Microbiologist Investigates After Her Beef Soup Turned Blue in the Fridge

Re:Microbiologist Investigates After Her Beef Soup Turned Bl... by quesera on Friday March 10, 2023 @03:29PM (#35100494)

I remember a grade school science experiment where something about moisture or humidity caused a color change from blue to pink (or vice versa?).

I think the important bit was cobalt chloride. Doesn't sound like an ingredient in hibiscus tea though!

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Re:Microbiologist Investigates After Her Beef Soup Turned Bl... by jgamman on Friday March 10, 2023 @06:52PM (#35103043)

silica dessicant. chemists use it in their dessicators to keep things dry - pink is dry, blue is 'full' (i think, it's been 25 years...). i think it's a low level cobalt doping and as the silica matrix swells with water absorption it changes the UV absorption and the colour changes. or something like that.

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