Uploaded April 2021 | Updated September 2026, 3 weeks ago
Plastic can be environmentally friendly – if it’s made from milk!
Equipment: glass of warm milk, thermometer, funnel, gauze, white vinegar, tablespoon, food coloring, silicone ice molds.
Add four tablespoons of vinegar to a glass of warm milk (about 45 °C / 113 °F). White lumps of milk protein begin to form. Filter the protein out by pouring the liquid through a funnel with gauze. Take the protein and carefully squeeze out any excess moisture. Divide the resulting mass into two equal parts. Add a different food coloring to each half. Fill some silicone ice molds with the colorful mass and leave to dry for two days. You’ve made solid multicolored figurines! You can play with them or even use them to draw on asphalt or on a chalkboard!
Milk protein consists of casein and whey protein. Casein is evenly distributed throughout milk in the form of very, very small particles, which give the liquid its white color. With the application of heat and addition of acid, these particles clump together and combine with the whey protein to form a white mass of very large molecules. When this mass dries, it hardens like plastic. The moisture loss also causes the mass to decrease in size. The process yields a hard but rather fragile material, which you can draw with just like a crayon.
A similar experiment is included in the “Chemistry of materials” set from the MEL Chemistry subscription.
Warning! Only under adult supervision.
Plastic can be environmentally friendly – if it’s made from milk!
Equipment: glass of warm milk, thermometer, funnel, gauze, white vinegar, tablespoon, food coloring, silicone ice molds.
Add four tablespoons of vinegar to a glass of warm milk (about 45 °C / 113 °F). White lumps of milk protein begin to form. Filter the protein out by pouring the liquid through a funnel with gauze. Take the protein and carefully squeeze out any excess moisture. Divide the resulting mass into two equal parts. Add a different food coloring to each half. Fill some silicone ice molds with the colorful mass and leave to dry for two days. You’ve made solid multicolored figurines! You can play with them or even use them to draw on asphalt or on a chalkboard!
Milk protein consists of casein and whey protein. Casein is evenly distributed throughout milk in the form of very, very small particles, which give the liquid its white color. With the application of heat and addition of acid, these particles clump together and combine with the whey protein to form a white mass of very large molecules. When this mass dries, it hardens like plastic. The moisture loss also causes the mass to decrease in size. The process yields a hard but rather fragile material, which you can draw with just like a crayon.
A similar experiment is included in the “Chemistry of materials” set from the MEL Chemistry subscription.
Warning! Only under adult supervision.






![Fake chemical cut
Oh, no! You slipped and cut your hand on a plastic knife! Wait, what…?
Equipment and reagents: iron(III) chloride, potassium thiocyanate, sodium fluoride, water, plastic knife, cotton wool, tweezers.
Prepare solutions of iron(III) chloride, potassium thiocyanate, and sodium fluoride by dissolving the respective reagents in water. Soak a cotton ball in the solution of potassium thiocyanate, then rub the cotton ball on your hand. Dip a plastic knife in the solution of iron(III) chloride and draw it gently across your palm. This creates a bloody “cut” on your hand! Treat it by wiping a cotton swab dipped in the sodium fluoride solution across the “wound.” Your hand is safe and sound!
Naturally, there was never any blood on your hand. What you observed was a chemical reaction that occurs between the solutions of potassium thiocyanate and iron(III) chloride. Thiocyanate ions and ferric ions form complex, blood-red compounds, the most well-known of which being iron(III) thiocyanate:
FeCl3 + 3KSCN=Fe(CNS)3 + 3KCl Adding sodium fluoride destroys the iron(III) thiocyanate complexes, and colorless hexafluoroferrate(III) [FeF6]3- ions form.
Fe(CNS)3 + 6NaF=Na3[FeF6] + 3NaCNS
Safety precautions: do not try it at home! Perform this experiment only under professional supervision. Fake chemical cut](https://i.ytimg.com/vi/pJyrLced5Iw/mqdefault.jpg)



