# What's so magical about the boiling point of water? **URL:** \ **Category:** Factual Questions\ **Created:** [November 25, 2008, 10:05pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488 "2008-11-25T22:05:09Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![hotflungwok](https://avatars.discourse-cdn.com/v4/letter/h/edb3f5/32.png) [@hotflungwok](https://boards.straightdope.com/u/hotflungwok)\ **Post date:** [November 25, 2008, 10:05pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/1 "2008-11-25T22:05:09Z")
I’ve often wondered this when cooking. What does bringing the water to the boiling point do? I see it for soup, and cooking noodles, and anything where the idea is dissolving something in water. I was making a dessert one time and I had to bring milk to a boil, and then remove from heat and do other stuff. When purifying water, you’re supposed to boil it. I’ve always heard that you don’t need to boil it for X amount of time, just that it reaches the boiling point. So what’s the deal? What’s so magical about the boiling point? ---
**Author:** ![MOIDALIZE](https://avatars.discourse-cdn.com/v4/letter/m/e274bd/32.png) [@MOIDALIZE](https://boards.straightdope.com/u/MOIDALIZE)\ **Post date:** [November 25, 2008, 10:10pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/2 "2008-11-25T22:10:32Z")
Well, as I understand it, once a liquid reaches its boiling point, it begins to boil. ---
**Author:** ![TimeWinder](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@TimeWinder](https://boards.straightdope.com/u/TimeWinder)\ **Post date:** [November 25, 2008, 10:15pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/3 "2008-11-25T22:15:50Z")
Well, barring special conditions, it’s as hot as water will get–so there’s the “easy to recognize maximum” benefit: for many things 90 degrees © might work just as well, but that requires a thermometer – 100 C is so easy to detect by eye that a first grader can do it. Second, it’s a state transition point: steam carries much more heat energy, so if you want steam, boiling is pretty much a requirement. For covered things, there’s a pressure relationship here, too – the more steam, the more pressure (assuming a reasonably tight lid). Bringing water to a boil is also likely to affect the water IN things being cooked, for the same reason. Last, there’s agitation. Water can get to about 95 degrees and remain basically still; if you want to physically mix/agitate things, boiling can help. Mostly, though, I think it’s just the first one: it’s hotter than water normally gets in nature, so most micro organisms don’t evolve to survive it – and it’s easily recognizable that you’ve gotten there. By the way, sterilization often _does_ require more than instantaneous boiling – you’ll often see instructions to boil something for at least X minutes to sterilize it. ---
**Author:** ![BubbaDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bubbadog/32/333_2.png) [@BubbaDog](https://boards.straightdope.com/u/BubbaDog)\ **Post date:** [November 25, 2008, 10:18pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/4 "2008-11-25T22:18:14Z")
I guess they could say bring the water to 194 degrees and then add the noodles but its a whole lot easier just to notice that the water is boiling than to monitor the temperature any other way. And water that reaches the boiling point has given you a definite sign that it has reached a temperature that kills harmful bacteria. The thermometer just might lie. ---
**Author:** ![Roadfood](https://avatars.discourse-cdn.com/v4/letter/r/9fc348/32.png) [@Roadfood](https://boards.straightdope.com/u/Roadfood)\ **Post date:** [November 25, 2008, 10:20pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/5 "2008-11-25T22:20:24Z")
Well, two things: When it comes to dissolving stuff, the warmer the liquid, the more easily things dissolve in it. Since the boiling point is the warmest that water can get, there you go. When it comes to purifying, I believe the basic idea is that pretty much all Earthly life forms are able to live in a relatively narrow band of temperature that sorta-kinda coincides with the temperature band in which water is liquid. There’s nothing magical there, it’s just that Earth developed to have that temperature, and thus allowed liquid water to exist, and thus life evolved somewhat hand-in-hand with that temperature, not to mention with water itself. So your typical evil germs and bacteria and such tend to die in boiling water. ---
**Author:** ![Santo\_Rugger](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@Santo\_Rugger](https://boards.straightdope.com/u/Santo_Rugger)\ **Post date:** [November 25, 2008, 10:29pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/6 "2008-11-25T22:29:59Z")
> [@TimeWinder](#): > > Well, barring special conditions, it’s as hot as water will get… Special conditions only means under a bit of pressure. That’s why pressure cookers work; they allow the water to get hotter than 100C or 212F. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [November 25, 2008, 10:31pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/7 "2008-11-25T22:31:37Z")
> [@Roadfood](#): > > Well, two things: When it comes to dissolving stuff, the warmer the liquid, the more easily things dissolve in it. While this is _generally_ true, the real world conspires against the universal truth of statements such as this. Sodium sulphate becomes _less_ soluble in water as the temperature increases, as do most gases: [googleage](http://www.elmhurst.edu/~chm/vchembook/174temppres.html) with graphs. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [November 25, 2008, 11:53pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/8 "2008-11-25T23:53:13Z")
> [@Squink](#): > > While this is _generally_ true, the real world conspires against the universal truth of statements such as this. > Sodium sulphate becomes _less_ soluble in water as the temperature increases, as do most gases: [googleage](http://www.elmhurst.edu/~chm/vchembook/174temppres.html) with graphs. In cooking, it is generally assumed that everything dissolves better in hot water. This is true for sugar, as most cooks know; making syrup by putting sugar in boiling water then cooling it gives better results for lemonade than just pouring the sugar into cold water. However, it is not true for table salt. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [November 25, 2008, 11:58pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/9 "2008-11-25T23:58:41Z")
> [@CookingWithGas](#): > > In cooking, it is generally assumed that everything dissolves better in hot water. This is true for sugar, as most cooks know; making syrup by putting sugar in boiling water then cooling it gives better results for lemonade than just pouring the sugar into cold water. However, it is not true for table salt. Correct. Table salt makes lousy lemonade. ---
**Author:** ![Washoe](https://avatars.discourse-cdn.com/v4/letter/w/ecae2f/32.png) [@Washoe](https://boards.straightdope.com/u/Washoe)\ **Post date:** [November 26, 2008, 12:01am UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/10 "2008-11-26T00:01:14Z")
What about enzymes? I remember reading somewhere once that there are enzymes which are deactivated at _exactly_ the boiling point of water. Is this actually true, and if so, why is it true? ---
**Author:** ![Cider\_Depot](https://avatars.discourse-cdn.com/v4/letter/c/e274bd/32.png) [@Cider\_Depot](https://boards.straightdope.com/u/Cider_Depot)\ **Post date:** [November 26, 2008, 12:06am UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/11 "2008-11-26T00:06:27Z")
The usefullness of the cooking term “boiling” is somewhat reduced at higher altitudes, where water boils at a lower temperatures. 70-80 degrees C is simply not hot enough for many applications. ---
**Author:** ![BellRungBookShut-CandleSnuffed](https://avatars.discourse-cdn.com/v4/letter/b/bcef8e/32.png) [@BellRungBookShut-CandleSnuffed](https://boards.straightdope.com/u/BellRungBookShut-CandleSnuffed)\ **Post date:** [November 26, 2008, 12:16am UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/12 "2008-11-26T00:16:33Z")
> [@CookingWithGas](#): > > In cooking, it is generally assumed that everything dissolves better in hot water. This is true for sugar, as most cooks know; making syrup by putting sugar in boiling water then cooling it gives better results for lemonade than just pouring the sugar into cold water. However, it is not true for table salt. Wait, what? If you’re saying that table salt isn’t more soluable in water at a higher temp of water, I’m pretty sure that’s wrong. Unless table salt happens to have different chemical properties than the salt I used when I did this experiment in 7th grade. You can definitely supersaturate water with salt by raising the water’s temp first. It crystalizes when the water cools. ---
**Author:** ![Fish](https://avatars.discourse-cdn.com/v4/letter/f/bc8723/32.png) [@Fish](https://boards.straightdope.com/u/Fish)\ **Post date:** [November 26, 2008, 12:35am UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/13 "2008-11-26T00:35:20Z")
I’ll echo what’s been said before: although garden-variety hot water can kill germs, boiling is certain to do the trick and visible to the unaided eye. You _could_ cook food with merely 175° water, but you’d need a thermometer to be sure it was safely out of the bacterial “danger zone.” ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [November 26, 2008, 12:45am UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/14 "2008-11-26T00:45:58Z")
> [@Cider\_Depot](#): > > The usefullness of the cooking term “boiling” is somewhat reduced at higher altitudes, where water boils at a lower temperatures. 70-80 degrees C is simply not hot enough for many applications. Where are you cooking? At 3,000 meters the boiling point is 89 deg C. You’ve got to go to 6,000 meters to get the temperature down to 81 deg C, and at 8000 meters it’s still 76 deg C. ---
**Author:** ![1010011010](https://avatars.discourse-cdn.com/v4/letter/1/ea666f/32.png) [@1010011010](https://boards.straightdope.com/u/1010011010)\ **Post date:** [November 26, 2008, 1:14am UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/15 "2008-11-26T01:14:12Z")
> [@Washoe](#): > > What about enzymes? I remember reading somewhere once that there are enzymes which are deactivated at _exactly_ the boiling point of water. Is this actually true, and if so, why is it true? WAG 1: If an enzyme incorporates liquid water into its structure, that liquid turning into a gas could interfere with things a bit. WAG 2: Proteins denature at a variety of temperatures, some of them would have _exactly_ 100C by chance. Test: Heat water at high pressure above 100C. If they still work, it’s boiling, not temperature. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [November 26, 2008, 3:24pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/16 "2008-11-26T15:24:28Z")
> [@MOIDALIZE](#): > > Well, as I understand it, once a liquid reaches its boiling point, it begins to boil. [Moderating] **MOIDALIZE,** we ask that posters refrain from jokes in GQ until the OP has received an answer. This isn’t even a particularly clever joke. Please refrain from this kind of remark in the future. Colibri General Questions Moderator ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [November 26, 2008, 3:40pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/17 "2008-11-26T15:40:23Z")
> [@CookingWithGas](#): > > In cooking, it is generally assumed that everything dissolves better in hot water. This is true for sugar, as most cooks know; making syrup by putting sugar in boiling water then cooling it gives better results for lemonade than just pouring the sugar into cold water. However, it is not true for table salt. > [@BellRungBookShut-CandleSnuffed](#): > > Wait, what? If you’re saying that table salt isn’t more soluable in water at a higher temp of water, I’m pretty sure that’s wrong. Unless table salt happens to have different chemical properties than the salt I used when I did this experiment in 7th grade. You can definitely supersaturate water with salt by raising the water’s temp first. It crystalizes when the water cools. Seconded. Your statement regarding table salt is factually incorrect, **CookingWithGas**. The solubility of sodium chloride in an aqueous solution unquestionably increases with increasing temperature. The counterintuitive solubility rule is that the solubility of **gases** in water decreases with increasing temperature. ---
**Author:** ![Captain\_Carrot](https://avatars.discourse-cdn.com/v4/letter/c/f0a364/32.png) [@Captain\_Carrot](https://boards.straightdope.com/u/Captain_Carrot)\ **Post date:** [November 26, 2008, 3:49pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/18 "2008-11-26T15:49:14Z")
Well, it’s also the temperature at which unicorns combust. Crazy, I know. ---
**Author:** ![masterofnone](https://avatars.discourse-cdn.com/v4/letter/m/4bbf92/32.png) [@masterofnone](https://boards.straightdope.com/u/masterofnone)\ **Post date:** [November 26, 2008, 4:10pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/19 "2008-11-26T16:10:02Z")
> [@TimeWinder](#): > > By the way, sterilization often _does_ require more than instantaneous boiling – you’ll often see instructions to boil something for at least X minutes to sterilize it. Not to pick on you specifically, **TimeWinder** , but I see this myth far too often, and it’s a pet peave of mine. Boiling does not sterilize water. Bacterial spores will survive up to 15 minutes at 250F and 15psi. Water never exceeds 212F by much unless under pressure. Purifying water by boiling it reduces the number of viable bacteria present. It will never sterilize the water. ---
**Author:** ![Anaglyph](https://avatars.discourse-cdn.com/v4/letter/a/ed8c4c/32.png) [@Anaglyph](https://boards.straightdope.com/u/Anaglyph)\ **Post date:** [November 26, 2008, 4:16pm UTC](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488/20 "2008-11-26T16:16:16Z")
> [@Washoe](#): > > What about enzymes? I remember reading somewhere once that there are enzymes which are deactivated at _exactly_ the boiling point of water. Is this actually true, and if so, why is it true? This is not true. Most enzymes denature at lower temperatures than the boiling point of water. On the other hand, hyperthermophilic bacteria (bacteria that live in hot springs and hydrothermal vents) had to evolve their enzymes to be functional at elevated temperatures. [Next page](https://boards.straightdope.com/t/whats-so-magical-about-the-boiling-point-of-water/474488.md?page=2)