Introduction: Make Crystal Clear Ice!

Picture of Make Crystal Clear Ice!

in this instructable I will show you how to make crystal cear ice without any special equipment! it is super easy! you will be surprised!

Step 1: Use Filtered Water!

Picture of Use Filtered Water!

the filtered water is much more pure and clean!
one of the things that causes the cloudiness of the ice is dust and
extra minerals in the water - the filtered water is much better for our clear ice!

Step 2: The Main Step! - Boiling the Water!

Picture of The Main Step! - Boiling the Water!

this is very simple but very effective!
- Boil the water , and than let it cool.
- after it is cool , boil the water again!
- this is it! you are done !
explanation :
the double boiling eliminates dissolved air in the water and decomposes minerals in the water ! dissolved air + minerals +dust
are the causing of the cloudy look!

Step 3: Results !

Picture of Results !

this is the difference between regular ice (cloudy) and the crystal clear ice- after following the process!

I hope you find this instructable useful and fun!

enjoy your crystal clear ice!


me (author)2007-10-09

when you freeze hot/warm water, it will freeze more quickly as regular cold water

btcarnovale (author)me2010-07-12

Let's do a "thought experiment". Start with two totally identical freezers. (This is a thought experiment, so they can be totally identical.) Take two identical containers. Put a sample of room temperature (let's say 70 deg F) water in one, and an equal amount of hotter (let's say 90 deg F) water in the other. Now put each of the containers in its own identical freezer. After some period of time the 90 deg water will have cooled down to 70 deg F. But in that same period of time the water that started at 70 deg F will have also cooled down. No matter what the period of time the water that started out hotter will ALWAYS BE PLAYING CATCH UP.  So it cannot ever freeze faster than the cold water.

BillK103 (author)btcarnovale2017-06-02

I read a good bit of this thread and saw how many people could be really insulting to each other, and I hope I do not come across so. The foundation of science is not education and expertise or arguing and definately not insults although those abound, it is experimentation, and full of unexpected results. One of the most unexpected I have seen is throwing a pan full of boiling hot water into sub-zero freezing air and getting an apparently instant conversion into what looks like snow but is probably tiny ice. Plenty of those on youtube. The same test with cold water and you get cold water. I have no idea why, but I expect it has to do with heat of vaporization and some magic occurring near the boiling point. (No not really magic). Someone cleverer than I will probably some day do some actual experiments and explain this apparent contradiction.

BillK103 (author)BillK1032017-06-02

Oh, I forgot to thank the original poster of this fine suggestion on making clear ice. Thank you, great idea.

zmarsh (author)btcarnovale2011-06-29

The hot water is hotter and it will need to cool down more, but it still cools down faster. It's possible that they will both be ready at the same time

btcarnovale (author)zmarsh2011-06-29

OK, for the sake of argument, let's assume that hot water reaches 0 C sooner than the same amount of cold water. (This eliminates having to deal with the non-linearity of crystal formation.)

so if TH is the length of time for the hot water to reach 0 C, and TC is the length of time for the cold water to reach 0 C, and DT is the difference between those times, then

TC > TH ________because the cold water takes longer to reach 0 C, and

DT = TC - TH ____DT is how much more time it takes for the cold water to reach 0 C than it took for the hot water.

But since the hot water starts out at a higher temperature than the cold water did, the hot water will at some point in its cooling reach the temperature that the cold water started at. Let's call this time D. From there, the amount of time for the hot water to reach 0 C should be equal to TC, the amount of time for the cold water to reach 0 C. At this point in time the hot water has cooled to exactly the temperature that the cold water started at so from here it should take that same amount of time to reach 0 C.

Now we can represent the amount of time for the hot water to reach 0 C as:

TH = D + TC ______Because the hot water MUST at some time go through the temperature that the cold water started at.

Now substitute the right hand side of the second equation for TH in the first equation.

DT = TC - TH

DT = TC -(D + TC)

DT = TC -D -TC

DT = -D

But DT and D CANNOT be the negative of each other because they are both positive numbers representing durations.

So TC cannot be larger than TH.

Furthermore, TC must be larger than TH, because if they were ever equal that would mean that D were 0, i.e., at some pair of hot and cold temperatures, the hot water would have to cool INSTANTANEOUSLY to the lower temperature.

grino (author)btcarnovale2011-10-14

Call me in the winter when your hot water lines burst before the cold ones . Sorry no fancy formulas just plain simple reality . I am a 3rd degree black belt in plumbing waterology have phd in turdherding. Ask any pumber or heating guy and he will tell you the same thing only in plain english . Hot water will freeze quicker than cold .

jaybe3305 (author)grino2015-04-19

Hot pipes freeze fast in cold because of flow. there use much. Less than coldwater pipe site for hours without use hot water flow.just think when go get glass of water in nite or flush. That coldwater. hot water pipes calls you get let guess In basement is where they fail most homes with basement are colder by 10 - 15 deg and in a drift and u get to make $$$

btcarnovale (author)grino2011-10-14

LOL. Good thing I spent my career doing simple things instead of plumbing.

The next time you see a picture taken by the Hubble Space Telescope, THAT was the kind of thing I did for a living until I retired. (And NO, I was not involved with the flawed optics. I worked on the spacecraft itself, not the payload.)

RandyL4 (author)btcarnovale2015-04-08

I might be a bit late to this game but if you where a Aerospace engineer you must have been a very bad one who skipped a lot of science classes.

zmarsh (author)RandyL42015-04-08

Just a wee bit late, my last comment was 3 years ago :P

capt_skinny (author)btcarnovale2011-09-27

TH = D + TC ______Because the hot water MUST at some time go through the temperature that the cold water started at.

This step contains the logical leap. Yes, the hot water temp MUST at some point be equal to the initial cold water temp, but those are temperatures. It's an assumption to say that the rates of temperature change will also be equal at that point.

btcarnovale (author)capt_skinny2011-09-27

If you are going to assert that the rates of change will be different, the onus is on you to provide a reason for that to be the case.

capt_skinny (author)btcarnovale2011-09-28

I'm not asserting that the rates of change will be different. I really don't know. I'm asserting that it's an assumption to conclude they WILL be the same merely because the temperatures will be the same.

btcarnovale (author)capt_skinny2011-09-28

My assumption is based on the foundation of scientific inquiry. I.e., that two identical systems will consistently behave in the same fashion. That's why different groups will repeat experiments done by others to verify that the same result is obtained.

If you think that my assumption is unwarranted, the onus is on you to provide some reason why you think that is the case.

I also assume that the force of gravity will remain relatively constant throughout the course of my day (subject to the known variations due to irregularities in the distribution of the Earth's mass).

Would you also question that assumption? If so, why? If not, why do you question my assumption that two identical pans of water in identical freezers will freeze at the same time?

i'm guessing you didn't take chemistry when you posted this. actually, water that is 90 degrees has more energy than water at 70 degrees. for the most part, you see that this follows logic and common sense. the freezer, let's say, is at 0 degrees, just for simplicity.

now, think about diffusion, more specifically entorpy: movement of heat from a higher "concentration" source to a lower concentration source. this movement can be facilitated/sped up by larger differences in concentration.

since water at 90 degrees has a larger energy difference with a 0 degree environment than water at 70 degrees with a 0 degree environment, the water at 90 degrees will actually freeze faster, because the heat in the 90 degree water will diffuse/escape from the water much more quickly as a result of entropy.

vaderj (author)TheChemist1232014-02-25

Sorry Chemist123 - I know this comment is a little late but I just performed the experiment, MythBustsers style, and your interpretation of "entorpy" (which I am assuming is supposed to be entropy, the description of the universal preference for disorder over order) proves false. I filled two trays of ice, both trays from the same manufacturer (Rubbermaid), one tray with 60 degree water, one tray with 100 degree water (+/-5 according to my laser thermometer) both side by side on the same tray of my freezer (0 degrees according to the thermometer) and, believe it or not, the "cold" tray of water froze first (at 30 minutes it started to freeze over, with an average surface temp of 27 degrees) while the "hot" tray had an average surface temp of 37 degrees.

Oh, and I boiled both samples of water for 10-20 minutes - the cold one I stuck in the fridge and stirred with glass drink mixer on occasion until the average temp cooled to 60, while the "hot" water I let cool in a covered pot on the stove until the cool one was 60.

But who cares - I'm just some idiot who was dumb enough to be fooled by internet tomfoolery. There may be some combo of temps that can accomplish the described effect, but the required temps would have to be very narrow as to make the effect unnoticeable :

The water at 90 will certainly be cooling off faster AT FIRST. But at some point the 90 degree water must be at 70 degrees.

Are you claiming that once the 90 degree water reaches 70, that it will then cool faster than water that simply started at 70?

Thought experiment:
Put 90 degree water in one freezer. Wait until it reaches 70. At that instant, you put some 70 degree water in another freezer.

Now you have two freezers, each with an identical container of 70 degree water.

What happens now? Why/how would the water in one freezer cool faster?

In my response to zmarsh below I attempted to encapsulate the above argument in a rigorous fashion. If there's an error in the math or logic, please point it out to me.

(And BTW, I was a double major math-chem until midway in my junior year at which time I realized that math was the place for me.)

LOL.Good thing you switched to math. Hot water can freeze faster than colder water under certain conditions. It is called the Mpemba Effect. Rather than write a dissertation here just take the time to Google it. It will enlighten your mind.

I have Googled it, and I have noted that every attempt to seriously defend it includes a lot of verbal "hand waving". The Wikipedia article says it best "There are no reliable sources that indicate exactly how to demonstrate the effect and under exactly what conditions it occurs."

If you're willing to believe in something like that, maybe we should talk about a bridge that I have for sale.

As a college professor myself (Electrical Engineering), I tend to rely on research that either supports a hypothesis or does not support it. Instead of a simple Google search do a "Google Scholar" search. It is at the top of the search page under "more." There you will find nothing but scholarly research on the subject. You will find it has been throughly researched and found to be true (hot water freezing faster than cold water) under certain conditions. The experiment has been repeated many times. BTW, the reason Wikipedia articles are not allowed in college research papers is because ANYONE can write an article or edit it without any real knowledge of the subject. I wouldn't bet the farm on the information you find at Wikipedia. However, if you would rather believe Wikipedia than Harvard, The American Physical Society, and the American Journal of Physics then that is your call.

GummiBear (author)btcarnovale2012-02-09

I know a saying that is... "Heat goes where its HOT to where its NOT"..., and because the water is hot and the water and air around it is coooold, it will leave very fast (because it has a lot of potential energy) and drop to a temp lower than the 70 degree one. Say, 60. Then they will freeze at a normal rate, and guess which one freezes first? ( I am just a 6th grader so thats all i know...)

Not quite. The fallacy here is that water (or anything else) doesn't cool in leaps. It doesn't cool down 30 degrees, then stops, checks its own temperature, reconsiders what speed of cooling would be apropriate, and then continues cooling at the new speed.

What it actually does is it cools down in really really tiny steps (infinitesimally small for the methematically minded). So it cools one really small step (it's not an actual step even, but it's easier to imagine if you view it as tiny tiny steps) and then cools another tiny step and so on, and the speed changes in equally extremely small steps. Now if you imagine these steps to become as small as they could possibly be you will see that the speed changes CONSTANTLY.

To sum up, once the water that was initially 90F reaches 70F it will at that point cool exactly as slowly as water that was 70F to begin with. Same with water that started at 95F or 110F or 75F, because the speed changes constantly and in tiny steps, not in big leaps and will always reach the same value at 70F.

You can imagine it a bit like the shape of a skateboard halfpipe (slow,gradual change in incline) vs stairs (flat, then a drop, then flat again and so on).

SumGie (author)btcarnovale2011-08-04

The error is that freezers have thermostats.
The compressor cycles according to the internal temperature of the freezing chamber. When you put more heat into one freezer than you do into the other, you trigger the thermostat to turn on the compressor in that freezer faster. There is hysteresis. *(did I spell that right?) in this process. The freezer puts more effort into removing heat than is needed to achieve freezing. That freezer will temporarily get colder than the other one. So the hotter water has more effort applied to removing its heat than the cooler water does. It can, therefore, indeed be frozen sooner.

If you were simply using a heat sink (such as a quantity of existing ice) to remove the heat from the water, this would not be so, but since you are using an active system, it is.

prioret (author)btcarnovale2010-07-14

Your assuming that water freezing is a Linear process. Its not. Phase changes and crystal formation are non-linear. Do a quick search on Mpemba Effect before you do your thought experiment.

kricketone (author)btcarnovale2010-07-13

well it does here hummm shot a hole in your logic .

Bas (author)me2012-04-15

He means "when I boiled water and got rid of the gases that were dissolved inside, its freezing point came up to near zero it froze easier"

pdub77 (author)me2010-07-12

Not true. Anything warmer takes longer because it requires more energy and therefore more time to reach the freezing point.

qualia (author)pdub772012-02-09

Not true. Anything warmer takes longer because it requires LESS energy and therefore more time to reach the freezing point. the positive energy input is applied to the freon, not the water.

just felt like contradicting someone on this glacial movement towards a eureka moment. dont take it personally.

spent three years plumbing before i decided an obligation to clear drains is not a recurrent theme i wanted in my life.

pdub77 (author)qualia2012-02-10

I don't think I agree with your logic. Not about the drains, but the energy being applied to the freon. I agree with the drain part. As for the contradiction, doesn't the water require more energy and therefore the freon as well? Isn't it all in the same system with the same goal in mind? More energy applied to freon is specifically because the water is warmer and therefore requires more cooling, right?

Or do you mean that the energy (in the form of heat) must leave the warm water?

qualia (author)pdub772012-02-11

Nah its just the grammar in the sentence left it open about what the subject "anything warmer" represented. I was tired, this was a featured instructable and i didnt realise the comments were this old at the time. What you meant after the above comment is now as clear as ice (the boiled kind).

pdub77 (author)qualia2012-02-11

HA! Cheers, man.

prioret (author)pdub772010-07-14

Look up Mpemba Effect.

pdub77 (author)prioret2010-07-14

This may be true for a very specific set of variables. I will concede that. As a general rule of thermodynamics, however, I stand by my original statement. I am no scientist, though, so I could be wrong on most anything. (not that scientists couldn't be wrong either. . .) = ) (author)me2007-10-09

Not exactly. No matter the temperature of the water, it will freeze at the exact same speed if placed in the same freezing environment.

finfan7 (author)podup365.com2007-10-10

Actually that is only technically true. Technically all water freezes at the same speed: the crystalization speed of water. What me is talking about is that warm water placed in a freezer will achieve total solidity faster than room temperature water in the same freezer. (author)finfan72007-10-10

Can it happen? Yes. When this does happen it is a phenomenon known as the "Mpemba Effect". A phenomenon that took a college chemistry lab to prove exists. This phenomenon is extremely unlikely to be repeated inside of a home freezer while making ice cubes.

I read the article you linked and couldn't find a description of the specific conditions under which hot water can freeze faster, though it asserts repeatedly that there are such conditions. Do you know what they are -- that is, how to make hot water freeze faster? I'm (obviously) skeptical. If you've done the experiment, it'd be a super-cool instructable.

sithkhan (author)The Real Elliot2007-10-11

The concept is that hot water (above 75 C IIRC) gives off more heat energy than cooler water, thus it lowers in heat energy more rapidly than cooler water. Due to the poor thermal retention of water, there exists a temperature at which water above that temperature will release heat energy more rapidly than a similar mass of water at a lower heat energy level.

The Real Elliot (author)sithkhan2007-10-11

What you're saying is true, but doesn't provide the effect. The hotter water may cool down faster initially, but it'll eventually cool down to the starting temperature of the colder water, at which point it'll only be shedding heat as fast as the cold water was to begin with. The water has no memory of what temperature it used to be, so you've effectively given the cold water a head start. The formerly-hot water, being cold water now, can't catch up to the cold water, which by now is really cold. The best explanation for such an effect I've seen is that the hotter water spends more time evaporating/steaming in the freezer, and thus when it reaches the lower temperature, there's so much less of it left that it can freeze down to 0 degrees faster. But you're not freezing the same amount of water, so it's kinda like cheating. And if your goal is to make ice-cubes, for instance, you've made less ice and have to defrost your freezer sooner. That's a lose. Anyway, not to threadjack. Cool clear ice trick.

greyhuk (author)The Real Elliot2012-02-09

Part of it is also convection. If you put ice cubes in water they dont melt fast. stir and it gets cold quick

_soapy_ (author)The Real Elliot2007-10-14

I think there is some misunderstanding here. pod365, it's called the Mpemba Effect after the kid in an African secondary school who first wrote it up - hardly something beyond most of us at home! Wikipedia: -- The effect is named for the Tanzanian high-school student Erasto B. Mpemba. Mpemba first encountered the phenomenon in the classroom of Eugene Marschall at Mkwawa Secondary (formerly High) School, Iringa, Tanzania, where Mpemba was a student. Eugene Marschall, a member of the Teachers for East Africa/TEA program, taught chemistry and physics at this school from 1965 to 1967. Mpemba first noticed the effect in 1963 after his account of the freezing of hot ice cream mix in cookery classes, and went on to publish experimental results with Dr. Denis G. Osborne in 1969. -- The exact mechanism is unknown, but I think my explanation is correct. The rate of cooling of a warm or hot water bottle placed into a freezer is faster than a cool/cold water bottle placed into the same freezer. This is because the hotter (still) water has a far stronger convection current, and so it moves more rapidly around as the outer layers cool, moving the warmer core outwards. This doesn't happen in the (still) cold water, where the internal heat has to conduct outwards. The effect of the convection is to act like a self-stirring mechanism, which transfers the heat from the entire mass of the water far faster than a still mass of water does. And, further, because ice and water are actually pretty good insulators when not allowed to convect (much like air) this means that the cold water will still be liquid in the middle of a large block (because it freezes slowly from all sides) long after the warm water reaches the freezing point, and freezes solid all the way through. Add to this the way that phase changes occur (and the release of energy when changing from a liquid to solid state), and it is actually fairly easy to explain. (author)_soapy_2007-10-14

Yes, all of your post can be found in the link I provided in a previous post. It really isn't easy to explain, duplicate, or proven outside of exact conditions in a lab. Mpemba first considered this phenomenon with milk in high school, which has far different properties than water. It wasn't until college that he made his theory based on findings in a lab. Also, it isn't easy to explain, else there wouldn't be such disagreement about it among the experts and amateurs alike. All things being equal, the hot and cold water is going to freeze at the same speed. The hot water only "appears" to freeze faster or the environments are different. A counter theory holds that the ice tray holding the hot water makes a better contact with the freezing element of the freezing mechanism and thus freezes faster. I think it's not worth the time or energy used to boil/heat the water. A person is better off just buying a commercial ice maker for their freezer. :)

_soapy_ (author)podup365.com2007-10-15

Of course this is all academic! I've been reading quite deeply into this effect, and there is no definitive answer. All the "answers" are simply lists of all the possible mechanisms for how this could occur. However, listing the 20 or so different ways that hot water in a tin is different to cold water in a tin is not an answer! However, if you want to try it, get a could of dataloggers, and go for it. I'd suggest you heat one tray to 212F / 100C (boil) and the other should be likewise boiled, but allowed to cool to 135F / 57C before you start. This, apparently, gives the greatest result. Use about a cup full. Hope this helps, I might give it a shot myself, but I'm too busy at the moment. (Indeed, I should have left ten minutes ago!)

geekazore (author)_soapy_2007-11-02

I believe the reason the hot water freezes "faster" is because the hot water trips the thermostat of the home freezer longer/more often. Not a exactly "green" process. If both trays are in the same freezer, the freezing times will depend on the capacity to cool (i.e tiny icebox or industrial freezer.). The hot water may freeze a bit later as it has more specific heat. The boiling bit may also prolong freezing as a few of the materials that may assist nucleation have been boiled off. Just my thought to toss in the pool here. Maul it as you see fit;-)

VictimDub (author)geekazore2007-11-23

One reason for hot water freezing faster (if not contained, i.e. a bottle of water that is closed) is the evapration amount, you will actually have less water in the hot water tray then in the cool water tray, this coupled with currents could definatly make it cool faster.

frogman5452 (author)VictimDub2008-01-30

You could start off by having an exact weight for both the hot and cold water. Then after freezing weigh them again. If evaporation is happening to reduce the amount of water needing to freeze the hot water start should weigh less.

Wow. Lots of comments

erqua (author)_soapy_2010-03-08

How about this? Look at how thermostats in freezers work. When the temperature reaches X1 degrees, it starts the compressor. When it reaches X2, the compressor turns off. X2 is a few degrees below X1. There's a small range between X1 and X2.

Both freezers starts with their temperature somewhere between X1 and X2. When you put hot water in the freezer, it raises the temp above X1 and compressor kicks in. This then reduces the inside temp of the freezer till it is just below X2. At this point, this is a bit lower than the other freezer, so the water freeze faster.

finfan7 (author)erqua2010-03-08

That's an interesting thought but someone from the colder climes will have to test it for us.  Anybody from Canadia paying attention here?

About This Instructable




More by isr_Raviv:Make a safety pin from a paperclip! Improve your digital camera extremelymake crystal clear ice!
Add instructable to: