# Make Hot Ice - the Complete Guide

57,043

54

46

The complete guide to making hot ice and sodium acetate. How to create it, fix it, and use it. All methods from baking soda and vinegar to laboratory synthesis are shown.

The basis for hot ice is sodium acetate trihydrate, which is heated above its melting point and then cooled below its melting point so it's supercooled. It's still liquid and quickly solidifies when a seed crystal is introduced.

Sodium acetate trihydrate can be bought, or made at home by mixing three tablespoons of baking soda with one liter of vinegar and boiling down.

The video shows a detailed step by step instruction on how to do this as well as how to fix problems you might have.

### Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

## Recommendations

• ### 3D Printing With Circuits Class

6,867 Enrolled

## 46 Discussions

but its not working..

Crystals, such as ice, cannot form without either a disturbance in the liquid causing the crystallization bonds to form, or another crystal already formed for the liquid to build off of.

hi sorry to ask again but I wanted to make this to demonstrate to my sisters primary school kids, and not working very well. I keep reading other instructable pages and they all do it totally different. for example:
You use 1litre vinegar to 3tbls bicarb soda. i have converted but Indigoandblack uses 1 gallon (3.7l) vinegar to 12 oz ( 20 tbls ) bicarb soda.
Why does he use so much more bicarb soda? and is this why with me using 3 tbls my hot ice is not solidifying but going mushy? i also read in other sites that you don't have to worry about measurements, more so add until supersaturated, so keep adding the bicarb soda until the bubbling reaction stops. thanks

ok, really confused now, as mine not working so trying to work out why it is going mushy and not freezing solidly. i just read the instructable by c.stokenbury -
Why does he do your steps, filter it, dry it to get left with the crystals then take the sodium acetate crystals and dissolve them in boiling distilled water?
I get it if he started with concentrate acetic acid, but if he started with vinegar that already has water in it, why is he doing an extra step with water?

ok, first one i put in a water bath of 1C. it turned to mush. i thought it turned to mush because the temp of bath was too cold, didn't even have time to take temp of sodium acetate. I saw you said add more vinegar, so I did. supercooled it down to 16C and it just wouldn't crystalise. I notice that my vinegar is cloudy and has sedimentation which it says on label is normal. would this be contaminating it. where else can i get vinegar apart from supermarket, is there a better one? To start with my liquid boiled down so only about 5 % was left before the film started. What am I doing wrong? I can see loads of flecks and bits in my solution, I am thinking the vinegar has particles in it. Would using the charcoal help with this?
Thanks

heres a clever idea to reduce the chances of burning the acetate, when you are boiling it to remove water,

freeze your vinagar, almost before use,

vinegar i beleive has a high melting tempurature, and will form crystals well before the water freezes.
simply put into the freezer until the tempurature drops below 16 degrees celcius, then scoop out the crystals , but include a small amount of water.

this will be about 70-90% vinegar, and will yeild just as much sodium acetate, but will require less boiling, and shorten the time you risk burning the vinagar.

This sounds like a great idea. I wonder what NurdRage thinks of it. He demonstrated a few methods, but not this one. It seems to me that freezing the (clear) vinegar should work, but I'm an amateur.

Thank you for the outstanding video. I can see you put a lot of time into it. I've been struggling with this one and haven't succeeded yet. Mainly because I've been hacking at it and not following the instructions closely. Thank you for saying "this is a tricky one". I find it frustrating when on YouTube it looks easy but in reality it's complicated. If it's complicated then the speaker should say so. If I still choose to try, then at least I know it's a tricky one.

There is extra info in here about the specific composition of the heat packs and recharging (though that is not the primary topic of the paper)

http://www.motiva.fi/files/929/master-s-thesis-mikko-keinanen.pdf

Awesome video: able to do it first time:mine was a gentle amber colour.

I did this and it worked the first time :) Thank you. But it ended up being the white color of the high quality hot ice , not brown as shown in the video.

I have preformed this several times, and I must say, this video is excellent!! The walk through is clear and in great detail. Thank you for a great instructable!

Instead, just make the hot ice but when you boil it as you get close to the crusting stage turn down the heat and boil it very gently. The less burning the less browning you'll get.

you can still distill the vinegar if you want, but i think its too much of a hassle compared to just gently boiling it.

i never get to the crusty film part of the boiling and i am too lazy to let it evaporate in the air. what am i doing wrong?
i divided the ingredients by 3 so its 1/3 liter 5% Vinegar(Distilled white) and 1 tbsp of baking soda and added baking soda untill it dtopped reacting, and made sure it was clear. thne i started to boil and waited an hour to see the film, but i get nothing. i need great help because this is a very simple chemical to create, and i can make copper carbonate, nickel carbonate, copper acetate, nickel acetate, copper sulphate, and some solution with polyacrylamide