Don’t drink pink milk

by Daniel Parnitzke

What if the minimum expiration date would actually display the process of food turning bad. It could help the consumer to keep track of the different stages of food expiration and oxidation.

Don’t drink pink milk shows the increasing acidity of milk while turning bad. An indicator increases the milk’s red color to visualize the aging process. Due to the gradually change of color the consumer can see the aging stage of the milk.

The bottle of milk has two chambers which both contain the same milk and which are facing the same surrounding conditions. The bottom chamber contains the indicator.

Bottle of milk with indicator
The indicator at the bottom of the bottle of milk shows wheter or not the milk is sour or not.


radishes and radishskin


Skins from radishes are used to make a PH indicating fluid together with ethanol.


radish skin indicator
Radish skin indicator made out of radish skins and ethanol.


souring milk with radishskin indicator
A glass of souring milk indicating the PH value by change of color.


souring milk experiment
Measuring the PH value of milk getting sour every few hours over 2,5 days.




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