Why did my yoghurt burst?

[McKenster]

Ok i flew over this morning from LHR to ZUR had a .5 litre tupperware container 75% full of greek yoghurt had one of those lids with 4 clips one each side.
I squeezed the container as i sealed the lid to keep air almost vacume state.
I put it in my suit case, but when i arrived i found hmm quite a bit had leaked from the corner. On inspection the container seems ok?
This was on an A320 so im guessing pressurised hold? Can anyone explain why it might of expanded out of the container?

Thanks!

[Airclues]

Why would you put greek yoghurt in your suitcase? They sell greek yogurt in Zurich.

[RevMan2]

First world problems.....

Cabin pressure is around 2000m and at this level, the air in your container of yoghurt would of ...er...have expanded by about 25%.

[strake]

Ah yes. The problem is it's Greek yoghurt.

If it was British yoghurt, it would have been suitably restrained.

It's a culture thing...

[PAXboy]

Lucky it was only a short haul. If the Yog had a live culture, who knows how much it would have grown by the time you reached Sydney ...

Welcome aboard the fabulous cabin of PPRuNe, McKenster. :)
The air pressue in the whole aircraft drops to be the equivalent of about 6,000 ft above sea-level so the pressure in the tub is now much higher than outside. As in all other areas of the planet, nature tries to equalise the pressure.

[DaveReidUK]

They don't make Tupperware like they used to.

[PAXboy]

I am reminded of the occaision that I packed a roll-on deodorant at sea level and opened it in JNB (= 5,500 asl).

The item was nearly empty and so a fair amount of space inside it with air pressure at sea level. When I unscrewed the top - the roller ball shot out of the base like a ping pong ball, driping a trail of white gloop as it went - all over my suitcase. And - Yes - it did look exactly like what you are thinking ... :uhoh:

The stain is still there some five years later.

[wiggy]

The item was nearly empty and so a fair amount of space inside it with air pressure at sea level. When I unscrewed the top - the roller ball shot out of the base like a ping pong ball

Ahh haa, it's not just me then..fortunately mine was in hand baggage in it's mandatory plastic bag but even so :uhoh:


For the OP

a .5 litre tupperware container 75% full .......

Just like the deodorant container the problem is the air (which is compressible) , not the fluid (which isn't). You see the opposite effect if you seal a water bottle at cruise altitude and then look at it after landiing - a full'ish bottle will retain it's shape, a nearly empty bottle will be crushed and may quite probably have self destructed ( and ruined the contents of your briefcase :\ ). Always minimise the amount of air you "pack" an airtight container....

[TWT]

I tried explaining the pressure thing to some girls who found their shampoo had oozed everywhere in their suitcases.They were blaming rough baggage handling in a minibus and abusing a tour guide.

Waste of time :ugh:

[TightSlot]

Ah yes. The problem is it's Greek yoghurt.

If it was British yoghurt, it would have been suitably restrained.

It's a culture thing...

Excellent, really Excellent! Quite cheered me up over the morning espresso. Now, off to LAX with a smile on my face

[strake]

;) Bon voyage...

[mad_jock]

if you want to transport it again you need to vacuum pack and seal it into a food vacuum bag then heat seal it then put it in the box and leave the lid slightly off.

This was discovered by myself while transporting cow poo samples. The beefing up of the box can work but it then becomes brut force and weight over science. You just need to get rid of the gas so there is no expansion.

You can pick the bags and heat sealer up off the place called a river for 20 quid. And actually they are pretty good for using in the kitchen anyway soup is good as you can just chuck the bag in the microwave soften it up then put it in a bowl to complete the heating.

[McKenster]

Thanks pruners for the fascinating detail and musing quips ;)

Lesson learnt for sure! I mean i was aware of expansion but not by that much. Also schoolboy error leaving the container on it's side in my case.

Often wondered why i see crumpled water bottles leaving my weekly flight, theres me thinking the passengers are being thoughtful about their waste ;)

[Allan Lupton]

Time was when Lufthansa served apple juice in small (100cc?) cup-shaped containers with a tabbed foil lid. They were more or less impossible to open at altitude without the contents going everywhere, but I suppose it educated the pax in the process.

[ExXB]

Ah, KLM had those containers for their OJ. I discover that they could be opened by using a thumb nail to break the seal on the opposite side from the tab, just a very small hole. Once the pressure was released it was easy to open without making a mess.

[TWT]

I always look to see if the foil lid is bulging outward indicating a higher pressure inside the container than ambient.If so,I peel back the lid very very slowly.

[Basil]

As a teenager, I learnt not to pack mucky things with clothes when I opened an overstuffed motorcycle pannier :(

[GingerC]

Same problem with the small plastic pots (jiggers?) of milk, or even worse the plastic tubes of milk, which are supplied with tea and coffee onboard. Never a flight goes by without someone in my row splashing themselves with milk. I've learned my lesson and take tea or coffee black on planes now.

[ruddman]

Why did my yogurt burst?


That's what the kids are calling it nowadays? :}

[RevMan2]

I always look to see if the foil lid is bulging outward indicating a higher pressure inside the container than ambient.If so,I peel back the lid very very slowly.
Perforate the lid with a sharp object, then open
(I was going to say "Prick with a fork", but there's this...Don?t ask me??(about annoying the copywriter) | You Must Be From Away (http://bit.ly/1drWofK))

[Ancient Observer]

strake

quite brilliant. Like tightslot says, brought a smile to my face.

[Catwalk Dweller]

strake

"It's a culture thing... "

Fantastic!

[tomahawk_pa38]

Never noticed it before but when I flew to Tenerife this year, I took out a packet of crisps (Walkers of course) from my hand baggage and it was blown up lke a balloon. I reckon another couple of thousand feet up it would have gone "bang" ! That would have been fun. Decided not to open it to see what happened next but on landing - it returned to normal size as you might expect. Must be good seals on Walkers crisp packets.

[mad_jock]

We have an unpressurised hold. You can be 100% certain that they do pop. Don't know the altitude that it happens but its below 18000ft. They put 4 boxes in that hold that's how I know.

[Piltdown Man]

A typical hold altitude for pressured aircraft is just over 8,000'. Newer aircraft like the 787 will lower that to about 6,000'. Sealed products like crisps will appear to inflate but yoghurt, even in sealed tubs, if upside down will be pushed out of the container by the residual air inside. Air pressure at 8,000' is approx. 11 psi. The air was captured at 14 psi, therefore the pressure on the yogurt was 3 psi. Solution? Don't carry yoghurt or buy a better container.

[Munnyspinner]

I can't actually believe this has already covered two pages. Well done. Not sure which is more baffling. The fact it leaked to to reduced cabin pressure or the fact it was being carried at all.

[McKenster]

Why are you baffled about me carrying greek yoghurt? :confused:

I had mentioned up until now it wasn't freely available here in Zurich so i bring my own over. You got a problem with that?

[tdracer]

I go skiing in Breckenridge, Colorado on a regular basis. The community of Breckenridge is right at 10,000 ft. (the place we usually stay is a couple hundred feet higher).

It's mildly entertaining to walk down the aisles in the local grocery store and see all the bulging packaging of the items that were packaged at sea level :E.

[Evanelpus]

Why did my yoghurt burst?


......and your other half is buying this story? Incredible:ugh:

I always used to say it was toothpaste, worked for a while.:ok:

[RevMan2]

You got a problem with that?

You haven't quite got the Mafia accent right...

It's "You godda a problem wit dat?"

[meadowrun]

I would dearly love to bring British and Welsh bacon back here but they won't let me even for personal consumption only. And it doesn't burst. Have to content myself with a couple of parting bacon sarnies for in-flight. Usually beats the offered meal.

[Fran Tick]

Is British joghurt really joghurt though ?

I'd hazard the Greek stuff is much closer to its roots.

I find British joghurt lasts way beyond its sell by date, by a week or so.
That's not cultured.

[PAXboy]

So true. The stronger the culture - the more volatile it tends to be ... ;)

[Fran Tick]

Bulging packaging ? It's not just that the salads are reaching their sell by date then, tdracer in Breckenridge ?