Hues of Chemistry
The Making¶
- Cutting the cabbage
Red cabbage (Brassica oleracea) is an edible vegetable that contains antocyanin pigment. This particular pigment is fugitive (not color-fast), which means, that the fabrics dyed with it will not maintain color permanently. It will eventually wash off or fade in the sunlight. The pigment is also highly ph-sensitive and fabrics may change color when exposed to acidic or alkaline environment or substances. It may be used to produce DIY litmus paper strips to detect the ph level of substances.
Tools: metal pot, stirring spoon, digital weight, mesh strainer, latex gloves, knife, cutting board, beaker Ingredients: Red Cabbage, water, kitchen salt,
- Chop the cabbage into medium pieces
- Place in a metal pot
- Add kitchen salt as an intensifier (1-3 tablespoons/500g)
- Add water, just enough to cover the cabbage
- Simmer for 2 hours (do not boil, it may damage the pigment)
- Strain the dye, pour the liquid in a beaker
- The leftover cabbages can be eaten as salad or some curry, or put them in dehydrator, crush them and use it as raw ingredient for biomaterials!!
- Pure colour of red cabbage
50 Shades of Cabbage¶
- Dye + Vinegar = Shades of pink (Intensity of the colour depends on the quantity of vinegar used).
You can modify the Red Cabbage dye with various substances. As cabbage is highly ph-sensitive, the best modification results are obtained by modification of ph levels.
Here I have used
- sodium alteration, Which turns the dye to blue in colour because it is very basic in nature (Here I have used sodium bicarbonate).
- vinegar alteration, Which turns the dye to red/pinkish in colour because it is very acidic in nature (Here I have used kitchen vinegar).
- Further, I tried adding some alum in one of the pot, and it turned green.
- Also tried mixing alum and vinegar (I would not recommend to do so, as at first it makes some bubbles and gives very pungent smell) but it gave a very beautiful turqouise blue colour.
Even after the dye has been incorporated in the biomaterial, it changes colour throughout.. The piece with alum and vinegar changed it's colour from turqouise blue> Navy blue> Green> Yellowish green.
- The reason for choosing Red cabbage was that the colour is very fugitive i.e. the colour will fade away if put it under the sun. Which could act as a good depiction for the phenomena of coral bleaching, also giving a sense of taking more care of your garments/belongings so that it can last longer.
- 50 shades of cabbage
Do's and Dont's¶
- Here I left the red cabbage in dehydrator, and it stopped working, thus the mold.
- Always add Tea Tree oil when working with red cabbage as it gets molded very easily.
- Also, the dye has a very strong smell so better to add tea tree oil.
- Always store the dye in glass container and in fridge to make it stay for longer.
- For drying the cabbage leftovers in dehydrator, Always put settings on 45 degree celcius for 24 hours, Or you can increase the temprature to make it dry faster.
- Here I accidently left the dye with vinegar in open for 2 days, Thus the mold.