The sauce was to expire in Nov 2013. I kept it in the fridge all the time. The thing that grew on it was white in color (just like cotton). There was a greenish center. The overall "ball" was about 1 cm in diameter, and they were all over in the bottle.

I don't have a picture of it, because I had to throw it out. I don't know what it was, or how it started growing.

What was it? Why was it there?

  • 1
    FUNGUS Commented Feb 2, 2013 at 23:19
  • 4
    Note that the expiration date applies only to an unopened jar. Once open, you can't count on more than a few days before it starts getting fuzzy.
    – Marti
    Commented Feb 3, 2013 at 16:33

2 Answers 2


It's mould. You've probably seen it growing on bread. Refrigeration slows it down, but eventually it'll grow.

You didn't say when you bought it and opened it. Perhaps your fridge is not set cold enough?

  • In terms of timeline, I bought it on day 0, opened on day 3, and refrigerated it ASAP. Then the second time, I opened it on day 6-ish, and found some of the mold. I'm just confused how can mold grow on a new food product in the fridge.
    – None
    Commented Feb 2, 2013 at 23:26
  • So what is the temperature of your fridge? Are you sure the door is still sealed correctly and it's in working order? I ask this as a person who once had a fridge with a slightly wonky door and this made everything spoil really quickly.
    – Megasaur
    Commented Feb 2, 2013 at 23:37
  • I don't know about the temperature. But it is pretty cool. The door is fine though.
    – None
    Commented Feb 2, 2013 at 23:47
  • @KaranGoel Your fridge should be in the 2-4C range, not just cool, but close to freezing.
    – Cascabel
    Commented Feb 3, 2013 at 0:37
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    To answer the question how anything could have grown in there -- did you dip anything into the container that might've been contaminated? A spoon that's also touched other stuff can be enough to add mold or other contaminents.
    – Joe
    Commented Feb 3, 2013 at 19:47

Like @sarino and @megasaur mentioned already, it is mold and you did the right thing by throwing it away. This link explains pretty well why mold grows on the food: http://wanttoknowit.com/why-does-mold-grow-on-food/

Also, the reason that food stays good in these unopened bottles in normal temperatures is that the food is vacuum sealed, so it doesn't come into contact with air or outside moisture. Once its opened, it is highly recommended to go into the fridge straight away, like you did.

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