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ice cubes made from stone - do these work?

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  • Sasha Aug 2, 2005 08:41 PM
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I was looking in a Japanese magazine that featured cups and such made from stone. They were selling small ice-cubed shape stones. A dozen for $30. The picture in the ad featured a cocktail with these stone ice cubes.

Do these work? Benefit would be I could throw away my ice cube trays and no longer deal with watered down drinks.....

the ad said that the beer mugs kept the beer very cold. I may at least buy one of these. The beer mugs were $50.

to buy or not to buy, that is the question.

help fellow chowhounds.....

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  1. No. Here's why:

    Let's assume that the stone "ice" cubes are made of granite and are 1-inch square (I'm going to work the rest of this explanation in SI [metric] units because it's easier and those are the units I use every day - a cubic inch is equivalent to about 16 cubic centimeters [cc]). Let's assume further that you have one of them, which has been kept in your freezer at minus 15 degrees C (more or less zero F) and you want to use it to cool a 100cc glass of water at room temperature (which we'll define as 20 degrees C). Let's also make the simplifying assumption that adding the cube to the drink doesn't change the overall mass of the system - it remains at 100 cc (which, for water, is also 100 milliliters and 100 grams).

    The specific heat, which is a measure of how much heat a particular material can hold per unit mass, of granite is about 0.2 (water is defined as 1.0), which means that 0.2 calorie of heat is required to raise the temperature of 1 gram of granite by 1 degree C, and the specific gravity of granite is about 2.6 (again, water is defined as 1). If we multiply all that together, that means that the granite ice cube requires 8.5 calories of heat to warm up by 1 degree C. When you put it in your drink, it absorbs that heat from the 100 cc of water, so how much does the water cool down? Well, there's 35 C degrees difference between the granite and the water, so the granite will absorb 35 X 8.5, or about 300 calories, which will cool the water by about 3 degrees C (one calorie of heat removed from 100 cc of water will cool it by .01 degree, so .01 X 300 = 3 degrees).

    Now let's work the same problem with water ice, instead of granite, all other conditions being the same. The water has a specific gravity and specific heat of 1.0, so the 16 cc ice cube will absorb 16 calories of heat per degree C of warm-up, which means (all things being equal, which they're not, as I'll explain in a second) it will decrease the temperature of the glass of water by 16 X 35 calories, or about 5.6 degrees C, nearly double the granite.

    But here's the kicker, and this is the big difference: as it absorbs heat, the water ice not only warms up, it also melts, and as water goes from solid ice at 0 degrees C to water at 0 degrees C, there is additional energy required and it's substantial - 80 calories per cc, so in addition to the 16 X 35 calories needed to warm it up, there's an additional 16 X 80 calories required to melt it, for a total of 16 X 115 calories, which is sufficient to cool the glass of water by a whopping 18.4 degrees C (as compared, remember, to only 3 degrees C for the granite).

    So, it's really the heat of fusion that makes ice such a good cooler of things, and that only kicks in as the ice melts. Melting granite would also release it's latent heat of fusion (and I don't offhand know how many calories per gram that might be), of course, but that occurs at a temperature that's of less interest for cooling drinks.

    26 Replies
    1. re: FlyFish

      you are my Chowhound Science God.

      Thank you for saving my some $$$$$. I will invest in some more ice cube trays.

      1. re: FlyFish
        j
        Just passing by

        AWESOME freaking post!

        1. re: FlyFish

          So, does hot water freeze faster than cold water?

          1. re: rudeboy

            This one's easy. I'm sure you're teasing, but I've heard so many people who believe it.

            Say you put 100 degree water in an ice cube tray. At some point in the freezing process, the initially hot water will pass through 40 degrees on its way to freezing. At that point, it will be just like having put 40 degree water in the freezer, but you'll have used energy from the freezer to get it to that temperature.

            The unknown here is if water evaporates off the hot water after being placed in the freezer, leaving less water volume to freeze, allowing it to freeze more quickly from that point on. But if that's the case, just put less water in your cold water ice cube trays to begin with, if you don't care about smaller ice cubes.

          2. re: FlyFish

            Informative post of the year! (right up there with the Singapore Pepper Crab one from a few months back)

            Alton Brown would be proud, not just MIster Science, not to mention any high school Physics teacher.

            1. re: FlyFish

              I can't back up my answer like you did, but I would agree.

              Do not buy those ice cubes.

              You will just have to trust me.

              1. re: Tugboat

                Maybe you could experiment with some regular rocks. They're plentiful and free. On the other hand, the hell with it.

              2. re: FlyFish

                OK Flyfish, I am impressed. Now, please answer me the question of how to make clear cubes in a home refrigerator freezer. They are so much prettier in a scotch on the rocks. Thanks

                1. re: Roy

                  try using distilled water... I think it is the calcium, etc. in tap water that makes the cubes cloudy.

                  1. re: Roy

                    Here's where the hot water in the ice cube trays comes in -- to make clear ice cubes, start with hot water. Can't tell you why it works, but it works.

                    1. re: DanaB

                      Correct. It's the air dissolved in the water that makes ice cubes cloudy - as the ice forms the air creates bubbles. There's less air dissolved in hot water (even less if you boil the water), so starting with hot water creates fewer bubbles as the ice forms.

                  2. re: FlyFish

                    I own a set of these stone ice cubes and they work just fine. So, your math and physics look pretty slick but it would seem that there is an error somewhere.

                    1. re: bugmenot

                      I read the explanation above but I was waiting for someone to mention they used the stones. It seems pretty reasonable that if a cold mug can make a beer cold, why wouldn't a stone?

                      Sure there's questions of surface area, how long it takes to get cold, efficiency but my guess was they would work...just like heating up a rock in a fire and dropping it in water heats the water. Not the best method but it works.

                      Regarding effiency, I could see if you ran a freezer for only the stones, it would be a waste...however placed in a freezer that is going to run anyway, it's on the benign side.

                    2. re: FlyFish

                      I get it, but I have to tell you that my eyes began to cross uncontrollably about half-way through.

                      1. re: FlyFish

                        Okay... found this as the top result for "do soapstone ice cubes work?" and so even though it's a necro, figured I'd respond to make this (at least appear) a bit more accurate.

                        Trying to sort out the FlyFish math for granite, using the Wolfram Alpha information at http://www.wolframalpha.com/input/?i=..., we find that granite has a density of 2.6 g/cc and specific heat of .28 joules per gram degree Celsius. So, we multiply our total volume of 16 by specific heat and density... so 16*.28*2.6=11.648 as our total. Supposing 35 degrees of temperature difference, we're looking at 407.68 giving a total temperature drop of 4 degrees before the granite cubes become the same temperature as our water.

                        But that wasn't the question... the question was about soapstone ice cubes. Using Wolfram Alpha again, from http://www.wolframalpha.com/input/?i=..., we find that soapstone has a density of 2.65 g/cc and specific heat of 1.12 joules per gram degree Celsius. Using the same math we just did, we multiply 16*1.12*2.65=47.488 as our total. Again supposing 35 degrees of temperature difference, we're looking at 1,662.08 giving a total temperature drop of 16.6 degrees before the soapstone cubes become the same temperature as the water.

                        Let's summarize. If our 1 CI ice cube actually does give 18.4 degrees of cooling, this makes a fully melted ice cube at equivalent temperature about 11% better than soapstone cubes for cooling. That being said, it waters the drink and the ice cube always starts at 32 degrees F or 0 degrees C. Our sandstone cube may, depending on the freezer, get lower, giving it more degrees of cooling possible. If your freezer cools to 22 degrees F, instead of 35 degrees of temperature difference we're looking at 45 degrees on the soapstone, giving us 2,136.96 calories for 21.4 degrees before the cubes become the same as water, and making the stone cubes actually better. In fact, at anything 5 degrees Fahrenheit or greater below freezing, the soapstone will cool more than ice.

                        Simple math. Right?

                        Anyways, summary time:
                        Skip the nordic cubes. Granite is not a good choice.
                        Soapstone cubes are decent. If your freezer is cold, they become awesome.

                        1. re: Maymne

                          I just ordered the soapstone cubes for my single malts. Haven't used them yet but don't see why they wouldn't do exactly what they're supposed to. Of course, I am neither a math nor physics major -- just a drunk.

                          1. re: Maymne

                            " the ice cube always starts at 32 degrees F or 0 degrees C"

                            what makes you think once Ice freezes that it STOPS decreasing in temperature?

                            Ice continues to drop in temperature just like any other form of matter, until we get to absolute zero(or as close as possible).

                            Ice machines such as Kold Draft churn out large cubes that are at or about -40F and require a much different approach to cocktail making than standard ice machines(which tend to make ice at or about 0F.)

                            1. re: nkeane

                              True. The science did somewhat break down... that's the problem with trying to math and logic at the end of a long holiday.

                              If I'm understanding properly, since soapstone has a higher density and specific heat than water, the ice will have a max cooling of (80+temperature difference between ice and liquid) multiplied by the amount of ice, so 16 in our example. With the 45 degree difference, ice would be (80+45)*16=2000 or 20 degrees. Soapstone should do (1.12*2.65*45)*16=2,136.96 or 21.3 degrees.

                              That means it takes 41 degrees F of temperature difference between liquid and cubes before soapstone gets better than ice. Which should still happen, but... extra degree down, 6 instead of 5.

                              1. re: Maymne

                                for such a slight difference in outcomes, it seems a silly endeavor. That said, the dilution you speak of as it pertains to ice, is actually a desired thing! Water opens spirits up and allows you past the burn of Ethyl alcohol so you can taste all the delicious flavors you are looking for.

                          2. re: FlyFish

                            I dont know the science of it, but I bought a pack of soapstone cubes. they are like small dice and simply cut and not sanded at all. they are more porous than sanded stone and I think the size and porous factor make them pretty useless. I have started carving soapstone as a hobby and thought, maybe size does matter and have tried experimenting with stone size. I can tell you that a stone the size of 3-4 times the small cubes chills whiskey both faster and longer. I then sanded the stones to a very smooth finish with some 320 and then 1200 wet sand paper. the cubes then worked even better than they did before sanding. they were also much easier to clean as well.

                            so, if you want whiskey "on the rocks" use soapstone that is more like rocks than dice. I am going to test cutting rings next. I'll try and let you know how the next experiment goes. :-)

                             
                            1. re: o2cui2i

                              As another reference............the soapstone cubes I have are 3/4" and appear to be sanded slightly. Six cubes, soaked in water and frozen, will cool down a double shot of Scotch but won't get it as cold as a couple of ice cubes left in for even 30 seconds and removed. I assume this is because there's no appreciable dispersion of cold water from the cubes.

                              1. re: Midlife

                                the smaller the stone, the quicker it's core temp will be changed by the whiskey. if the whole stone is 0 F and the whiskey is 70 F, the whiskey will warm the outside of the stone as the stone cools the whiskey. it's about having enough mass so that the stone is not meeting the whiskey, but instead large enough to keep the whiskey going down to it's temp. I cant tell you the exact numbers, but I can say as a fact that a larger stone cools better. my glass got cool, so the larger stone has got to be doing it. the small ones dont do anything but look like square rocks.

                                1. re: o2cui2i

                                  Unfortunately the only 'rocks' I've been able to buy are all this size.

                                  1. re: Midlife

                                    if you want to have some fun, find a place that sells raw soapstone. just dont get anything minded in California(might have asbestos) all you need is a junk to cut into the size you want.

                                    you can just cut it with a hacksaw blade and shape really easily with files. use wet sandpaper to get a nice smooth finish. then just freeze and use. soapstone is not that expensive... you might even have a mine close to you??

                                    this is my latest little art flair...

                                     
                                    1. re: Midlife

                                      two stones, it dropped the temp from 21C to 16C in less than 30 seconds and when I checked after 10 minutes it was still only 17C. so a little bigger stones might cool it even more before the core temp matches the whiskey, but having them meet around 17 degrees is not bad. :-)

                                       
                                       
                                       
                              2. re: FlyFish

                                Not to knock you Mr or Ms FlyFish, I found this interesting and this actually made me smile. Reminds me of last week when one of our users who wanted to buy a new computer asked my boss, who is a very bright IT guy, if she should buy the i7 Ivy Bridge or the much cheaper 3.33ghz core 2 duo.
                                She got the whole dissertation on the metrics of i7 vs the c2d for about 20 mins when all she wanted to know was, will the one that costs $600 more go that much faster when she hit the button for her email :-)
                                Heck, you could put water in balloons and freeze them and it would keep them cold. Chill the glass. Chill the Scotch. (Why do people not do this?) Heck, anything can keep stuff cold for a while. By the time the stones stop keeping your drink cold, you should be on your way to a second drink anyway.
                                Drink faster. That is the answer, unless you like to nurse one drink all night. Then you might want to pass your Scotch through some liquid nitrogen every so often. Personally, I do not like to chill a good top shelf as I think it dulls the taste buds. Technically, I can't tell you why, but I think it does. :-)

                              3. Those beer mugs that you freeze, made of plastic with water between the layers, make for an awesome cold beer in the summer at the cottage. Not very classy, and most beer probably shouldn't even be served that cold, but... your beer actually gets colder as you drink it, on a hot summer day!

                                1. Wouldn't those stones break your glasses? Why not just buy some plastic ice cubes?

                                  1. First time seeing this post and answer(it is almost 4 years old) but I think the reason that the explination apparently doesnt match reality is for one simple mathmatical mistake. When we talk casually about calories, what we are actually talking about is Kcal, or kilacalories. Which is to say that one Calorie is actually 1000Kcal. It takes 1 Kcal to raise the temp. of a cc of water 1 deg. C.

                                    3 Replies
                                    1. re: nkeane

                                      >It takes 1 Kcal to raise the temp. of a cc of water 1 deg. C.
                                      >
                                      >
                                      ???
                                      1 cal -> raise 1gram = 1cc of water 1deg C.
                                      1Kcal -> raise of 1kg = 1liter = 1000cc of water 1deg C = 1Cal = 1000cal

                                      Beer mug for $50? You could just drink out of a thermos.

                                      1. re: psb

                                        yes, this is what I meant. got Kcal and cal transposed. what we commonly refer to as a calorie is really 1000cal.

                                        1. re: nkeane

                                          Dear Sasha and Flyfish,

                                          Thanks for your information and interest in stone ice cubes. There's some further information I would like to share with you regarding "stone ice cubes".
                                          Soapstone should be used and not marble or granite. They both have a level of porosity and different flavors have been known to stick with them for a while. Soapstone absorbs nothing and won't have any flavor after the cubes are washed. It naturally holds temperature a bit longer because of its density being more than either marble, or granite. Soapstone is also known for its ability to maintain temperature longer than marble or granite. The company I work for sell Soapstone Ice Cubes in 6-packs and 24-packs. They are made in Vermont USA and you can see them at: http://www.temperatureware.com/coolwa... - The last thing is that they actually work if there are basically 2:1 Cubes to liquid, thus the math does work out substantially better when you have twice as much frozen stone mass in relation to un-cooled liquid.
                                          Hope this helps!

                                          Peter Thompson

                                    2. and drinks aren't always watered down by ice - water is an essential ingredient in mixed cocktails. chilling is not the only reason one vigorously shakes or stirs drinks.

                                      1. Just passing along another use for these things........

                                        When we make coffee in the morning my wife drinks it hot, but I (due to the weather the past couple of months) prefer it iced. I mix in some creamer , which partially cools it, then add the stone cubes and put it in the freezer for a while. I then add some ice cubes which don't melt much at all at that point. I COULD use more stone rocks instead....... if I had them. Minimal wait + minimal dilution = happiness on the iced coffee front.

                                        4 Replies
                                        1. re: Midlife

                                          science guy,
                                          What happens to the water when the ice melts. Full glass of ice, full with liquid, it never spills over.

                                          1. re: Tonto

                                            I'm not the science guy, but Google just told me that ice occupies more space than the same amount of water in liquid form.

                                            "In liquid water each molecule is hydrogen bonded to approximately 3.4 other water molecules. In ice each each molecule is hydrogen bonded to 4 other molecules."

                                            Who knew?

                                            1. re: Midlife

                                              you can do an easy experiment. take a glass jar full of water, put the lid on and throw it in the snow. the jar will break when it freezes. but water in a freezer will evaporate if it's in an unsealed container.

                                              1. re: o2cui2i

                                                I get it . Thanks for each of your responses.

                                        2. I tried some in my "Snow-Blitz" snowball maker, and they dented the blades. I will never use them again.

                                          Hunt

                                          2 Replies
                                          1. re: Bill Hunt

                                            ;o]]]]]]]]]]]]]]]]]]]]]]

                                            1. re: Bill Hunt

                                              too funny.

                                              i'm sure they would dent your blender too, but I wonder if glass marbles would work. easy to clean and so pretty.