Stupid question but I've never seen this before

What does it mean when a glass jar which contains a food item  has a note on the cap which says "do not reseal cap"? It's one of those caps that pops up if there's bacteria in the food. What do I do with the jar once it's been opened?

(It's Sainsbury's chicken spread and crab spread, by the way. I've already opened the jars to taste the spreads, closed them and put them in the fridge.)

what that means is....dont reseal and put back on the shelf..u'll be ok with it in the frige...use as u would anything else

What does it mean when a glass jar which contains a food item  has a note on the cap which says "do not reseal cap"? It's one of those caps that pops up if there's bacteria in the food.

It doesnt pop up to say that there is bacteria in the food... it just pops up if the jar has been opened and there is air inside.

Wow, this is an old thread.

But I meant that if the bottle popped up before the jar was opened, it means that there were anaerobic bacteria present before the jar was opened. The reason the bottle would have popped up was because the bacteria were creating gas inside the bottle.

Oh right, gotya! 

(i was rummaging through old threads today, and this one caught my eye...)