condensation question

[CaptainPanic]

Captain,

The principle is still the same.

 

 

 

 

Evaporate into what? There is nothing to evaporate into once the package is vacuum sealed.

True.

If you want to suck the fries vacuum (and completely remove all air), in a vacuum sealed bag, the water will not form a vapor phase, as the temperature is below the boiling point, and there is no room to evaporate into.

 

However, I'm sure it will still re-distriute itself in the fries. I would be surprised if this solves anything.

 

Also, since the fries are full of gas (they are porous!), you might collapse the fries themselves into a much thinner and more dense piece of potato.

 

If anyone wants to try to put fries into a vacuum bag, and suck all air out, I would like to see a youtube of that. I think it could be funny (and educational).

 

However, JustinW, I disagree with your explanation. Water at room temperature has a vapor pressure, so given any volume to evaporate into, some water will be in the vapor phase. Air is irrelevant to it.

 

It's the lack of any volume to evaporate into that stops the evaporation... not the lack of air.

 

If you would heat up your fries to 100 degrees, while still in that vacuum bag (sealed), it would blow up like a balloon - with only steam inside. Cool it down again, and it would collapse again, because the water would concense (probably also on the outside of the fries, btw).

[JustinW]

However, I'm sure it will still re-distriute itself in the fries. I would be surprised if this solves anything.

Redistribute how? It's not like the moisture will build up and pool in the bottom, especially in the amount of time the kids leave to when they eat lunch. Without air and at room temperature the fries should retain their moisture. Without evaporation or condensation moisture should not pool inside the package, not to mention a vacuumed package would give no excess room for anything to pool.

 

Also, since the fries are full of gas (they are porous!), you might collapse the fries themselves into a much thinner and more dense piece of potato.

I could see this if the vacuum was strong enough, but a vacuum sealer from the grocery store is only made to pull the air out. Not to provide a strong vacuum.

 

 

If anyone wants to try to put fries into a vacuum bag, and suck all air out, I would like to see a youtube of that. I think it could be funny (and educational).

Check this out:

It shows just how strong a vacuum can actually get. Plus it's cooler than hell.

 

 

However, JustinW, I disagree with your explanation. Water at room temperature has a vapor pressure, so given any volume to evaporate into, some water will be in the vapor phase. Air is irrelevant to it.

I never said it didn't and I agree with this. I was meaning to imply the pressure of the steam off of the boiling water I believe.

It's the lack of any volume to evaporate into that stops the evaporation... not the lack of air.

I could agree with this too now that I think about it. The pressure caused by the steam expanding in the package, etc...Once the package cooled again the vapor would condense to liquid form and poof, soggy fries. (poor kids)

[CaptainPanic]

Redistribute how? It's not like the moisture will build up and pool in the bottom, especially in the amount of time the kids leave to when they eat lunch.

As said before, it is not homogeneous to start with: just after frying, moisture is found only at the center of the fries, not the outside... If you give it time (like a few hours), it will distribute itself also to the outside.

 

And that's exactly why they become weak, and lose the crunchiness.

[JustinW]

As said before, it is not homogeneous to start with: just after frying, moisture is found only at the center of the fries, not the outside... If you give it time (like a few hours), it will distribute itself also to the outside.

How does this redistribution occur? Is there some internal force acting upon the moisture to drive it from the center?

[CaptainPanic]

How does this redistribution occur? Is there some internal force acting upon the moisture to drive it from the center?

Yep. Entropy.

To say it in scientific words: Stuff just wants to mix.

 

Although other phenomena might work too (achieving hte same redistribution), like capillary action.

[JustinW]

Entropy? Huh? How do you consider entropy to be a cause? "Stuff just wants to mix" doesn't even come close to describing entropy.

 

I might could see capillary action if given enough time. But the subject doesn't give enough time for the slight amount of moisture to allow such capillation.

[CaptainPanic]

Entropy? Huh? How do you consider entropy to be a cause? "Stuff just wants to mix" doesn't even come close to describing entropy.

I suggest that you read up on Boltzman's theory of mixing stuff, also known as his formula for entropy.

 

I admit that I used popular words to describe entropy - words so popular that it would probably make Mr. Boltzman angry - but stuff really does want to mix (at a molecular level).

[JustinW]

http://en.wikipedia.org/wiki/Boltzmann%27s_entropy_formula this in no way states that "Stuff just wants to mix". What I got from it is, entropy corrolates with quantity and he came up with a formula that describes this. How does this compare to a buildup of moisture in a french fry? And is it not plausible that any entropy built up in the fry could be transfered through the package in the form of heat. Since there is no excess volume in the package, I would say that it would, rather than react to anything within the fry to cause a buildup of moisture.

[CaptainPanic]

http://en.wikipedia.org/wiki/Boltzmann%27s_entropy_formula this in no way states that "Stuff just wants to mix". What I got from it is, entropy corrolates with quantity and he came up with a formula that describes this. How does this compare to a buildup of moisture in a french fry? And is it not plausible that any entropy built up in the fry could be transfered through the package in the form of heat. Since there is no excess volume in the package, I would say that it would, rather than react to anything within the fry to cause a buildup of moisture.

There is no buildup of moisture, there is a redistribution, as is evident from the fact that these fries actually go soggy.

Edited March 10, 2012 by CaptainPanic

[rocksolid]

Thought I would give an update. I tried a few different methods to try and keep the fries dry and warm. I tried a Desiccant pack of clay and that did not absorb enough water. I also bought a zip lock bag that has a pump where you can pump all of the air out. I put chicken nuggets and fries in a bag and pumped the air out. It did not stay warm ( which I expected ) and it still got a little soggy and the fries did get some what flat. I then put the nuggets and fries into a thermos with no lid and then put the thermos into the zip lock bag and pumped as much air as I could out. It seems that when the food cooled it gave the bag some air back and then condensation formed so that did not work either. I am now looking for a meteral that allows air to escape put keep the warmth in. I don't know if that material exist.

[CaptainPanic]

Thought I would give an update. I tried a few different methods to try and keep the fries dry and warm. I tried a Desiccant pack of clay and that did not absorb enough water. I also bought a zip lock bag that has a pump where you can pump all of the air out. I put chicken nuggets and fries in a bag and pumped the air out. It did not stay warm ( which I expected ) and it still got a little soggy and the fries did get some what flat. I then put the nuggets and fries into a thermos with no lid and then put the thermos into the zip lock bag and pumped as much air as I could out. It seems that when the food cooled it gave the bag some air back and then condensation formed so that did not work either. I am now looking for a meteral that allows air to escape put keep the warmth in. I don't know if that material exist.

As I said many times - the moisture is already inside the fries. And it will redistribute itself as long as it's there. And you cannot remove it, because if you do, the fries will taste horrible.

 

Something that can allow air out, but keep heat in is called a blanket - just your average blanket, like you sleep under, should do the trick.

[rocksolid]

How about just keeping the chicken nuggets warm and not wet then. Maybe I will give up on the french fries.

 

What about Gore Tex. Do you think if I put the food in a metal container and then used a lid made of gore tex that would work?

[CaptainPanic]

How about just keeping the chicken nuggets warm and not wet then.

Chicken meat tastes good also when the outside is a little less crunchy, so the effects of the moisture redistributing are not going to ruin the taste so much.

 

Maybe I will give up on the french fries.

Good idea

 

What about Gore Tex. Do you think if I put the food in a metal container and then used a lid made of gore tex that would work?

Yes. But to keep it warm, insulate the rest of the container too.

[zapatos]

Probably something you've already tried but thought I'd mention it anyway. When looking for alternatives for your son, did you search by the food attributes he already likes? For example, high fat and crunchy. I know there are what are essentially potato chips, but they are shaped like french fries. Didn't know if that might be close enough.

[rocksolid]

Yeah we thought of that Zap but I really don't want him eating potato chips for lunch. I relize Chick nuggets and fries may not be that much better. I will keep working at it and post updates when I have them. Thanks again to everybody who is putting their 2 cents in. I really learned alot.

[Leader Bee]

Probably not the healthiest solution but have you tried plenty of salt?

Edited March 14, 2012 by Leader Bee

[rocksolid]

I'm not sure I understand. Plenty of salt? Most of the time I can't even get him to put the new food into his mouth to try.

[CaptainPanic]

I'm not sure I understand. Plenty of salt? Most of the time I can't even get him to put the new food into his mouth to try.

Leader Bee did not post a very serious comment, although it is completely correct.

 

You can dry foods (meat, fish) by salting it (read more here). It takes a few weeks to do that, and completely changes the texture and taste of the food.

[Leader Bee]

Salt is a wonderful preservative and dessicant. Salt absorbs moisture and should help slow down the soggification of the packed lunch, however any ingested salt will also draw moisture from the bloodstream which can make you thirsty which it isn't great for your digestion and makes your liver work harder.

 

Salt has also been linked to heart disease which is the worlds biggest killer: http://www.sciencedaily.com/releases/2009/11/091124204324.htm

 

Top ten causes of death worldwide: http://www.who.int/mediacentre/factsheets/fs310/en/index.html

 

2011 World health report: http://www.who.int/whosis/whostat/EN_WHS2011_Full.pdf

 

Thing is, chicken nuggets are probably already processed to contain a multitude of preservatives, including salt so extra salt would only be a suggestion to draw the moisture away from the meat rather than redistribution to the breadcrumbs.

 

as for the chips/fries i'd go with Captain on this; probably not much you can do here.

 

 

EDIT: broken links.

Edited March 14, 2012 by Leader Bee

[JustinW]

Leader Bee did not post a very serious comment, although it is completely correct.

 

You can dry foods (meat, fish) by salting it (read more here). It takes a few weeks to do that, and completely changes the texture and taste of the food.

Leader bee did have a good idea, which brought this to mind: Wouldn't uncooked grains of rice work also? It would soak up the moisture without the unwanted taste that salt would give.

[Leader Bee]

It would be safer to have in your lunchbox than one of those artificial dessication packs but same effect in the end, surely?

[JustinW]

Though you also run the risk of the moisture softening the rice. But at least then it could be a chicken and rice meal instead of just plain old chicken.

[rocksolid]

I tried a baby diaper this weekend but it did not absorb anything. I think I might be done. It's just not going to work. Thanks again for all of the helkp and suggestions.