibility and binding.

This time, vinegar ratio was slightly increased for stronger bonding.

5.

🔥 Heated the mixture over low heat for 5 minutes, stirring constantly.

🍮 Ideal thickness: pudding-like, sticky but not breaking.

6.

After the initial heating, we added extra corn starch to enhance the thickness.

🌱 This time, we first dissolved starch in water, then added more dry starch separately for better firmness and structure.

7.

🔒 The final mixture was poured into an acrylic mould.

🥄 It was spread evenly with a spatula, aiming for a 4–5 mm thickness.

8.

30 minutes at 35°C for gradual water release.

🔥 Full drying for 24 hours in the oven at stable low temperature.

⭐ FINAL RESULT

The final sample achieved a uniform texture, flexibility, and clean peel-off from the mold — very close to leather-like behavior.

🔁 PHASE 1 & PHASE 2 – Differences from First Trial

1. ☕ Used filter coffee instead of Nespresso capsule grounds → finer texture, less oil residue
2. 🟢 Increased starch content significantly → firmer and more cohesive material
3. 🍋 Higher vinegar ratio → improved bonding and acidity balance
4. 🔥 Oven-dried for 24h instead of room drying → faster process, no mold formation