Sometimes people forget that their milk expired yesterday and begin to consume the hearty substance for breakfast and dinner for the next day before realizing it has gone bad, imagine that a new sticker on the label changes from blue to red after so many days. It only changes color on the expiration date. To warn people this sticker will be placed around the lid of all perishable items.
-- Slaith, Mar 02 2006

Simla Smart_20Food_20Containers
....but different. [DrCurry, Mar 02 2006]

A review from several years ago http://faculty.che....rtLabel-rev3B&W.pdf
There are some commercially available systems now. Supermarkets won't use them. [ConsulFlaminicus, Mar 02 2006]

Some of the many patented systems in the US alone http://patft.uspto....RM2=&FIELD2=&d=ptxt
[ConsulFlaminicus, Mar 02 2006]

I remember this idea Day_20Dots
color changing day dots are available through restaurant suppliers. [jaksplat, Mar 03 2006]

This should be on every perishable food item, I have gotten very ill due to food that I had bought at a WALMART due to it being expired, it was a papa johns pizza! I didnt think to check it for being expired since I had just bought it! it turns out its was actually one month expired, I had no idea how it had come to be on their isles. I dont know any people who check the expiration date on everything as soon as they buy it, so a color changing label system would help people not buy expired food. No I'm not some bum who eats expired food lol, I just never thought something that I bought in a walmart would be a month over due. Now I check things before I buy them lol
-- Slaith, Mar 02 2006


I thought that this had been posted at least twice before, including a version which was temperature driven and so provided a more accurate indication of the bacteria levels in the food. However, I can't find the ideas, so [+].
-- wagster, Mar 02 2006


I believe that this is in the baking dep't of some NPD lab, as we speak.
-- skinflaps, Mar 02 2006


Ideally, I guess, the labels would contain cultures of the bacteria that cause food spoilage, along with an indicator that measures some unique component of their excreta.
-- coprocephalous, Mar 02 2006



random, halfbakery