Can alot of gas build up in a gal plast. milk cont. so that the cap when sat on top would plop up and down?

Question

I took a plastic gallon milk container out of the refrig to put some milk in my coffee. This had less than a half inch of milk left in it. It was not exp milk as I checked the exp date (Aug. 4, 2006). The cap was the kind that you push down to secure not the screw kind. Anyway, I poured some milk in my coffee, sat the cont. on the counter and then sat the cap on top but did not push down (as I usually don't add the right amount on the first try). As I am adding sugar to my coffe and tasting, the cap begins to rise on one side and then plop down. It rose and ploped over and over again for approx. a minute, at which time I thought, "what the heck?", (and it was still going but the time between plops had slowed), I decided to stop it and pushed down on the cap to secure it. To try and describe it, have you ever seen one of those old steam pipes with the top hinged on one side so that when steam is pushing it up it won't blow completely off? This was not one pop but a rise/plop over &over.

Answer 1

The air in the milk carton, cooled below room temperature in the fridge, began to heat. Since the cap was not securely in place, the expanding air lifted it up. Once the pressure was released, the cap fell. Repeat the cycle.

I've seen this too (and had to explain it to one of my kids).

Answer 2

You took the container out of a cold refrigerator and set it on a warm counter and wonder why that happened? Both liquids and gases expand as they warm up.

Answer 3

This does not sound right... how can this happen when u just took the container out of the fridge?

Answer 4

yes

Answer 5

If I were you I would stop adding acid and shrooms to my coffee. :)