condensation question

[rocksolid]

If I put something hot in a small plastic or metal lined box and pump the air out of this sealed box will that keep condensation from forming on the inside?

[ewmon]

Essentially, are you asking if gaseous water will move through a vacuum (disperse throughout an evacuated container) from a mass hot enough to vaporize the water it contains? Let's exaggerate the situation: If this mass was the end of a steam pipe (with steam coming out), what do you think the steam would do inside the evacuated container?

[rocksolid]

I put my sons hot lunch in a container and it was soggy when he got to school. I was wondering if taking the air out of this container would keep the food dry and warm.

[ewmon]

I don't think a vacuum within the container itself would make much difference. (Read on.)

 

What became soggy? The plastic/metal container? By "soggy", I think you mean lined with moisture, instead of saturated with moisture (as soggy paper or cardboard would be). On the other hand, if the lunchbox had enough openings to let the water vapor out, there'd be a minimum amount of condensation inside.

 

I'd be more concerned that a hot lunch would lose its heat before it was eaten, and microbes in the food would grow and cause food poisoning (hopefully only a mild case).

 

Meal containers with evacuated liners are probably your sons' safest and most enjoyable way to enjoy a hot lunch from home. I think the original brand of these types of containers are called Thermos, but there are many other brands on the market, some probably made with plastic or metal liners instead of fragile glass.

 

You mentioned wanting to "keep the food dry and warm", but the moisture is coming from the food. For example, you'd be amazed at the amount of water in three slices of French toast. When that moisture has time to escape, the apparently dry French toast actually become drier.

Edited February 29, 2012 by ewmon

[rocksolid]

It was filled with Chicken nuggets and french fries and by time he got to school the food was soggy and he would not eat it. I am trying to think of a way to keep it from getting soggy and still keep it dry and warm. I thought by removing the air in the container then condensation would not form. I am assuming that is what happened.

[ewmon]

I would guess it was the fries that got soggy, perhaps along with the breading on the nuggets. The moisture would have come from the chicken. You could put the "victim" fries (or the "culprit" nuggets) in a sealable sandwich bag, but it seems that the nuggets' breading will suffer either way. You can try putting a paper towel in with the source of the water (here it's the nuggets) to absorb the water. Try wrapping the nuggets with a couple of paper towels, and then put that packet into a sealable bag. Let us know how this works.

Edited February 29, 2012 by ewmon

[rocksolid]

would putting a Desiccants of some type in the container work?

[CaptainPanic]

Fries are crispy because the outside is very dry. But the inside of the fries is still moist.

 

The fact that it becomes soggy (I think) is that the moisture inside the fries is distributed more evenly.

 

So, vacuum will not help at all, because the moisture is already inside the fries. I think your only option is to give a different type of lunch. You should eat your fries when they are still warm, or not at all.

[Fuzzwood]

It was filled with Chicken nuggets and french fries and by time he got to school the food was soggy and he would not eat it. I am trying to think of a way to keep it from getting soggy and still keep it dry and warm. I thought by removing the air in the container then condensation would not form. I am assuming that is what happened.

 

Not to complain about your parenting skills, but what happened to plain old bread instead of unhealthy foods?

[ewmon]

Fries are crispy because the outside is very dry. But the inside of the fries is still moist.

I was thinking that the high heat of frying would drive out most of the moisture in potatoes (¾ of a potato is water).

 

Food tips? I found regular sandwiches were a disaster with my kids, so I made them pita pockets, which can withstand the treatment kids give them. Especially strong when used with a "binder" (aka peanut butter, tuna or chicken salad, etc), ), but pockets also do well in controlling regular loose sandwich fillers (lettuce, cheese, meat, pickles, tomatoes, etc), etc. Between mayo, ketchup and mustard, I choose mustard because it doesn't tend to spoil and has few, if any, calories.

 

Hot meals? I can't see a hot meal remaining hot without the moisture. I recommend those double-walled, evacuated liners. And I wonder how well a hot water packet in the container would work to keep any food (even dry foods) hot for a few hours. Soup at a bustling cafeteria lunch table is probably out of the question, but maybe stews, small baked potatoes, winter squash, pizza slices, calzones, etc. (Now I'm getting hungry)

 

Overall suggestion: Whatever you do, try experimenting and validating: Make these lunches on weekends, and see for yourself how "hot", soggy, "untasty", disgusting, etc they really are by lunchtime (you actually eat them). Heat/cook/pack them in the morning, and set them on the counter. Then try them at lunch. Even do robustness testing. Turn the container upside down, drop it on the floor, and then set it on the counter. (Hey, you're talking to scientists here)

[rocksolid]

My son is Autistic and does not eat many foods. Maybe you should think before you make dumb comments. Sometimes a parent is not a bad parent, sometimes they have circumstance that they have no control over. Not that I need to answer to you or anybody else for that matter but I did want you to think in the future before you judge.

 

Not to complain about your parenting skills, but what happened to plain old bread instead of unhealthy foods?

Edited February 29, 2012 by rocksolid

[ewmon]

My son is Autistic and does not eat many foods.

I sympathize with you. I had a cousin with Down syndrome. My friends have an autistic son, and one day at about age 10, an epiphany occurred, and he went from always needing diapers to never (ever) needing them again. They said it was as though a switch was flipped.

 

I wonder if he's responding to the tactile sensation of the fried crusts of the nuggets and fries more than the actual foods themselves? Have you tried batter-fried vegetables?

[Fuzzwood]

Where do you see me judging? Just wondered something about exotic lunches.

[rocksolid]

You are judging because even though you say " not to complain about your parenting skills " you really are passing judgement becuase you toped off your question with stating that what I give him for lunch is unhealthy which implies my parenting skills are not good. Why did I even waste the time to type that out to you. There goes another 30 seconds of my life I will not get back.

 

Where do you see me judging? Just wondered something about exotic lunches.

 

We have tried everything with him food wise. Some things he likes and other things he does not, mostly he does not. At least he is eating something.

 

I sympathize with you. I had a cousin with Down syndrome. My friends have an autistic son, and one day at about age 10, an epiphany occurred, and he went from always needing diapers to never (ever) needing them again. They said it was as though a switch was flipped.

 

I wonder if he's responding to the tactile sensation of the fried crusts of the nuggets and fries more than the actual foods themselves? Have you tried batter-fried vegetables?

[CaptainPanic]

Please stop the bickering, guys. It's probably not an insult anyway.

I suggest to open a new thread when you want to discuss eating habits. This is not about what is a good lunch, It's about the distribution of moisture in fries.

 

I was thinking that the high heat of frying would drive out most of the moisture in potatoes (¾ of a potato is water).

It does, but only from the outside.

 

If you would fry the potatoes so long that they become completely dry, they would have the texture of crisps (potato chips).

In fries, the inside of the potato is still soft, and still contains moisture.

 

Given enough time, that moisture from the inside will distribute evenly across the whole potato, and make that crunchy outside soft. A vacuum is not gonna change that. In fact, I don't see any solution to the question, other than frying the potatoes until they are completely dry (but that's not the same taste - and I wouldn't want to eat it... ).

[rocksolid]

Is there a moisture absorbing or moisture control product that I can put inside the container?

[ewmon]

Probably paper towels would work best. Those desiccant packets are too dangerous around children.

[rocksolid]

But would the Desiccant packs work?

[JustinW]

After all the posts in this thread no one has seemed to answer the question yet. The clear answer would be yes. If you vacuumed out all of the air the food inside would not get soggy because there would be no air allowing condensation in the first place. It takes air to condensate, does it not? Warm air mixes with cold air and moisture in the air...blah,blah,blah... Get it? It takes air to condensate. If you vacuum out the air what is left to condensate?

 

edit: to note the sarcasm was not meant toward the OP. It's incredible that such a simple question can be walked around so emphatically. Even questioning a persons parenting skills because they feed their kids chicken nuggets? WTF? Come on people.

 

 

Just sayin'.

Edited March 1, 2012 by JustinW

[CaptainPanic]

Nobody here seems to understand the problem. The main problem is not how to remove moisture. It's something different altogether:

 

Problems:

1. Fries contain lots of moisture. It is already inside the fries - just not on the outside, only on the inside.

2. Fries taste different without the moisture.

 

Fried fries are 1/3rd water. Potato contains 2/3rd water before it went into the deep fryer, and 1/3rd when they come out.

Source: (.pdf article, see table on 2nd page)

 

I know that they feel solid enough, but food always contains loads of water. That's because plants are made of a lot of water.

 

You can try to remove all that water, but that means you drastically change your fries. Fries without any water are called crisps. If you want to eat that, why not buy crisps in the shop???

 

After all the posts in this thread no one has seemed to answer the question yet. The clear answer would be yes.

The clear answer is NO.

I disargee with everything you say... Sorry. I'll explain.

 

First of all: I DID answer the question (there is no solution, other than eating the fries when they are still fresh). Somehow it seems to get ignored. Pity. Makes me wonder why I bother answering.

 

If you vacuumed out all of the air the food inside would not get soggy because there would be no air allowing condensation in the first place. It takes air to condensate, does it not? Warm air mixes with cold air and moisture in the air...blah,blah,blah... Get it?

That's true for the weather systems in the atmosphere. This is a lunchbox, not a planet.

 

 

It takes air to condensate. If you vacuum out the air what is left to condensate?

I think the moisture will always redistribute itself in your fries. The only thing that will help is to fry them right before you eat them.

There is a reason you cannot microwave fries. You must heat them from the outside to make them crunchy. Water on the outside evaporates, but the inside remains moist.

 

You don't need air for condensation. You need water. And in a vacuum, water can still evaporate (which means that it doesn't remain a vacuum, but you get extremely low pressure steam).

 

But would the Desiccant packs work?

They can remove ALL moisture yes. But they will not give you good, tasty, fries. You get bone-dry crisps in the shape of fries.

 

Also, you need a good handful of those packs for each and every lunch, to absorb the moisture.

Edited March 2, 2012 by CaptainPanic

[JustinW]

Captain,

That's true for the weather systems in the atmosphere. This is a lunchbox, not a planet.

The principle is still the same.

 

 

You don't need air for condensation. You need water. And in a vacuum, water can still evaporate

 

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

Are you kidding me? You're telling me that a vacuum sealed package can still allow condensation? You're telling me that you can still have condensation without air? Prove it.

 

 

I think the moisture will always redistribute itself in your fries.

Things can still contain moisture without being soggy. I contend that it was a buildup of moisture on the inside of the package due to condensation caused by the difference in temperature between the heat of the fries and the coolness of the air inside the package. The steam off of the fries condensated inside the package to soak the outside of the fries, inturn making them soggy.

 

Condensation is the reverse of vaporisation. To pull water vapor out of the air, you need air in the first place. Once a package is vacuum sealed there is no air for water to be pulled out of.

If there is a different new cool way that water vapor acts please provide me with some linkable proof.

[rocksolid]

Wow, this thread really has taken off. Thanks for all of the replys. I have actually cooked french fries in a Microwave, they now have some silver platform in the box of fries that lets you cook them there. True they are not as good as oven cooked but they are pretty close. If I used a Desiccant pack and taped it to the inside of the lid of where the lunch is do you think that would work? Would it atleast keep the chicken nuggets dry and warm?

[JustinW]

rocksolid,

 

They sell vacuum sealers for cellophane packaging at the grocery store. I'm pretty sure that will fix your problem.

[ewmon]

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

...

Are you kidding me? ... condensation without air? Prove it.

Henri Nestlé proved evaporation without air 150 years ago. Evaporation without air produces freeze-dried foods (fruits, instant coffee, etc), medicinal products (vaccines, plasma, etc), and other consumables.

 

Thomas Newcomen proved condensation without air 300 years ago. In fact, steam heat only works due to condensation without air (ask an HVAC mechanic what happens if air enters the steam system).

 

If I used a Desiccant pack and taped it to the inside of the lid of where the lunch is do you think that would work?

Desiccant packs draw out trace amounts of water vapor, but not the amounts that concern us here. Besides, I would not trust a desiccant pack with any child, and I think cafeteria monitors would also have concerns if they see it.

Edited March 2, 2012 by ewmon

[JustinW]

Henri Nestlé proved evaporation without air 150 years ago. Evaporation without air produces freeze-dried foods (fruits, instant coffee, etc), medicinal products (vaccines, plasma, etc), and other consumables.

This wouldn't work the same way. Vacuum wrapping cellophane isn't like creating a vacuum in a container of water that still has an open portion above the water to allow a low pressure evaporation. Not to mention you're talking about things that deal with a greater amount of moisture. With freeze-dried foods, come on man, have you even looked at the process of freeze drying foods? I doub't it vacuum sealed cellophane for warm chicken nuggets is involved.

As a matter of fact: Freeze-drying (also known as lyophilisation, lyophilization or cryodesiccation) is a dehydration process typically used to preserve a perishable material or make the material more convenient for transport. Freeze-drying works by freezing the material and then reducing the surrounding pressure to allow the frozen water in the material to sublimate directly from the solid phase to the gas phase.

 

 

Thomas Newcomen proved condensation without air 300 years ago. In fact, steam heat only works due to condensation without air (ask an HVAC mechanic what happens if air enters the steam system).

This doesn't apply either. In this scenario, you're heating water to a boiling point to force steam out of a pipe. The process of boiling the water creates it's own gas in the form of water vapor. Which if I'm not mistaken has oxygen in it. Hmmm. We're looking for moist not soggy for our kids chicken nuggets (we can't have them eating soggy nuggets:) ) and I believe a vacuum wrapped cellophane is an easy, inexpensive fix to the problem. Edited March 5, 2012 by JustinW