302440 Tue Aug 02 20:41:20 -0700 2005 20 29 Not About Food 0 1693195 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..... Tue Aug 02 20:41:20 -0700 2005 0 Sasha 1 1693214 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. Wed Aug 03 09:57:29 -0700 2005 1693195 0 FlyFish 2 1693218 you are my Chowhound Science God. Thank you for saving my some $$$$$. I will invest in some more ice cube trays. Wed Aug 03 10:53:19 -0700 2005 1693214 0 Sasha 2 1693219 AWESOME freaking post! Wed Aug 03 11:07:47 -0700 2005 1693214 0 Just passing by 2 1693223 So, does hot water freeze faster than cold water? Wed Aug 03 11:18:16 -0700 2005 1693214 0 rudeboy 3 1693226 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. Wed Aug 03 13:28:49 -0700 2005 1693223 0 Jess 2 1693224 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. Wed Aug 03 12:04:06 -0700 2005 1693214 0 dude 2 1693236 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. Wed Aug 03 16:59:40 -0700 2005 1693214 0 Tugboat 3 1693599 Maybe you could experiment with some regular rocks. They're plentiful and free. On the other hand, the hell with it. Tue Aug 09 22:55:44 -0700 2005 1693236 0 flavrmeistr 2 1693240 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 Wed Aug 03 17:36:55 -0700 2005 1693214 0 Roy 3 1693241 try using distilled water... I think it is the calcium, etc. in tap water that makes the cubes cloudy. Wed Aug 03 18:23:37 -0700 2005 1693240 0 withalonge 3 1693246 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. Wed Aug 03 19:19:09 -0700 2005 1693240 0 DanaB 4 1693258 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. Wed Aug 03 21:46:53 -0700 2005 1693246 0 FlyFish 2 4600241 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. Wed Apr 15 23:16:42 -0700 2009 1693214 262418 bugmenot 3 4602099 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. Thu Apr 16 13:13:02 -0700 2009 4600241 27275 ML8000 2 4601987 I get it, but I have to tell you that my eyes began to cross uncontrollably about half-way through. Thu Apr 16 12:43:15 -0700 2009 1693214 11405 Midlife 1 4600865 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! Thu Apr 16 07:56:10 -0700 2009 1693195 12120 julesrules 1 4602023 Wouldn't those stones break your glasses? Why not just buy some plastic ice cubes? Thu Apr 16 12:53:28 -0700 2009 1693195 12082 PeterL 1 4602643 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. Thu Apr 16 16:24:41 -0700 2009 1693195 39457 nkeane 2 4610369 >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. Sun Apr 19 21:54:02 -0700 2009 4602643 16770 psb 3 4610388 yes, this is what I meant. got Kcal and cal transposed. what we commonly refer to as a calorie is really 1000cal. Sun Apr 19 22:03:15 -0700 2009 4610369 39457 nkeane