Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

It is known fact, that boiling point of water decreases by decreasing of pressure. So there is a pressure at which water boils at room temperature. Would it be possible to cook e.g. pasta at room temperature in vacuum chamber with low enough pressure?

Or "magic" of cooking pasta is not in boiling and we would be able to cook pasta at 100°C without boiling water (at high pressure)?

share|improve this question
1  
I agree it is not very scientific question, but I doubt, that people on cooking.stackexchange.com have experience with cooking at low pressure. :-) –  Viliam Dec 29 '13 at 14:58
10  
Oh, you'd be surprised. –  Beta Dec 29 '13 at 16:26
4  
Boiling is a cooling process, not a heating process. Pasta needs not boil to cook. –  Optionparty Dec 29 '13 at 17:13
    
Though this does not apply to pasta: For certain foods, the central effect of boiling (or heating) them is destroying certain proteins. If I recall correctly, the same effect could be achieved by excessive cooling in some cases. –  Wrzlprmft Dec 29 '13 at 17:35
    
While I don't have specific proof of this, I believe that pasta will "cook" at room temperature just by sitting in water at normal pressure. It takes a long time, but the water will absorb into the pasta giving it a "cooked" texture. Heat just accelerates the process. –  tylerl Dec 30 '13 at 4:55
add comment

7 Answers 7

up vote 45 down vote accepted

No. Boiling doesn't mean that the water will cook anything. If you have boiling water at 30°C you could touch it (if we forget that it's at really low pressure) and nothing would happen. Boiling is not what cooks, but temperature.

In fact, if you want to purify water at high altitudes, you need to boil water more time because it will be at lower temperature.

share|improve this answer
24  
That is also why pressure cooking is used. If you cook something at higher pressure, the water will boil at higher temperature. You then cook at higher temperature and the cooking process is faster. –  Ondřej Černotík Dec 29 '13 at 13:03
4  
It should be added that pasta is also dried and needs to absorb water in order to soften. So you really do need boiling water. –  JSBձոգչ Dec 29 '13 at 17:17
    
So the action of boiling can kill bacteria at low temperature, just by increasing the boiling time?? Do we know how much low-temperature boiling time can be withstood by various species of bacteria? –  hippietrail Dec 29 '13 at 18:11
2  
@hippietrail See this question outdoors.stackexchange.com/q/1117 –  jinawee Dec 29 '13 at 18:21
1  
@hippietrail In sous vide cooking the cooking is done in a low temperature water bath. In time needed to pasteurize depends on the temperature. You can see recommended tables here: douglasbaldwin.com/… Note that different bacteria require different times. –  soegaard Dec 29 '13 at 21:24
show 2 more comments

Well, I can share with you one experience from my high school. I wanted to boil coffee in my caffetier without a cooker. We had the vacuum pump in the physics room so there was the way to "boil" the water without getting it in 100°C. I did it... and coffee tasted horrible.

Never try it again.

share|improve this answer
2  
That is nice geeky idea for coffe machine. Coffe machine with one more setting, temperature of boiling (controlled by increasing/decreasing pressure inside machine). As you stated, coffe proably wouldn't taste good, but you would have option to make coffe e.g. as it would taste in space. :-D –  Viliam Dec 29 '13 at 19:31
    
In space it would taste HORRIBLE :P –  Cheshire Cat May 21 at 18:16
add comment

Pasta does not really need to be cooked. Instead, it needs to become hidrated. Pasta is just like a dry fruit. If you let it in water for a day or so, it will look at least like it has been cooked.

share|improve this answer
    
This is a very interesting half-answer. Has anyone tried it, to see if the result tastes cooked? –  Beta Dec 29 '13 at 15:44
13  
Ehm... I can confirm that leaving the pasta in the cold water does almost the same job as cooking it in the hot water. One time someone told me that she had problems with the pasta she prepared and asked me to taste it and find out what went wrong. I couldn't answer as the taste was of normally cooked pasta. Afterwards, she said she actually did not heat the water –  Ralph Dec 29 '13 at 17:42
2  
@Ralph for how much time, just out of curiosity? –  Juanlu001 Dec 29 '13 at 19:20
add comment

If you hydrate pasta by keeping it in cold water, it won't be 'cooked' from a technical standpoint. Cooking requires heat (or the chemical equivalent, as in ceviche). It will taste like wet, raw flour.

share|improve this answer
    
Does pasta actually cook? Is 5-8 minutes in boiling water enough to do anything chemical to the wheat other than hydrate it? –  Martin Beckett Dec 29 '13 at 19:38
    
Yes, it does cook. In fact, when cooking pasta it is important to have enough boiling water (4L per 500mg) to keep the temperature as high as possible after the pasta is put in. Salt also helps to increase the boiling point. Otherwise the pasta will be sticky and mushy. –  dansalmo Dec 29 '13 at 20:07
3  
@dansalmo This is a common "bad science" error. While salt (or any dissolved chemical) will increase the boiling point of water, it will not change the temperature by a significant amount until it's so dang salty you'd never want to eat the results. –  Carl Witthoft Dec 30 '13 at 20:06
    
I disagree. It will be cooked as it is already cooked (if dried). Boiling dried pasta is technically "re-cooking" it. –  Pete Oakey Jan 7 at 23:25
add comment

Ahem, I come to you from Seasoned Advice (cooking). As Beta suggested, questions like this one would not be uncommon there. The agitation of boiling water has nothing to do with cooking pasta except in that it helps keep the pasta from sticking.

Whether it makes good pasta to hydrate it without heat (or at least a lot of heat) is a source of some debate, but the pasta will be become hydrated (eventually) in even room temperature water, with or without the vacuum.

Certainly the pasta would cook just fine, with no discernible difference in quality, if cooked (hydrated) in non-boiling 100C water (under pressure).

share|improve this answer
add comment

Note that many of the other answers are assuming you are preparing dried pasta, which is of course by far the most common way of preparing pasta. Dried pasta is actually cooked (at temperatures between 60 and 70 degrees C) while it dries; fresh pasta (i.e. flour mixed with eggs and/or olive oil) does therefore need to be cooked in order for the gluten to polymerize correctly (see http://www.biw.kuleuven.be/m2s/clmt/lmcb/publications/docs/cbruneel for some more detail on the chemical processes that occur). It does not, however, need to boil. You should be able to cook it perfectly adequately at about 60 degrees, similarly to the way pasta is dried commercially.

share|improve this answer
add comment

Starches in the durum wheat flour will only activate at boiling temperature. Hydration is irrespective and can be achieved under vacuum.

share|improve this answer
    
you can provide in greater details here also –  qwartz May 28 at 5:57
    
Since water can boil at room temperature, this seems wrong. –  jinawee May 28 at 8:10
    
@jinawee Indeed; see the source I posted above which suggests that hot air heating at 60C is adequate for cooking pasta. –  Jules May 28 at 17:38
add comment

protected by Qmechanic May 28 at 4:55

Thank you for your interest in this question. Because it has attracted low-quality answers, posting an answer now requires 10 reputation on this site.

Would you like to answer one of these unanswered questions instead?

Not the answer you're looking for? Browse other questions tagged or ask your own question.