Fastest way to boil water?

Question

When I want to make hot chocolate, one of the steps is, obiously, boiling water. It seems to take forever. Is there a faster way? The method I am currently using is putting water in a metal can and using the stove.

Answer 1

Use electric kettle (it takes only 1-2 minutes to boil the water).

If it's still too long, use the microwave for around 30 seconds to 1 minute (on high power). But be careful as water boiled in a microwave oven can suddenly "explode" (including your mug). And for safety please remember to choose the right a microwave-safe container (such as glass, ceramic, paper plates, wax/parchment paper) as microwaving in metal container (including aluminum) can produce sparks which can damage the microwave or even start fires.

For microwave method, we can read the following steps at wikiHow:

1. Pour the water into a microwave-safe cup or bowl.

2. Place a clean, microwave-safe object in the water (a non-metallic object such as a wooden spoon, a chopstick, or a popsicle stick).

   This prevents a dangerous problem called "super-heating" by giving the water something to form bubbles on. It occurs when water in a microwave heats water past its boiling point but the water is unable to form bubbles because there are no nucleation sites, causing a small explosion of boiling water (read more: Boil on Troubled Waters).

3. Put the water in the microwave. Heat in fairly short (no more than 1.5 minute).

4. If sterilizing the water, keep it boiling.

Check How to Boil Water in the Microwave for further details and safety tips.

Answer 2

Make sure you put a cover on the can. Not a tight cover; just something to keep the top of the water from losing heat (see this question).

If that's still not fast enough for you, you have a few options:

1. Leave a full kettle over a low flame all day long, turn it up when you need hot water. You just pay for the cost of the energy required to keep it hot, but can be dangerous if you let it boil dry.
2. Invest in an electric kettle. They're cheap, and will boil water faster than most stovetops.
3. Invest in an instant hot water system. Near-boiling water on tap whenever you want it. Safer than option #1, not cheap though.

Answer 3

Perhaps you're thinking about this the wrong way. Rather boil water quickly, try to have a large quantity of boiling/hot water on hand. Get a giant thermos, you can usually find these at Asian supermarkets. They look like this:

They'll hold about a gallon or more of water, depending on the model, and keep it near-boiling for quite some time. I use one at work so I can have hot tea on hand within seconds. And the water stays boiling hot for upwards of four hours.

Answer 4

You could go up-hill a few thousand feet...

Altitude            Boiling point of water 
0' (0m)             212 °F (100 °C)  
500' (152m)         211.1 °F (99.5 °C)  
1,000' (305m)       210.2 °F (99 °C)  
2,000' (610m)       208.4 °F (98 °C)  
5,000' (1524m)      203 °F (95 °C)  
6,000' (1829m)      201.1 °F (94 °C)  
8,000' (2438m)      197.4 °F (91.9 °C)  
10,000' (3048m)     193.6 °F (89.8 °C)  
12,000' (3658m)     189.8 °F (87.6 °C)  
14,000' (4267m)     185.9 °F (85.5 °C)  

---

If you're locked up and aren't free to go up the mountain, you could try this prison hack from:
The DIY Wizards of San Quentin. - Check the video in the link for a demo.

Prisoners aren't allowed to have boiling water because it can be used as a weapon, but for those that are tired of lukewarm instant coffee, there is a hack.

All you need is a little ingenuity, a plug with a length of wire still attached, and a piece of scrap metal. Put them together and you'll have a "stinger":

In case you're worried about how safe this is or if it would even work, you can buy pre-made stingers or immersion heaters:

---

On a more serious note...

You don't really need the water to boil to make hot-chocolate, coffee, or tea. You just need "hot" water anything over 180°F should work.

For Hot-Chocolate 140°- 160°F
For Coffee 205°F
For Tea 150° - 190°F, (depending on type and strength)

Note, most sources seem to recommend Not Using Boiling Water. Most coffees and teas turn out bitter with water that is too hot. Hot chocolate can have similar issues, especially recipes that include milk or cream.

Answer 5

Things I know will work:

• Use a thicker pot.

• Use a lid.

• Use less water.

• Use higher heat. Not extraordinarily high, but if you raise the heat it should boil faster. If the heat is to high this could damage the pan.

• Use a pan that covers the whole stove eye. If you have a small pan on a large eye, you are not utilizing heat properly.

---

Additional Info

Is it true that hot water freezes faster than cold water or that cold water boils faster than hot water?

"Cold water does not boil faster than hot water. The rate of heating of a liquid depends on the magnitude of the temperature difference between the liquid and its surroundings (the flame on the stove, for instance). As a result, cold water will be absorbing heat faster while it is still cold; once it gets up to the temperature of hot water, the heating rate slows down and from there it takes just as long to bring it to a boil as the water that was hot to begin with. Because it takes cold water some time to reach the temperature of hot water, cold water clearly takes longer to boil than hot water does. There may be some psychological effect at play; cold water starts boiling sooner than one might expect because of the aforementioned greater heat absorption rate when water is colder.

This appears correct, but I don't know I'm not a physicist.

Food52.com:

Keep the pot lid on. Use less water. Use higher flame. Use a thinner stainless steel pot (these are generally bad for cooking but they transfer heat really fast).

Use an electric kettle, or microwave (be careful) to boil the water and then pour it into your heated steaming pot.

Does water boil faster with the lid on?

Yes, water does boiler measurably faster with the lid on.

The reason is simple: in order to boil, water must be heated to the boiling point (okay, that was obvious). However, while heat is being introduced at the bottom of the pot, heat is also being lost at the top of the pot, through three means: evaporative cooling, and air convection of heat away from the surface of the water, and radiation from the surface (this last is probably the least significant).

Does water boil faster if you put salt in the water?

Yes and no. If you look at how fast water boils when you add a small amount of salt to it, such as when cooking your noodles, the change is insignificant between pure water and the salted water. However, if you take two identical pots and add one gallon of pure water to one pot and one gallon of 20 percent salt water to the other and heat the two pots on identical stoves, the pot containing the salt water will come to a boil first.

So salt won't really work.

Answer 6

For a given amount of water, you can do two things (both at the same time if you care to).

We can assume you always have your heat source turned up to maximum.

1. Divide your given amount of water into multiple containers and put each container on its own burner or heater.

Time to boil is going to be proportional to the volume of material you are heating. If you put half of your water on one burner and the other half on another burner, each will come to a boil in half the time it would if it were all in one pot on the same burner. (All things being equal - same burner heat output, same pot types,... Note that the container may need some time to heat up, too, but I ignore that here.)

2. Use a bigger container with more surface area. You can see this more readily if you are using a flame (gas stove), but some of the heat escapes around a small container. If you have more surface area to transfer the heat, this becomes more efficient. Switch from a pot to a frying pan, for example.

You can even see the importance of surface area efficiency in product purpose built for boiling, like the one from a company called Jetboil:

the secret to a fast and friendly design lies in increasing heat transfer efficiency

In this product, they increase the surface area with what they call the flux ring, and it's demonstrated in their video at the link.

But as a hack, just use a bigger pot and/or more burners.

Answer 7

Electric kettle has already been mentioned, this works very well for me.

A gas stove is a lot quicker than an electrical stove, at least in my experience. Personally, I wouldn't build my house with a gas stove just for quicker hot chocoloate, though. ;-)

Answer 8

A pretty fast way to make things hot would be to hover them over open camp fires. I ended up burning marshmallows in a matter of seconds as a kid when I attached them to a tree branch and hovered them over flames.

If you can take a pot of water and cover it and stick it in the fire and keep the flames going then you'll get it hot in no time.

Only other option would be to use lit torches around the pot, but if you do, PLEASE be careful and use excellent ventilation.

Answer 9

For best efficiency and fastest boil on your existing stove, you need to change a couple things. As noted in another answer, start by covering your vessel -- but use a metal pot (or can) big enough to just cover the burner element you're using, and put in only about 25% more water than you need (to allow for evaporation). Smaller pot wastes heat from the burner, larger means you're heating more water and pot than necessary, and same with too much water.

Now, turn the burner all the way up.

Normally, you shouldn't do this to make things heat or cool faster (an A/C unit, space heater, etc. won't heat or cool the room faster at maximum), but in this case, this will run the burner at maximum output, and since your just-right size vessel is capturing all that heat, you'll get the most heat into your water the fastest.

Now, as noted in another answer, don't wait for a full boil, use a thermometer to get the water to the right temperature for your bevereage and taste. Now, go have some hot chocolate.