Everything you wanted to know about powdered sugar

[Carlovski]

Heat death of the universe AND doughnuts in one thread?

Thats why I love eGullet!

[Patrick S]

I for one applaud your willingness to take an active role in the evolution of the cosmos. Now, the average temperature of the universe is only 3K, which is 3 degrees celcius above absolute zero, which is -454 degrees F. So clearly, it would not take too many doughnuts to do the job, you diabolical genius. 

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The average temperature here in Nothern Minnesota is around 39 degrees, (277K), so while powdered sugar donuts are quite popular, (even though they have the inherent disadvantage if being easily lost in the snow), I don't think we have to worry quite yet?

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After performing some extensive thermodynamic calculations on my abacus, I have concluded that the risk of bringing the universe to absolute zero by means of eating powdered sugar doughnuts is somewhat less likely than I originally surmised. However, I would strongly advise against leaving the freezer door open too long.

[srhcb]

I don't know.

I just tried some plain cornstarch, and it doesn't feel, or taste, like much of anything?

SB (will just have to get more donuts tomm .... I mean .... will have to get back to the old laboratory)

Edited April 21, 2006 by srhcb (log)

[highchef]

I think it's too do with the sugar's smoothness...like fine, 600 ct. pima cotton sheets. They feel cool cause they're sooo smooth. Or the page of a fine book. Just open it, and you feel cooler. It's a mind thing, like a yawn is contagious. And it is. It's catching like watching sex in a movie and getting in the mood....same function of the brain.

coolness by association. (hey, isn't that an afternoon special movie??)

[miladyinsanity]

I just tried some plain cornstarch, and it doesn't feel, or taste, like much of anything?

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If it tastes of anything, Steve, you should be throwing the entire box out.

I'd say that it's got to do with the enthalpy of dissolution aka the enthalpy change of solution usually being endothermic. That means the overall enthalpy change is positive, because more energy is taken in than is given out.

If more energy is given out, the enthalpy change is exothermic, and the surrounding temperature will increase--and vice versa.

So if you infer from the fact that icing sugar dissolving on your tongue feels cool, therefore the enthalpy of dissolution of sugar is endothermic.

That does not make a lot of sense even to me, and might be completely wrong.

Edited April 21, 2006 by miladyinsanity (log)

[Patrick S]

I'd say that it's got to do with the enthalpy of dissolution aka the enthalpy change of solution usually being endothermic. That means the overall enthalpy change is positive, because more energy is taken in than is given out.

If more energy is given out, the enthalpy change is exothermic, and the surrounding temperature will increase--and vice versa.

So if you infer from the fact that icing sugar dissolving on your tongue feels cool, therefore the enthalpy of dissolution of sugar is endothermic.

That does not make a lot of sense even to me, and might be completely wrong.

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Cool. That's how ice packs work, right? Ammonium chloride dissolving in water is an endothermic reaction and reduces the temperature of the solution. I guess the only question is, is the dissolution of sucrose in water an endothermic reaction or not, and according to this source, it is indeed:

The dissolution of sugar is an endothermic reaction that provides a slight cooling effect with any sugar when it dissolves. The sensation is more pronounced in certain sugars - dextrose, for example.

[miladyinsanity]

I'd say that it's got to do with the enthalpy of dissolution aka the enthalpy change of solution usually being endothermic. That means the overall enthalpy change is positive, because more energy is taken in than is given out.

If more energy is given out, the enthalpy change is exothermic, and the surrounding temperature will increase--and vice versa.

So if you infer from the fact that icing sugar dissolving on your tongue feels cool, therefore the enthalpy of dissolution of sugar is endothermic.

That does not make a lot of sense even to me, and might be completely wrong.

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Cool. That's how ice packs work, right? Ammonium chloride dissolving in water is an endothermic reaction and reduces the temperature of the solution.

That's the textbook example.

I guess the only question is, is the dissolution of sucrose in water an endothermic reaction or not, and according to this source, it is indeed:

The dissolution of sugar is an endothermic reaction that provides a slight cooling effect with any sugar when it dissolves. The sensation is more pronounced in certain sugars - dextrose, for example.

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Yeah. I couldn't find anything stating that it is, but it should be.

[jsolomon]

Hi, SSB here.

According to these folks, International Critical Tables of Numerical Tables, Physics, Chemistry, and Technology, the heat of solution of sucrose in water is -5.52 kJ/mol. The thing to keep in mind is a kJ is around the same size as a food Calorie, and the negative sign means it absorbs energy.

So, there are two things going on: the chemical act of dissolving sugar in your mouth takes heat energy, and also, the sugar is generally going to be cooler than your tongue, so you will notice that sensation, also.

[Patrick S]

If you want your doughnuts extra cool, SB, you could add some crystalline polyol sweeteners to your powdered sugar doughnuts, since most of them apparently have a much greater negative heat of solution. According to this article, erythritol for instance has a negtive heat of solution (-42.9 cal per gram) that is 10 times greater than that of sucrose (-4.0 cal per gram). In order of descending negative heat of solution, there is xylitol (-36.6 cal per gram), mannitol (-28.9 cal per gram), sorbitol (-26.5 cal per gram), lactitol (-14.9 cal per gram), isomalt (-9.4 cal per gram) and maltitol (-5.5 cal per gram).

[kitchenmage]

As someone who is concerned about global warming, I need some help with the math here. It's a story problem...because we all loved those!

The nearest donuts (or doughnuts? that's a whole other thread, probably already here somewhere) are about 40 miles away, my car gets ~34 mpg, gas is ~3 bucks a gal, it's ~70F outside, and I have PMS-inspired sweet-carb cravings. (TMI? just trying to establish the context)

How many powdered sugar donuts would I have to buy/eat to balance the negative environmental impact of driving 80 miles and using roughly 3 gallons of gas to get them? Are there other powdered sugar coated things that provide a higher level of global cooling per pastry item than donuts?

For bonus points, factor in a stop for espresso on the way and the three miles of bridges where my car will agitate the cooler water and thus drop the temperature in the immediate area.

[jsolomon]

Given that Krispy Kreme (who spell checks corporate names? What a moron...) states the size of their doughnuts are 57 g, and I'm going to assume a safe load mass for your car is about 500 kg, and that you are a 45 kg person, some simple math should do this.

500-45 = 455 kg of doughnuts.

455*1000 = 455000 g of doughnuts

455000/57=7982 individual doughnuts.

7982/13 = 614 Baker's Dozens

So, as many as your car can safely carry.

If we figure each bout is assuaged by one baker's dozen, and you have one bout with each cycle, then you have roughly enough to last you 51 years, or a decade past your menarche... give or take a year or two.

All of that by one trip! Congratulations!

[srhcb]

455000/57=7982 individual doughnuts.

If we figure each bout is assuaged by one baker's dozen, and you have one bout with each cycle, then you have roughly enough to last you 51 years, or a decade past your menarche... give or take a year or two.

All of that by one trip!  Congratulations!

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Luckily, my bakery is on the route between home and work anyway, so I only have to buy a half dozen at a time.

SB (thanks all the scientists who contributed to this thread)

PS: Oddly enough, a little calculating tells me that if I ate 3 of the 7982 donuts each day they would last until almost exactly when I'll turn 65!

[highchef]

I still like mine.

wow, you guys are smart.

here's to egullett...

[kitchenmage]

So, as many as your car can safely carry.

If we figure each bout is assuaged by one baker's dozen, and you have one bout with each cycle, then you have roughly enough to last you 51 years, or a decade past your menarche... give or take a year or two.

All of that by one trip!  Congratulations!

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I am sooooo coming back here when I need justifications for stuff.

[devlin]

I've got an almond cake I'll be mailing and would like to sprinkle some powdered sugar over it but am not sure how wrapping/mailing will affect the look of it. Should I just leave the powdered sugar off and send a packet along with it with instructions? Or is there a way to handle it that won't look godawful?

[baroness]

Package the sugar separately...unless it's the King Arthur "Snow White" type that 'magically' stays white and fresh looking.

[devlin]

Package the sugar separately...unless it's the King Arthur "Snow White" type that 'magically' stays white and fresh looking.

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Fabulous suggestion. I've just ordered some (although not the grout ).

[theabroma]

I second the motion to pack it separately - it will not only get knocked off, but it will become wet and gummy from the moisture from the cake, especially being closed up in a box or tin.

Cheers,

Theabroma

Not to be nosy or anything, but ..... tell us about the cake!

[Dana]

A little note from a Postal Employee: On the outside of the box, print " contains powdered sugar." On the tiny chance that your package would leak, this will save untold problems.

[devlin]

Thanks for the comments.

Not to be nosy or anything, but ..... tell us about the cake!

The cake is a simple, nearly flourless almond cake from Alice Medrich's Pure Dessert. It offers some separate options for fancying it up a bit (baking with chopped almonds scattered on the bottom and the sides of the pan while baking, and serving with a variety of fruits or fruit purees, for example). Honestly, though, I love it plain, or with just a fine bit of sifted powdered sugar. Since I'm baking small ones to ship to friends and family for Christmas (in addition to some cookies and another small cake), I thought it would be nice to make them a little prettier by sifting the sugar on before I package it.

[alexthecook]

As I was trying to make a glaze recently, I mixed some powdered sugar with some water.

I tasted it and was quite disconcerted to find a definite "soapy" taste. My girlfriend detected it clearly also.

We tasted my mother in law's powedred sugar (also with water), and again found that soapy taste!

What's wrong? Is it supposed to have this flavour? I'd never noticed it before..

Could it be that it's too old (at both places)?

Help! I want to make a glaze (for eclairs... no time for fondant)!

[Qwerty]

What kind of water did you use? Maybe try bottled water...?

Was there residue in the mixing bowl?

[gfron1]

having just had a similar thing happen I would be willing to bet its the bowl not being fully rinsed - either with soap residue or with cilantro residue.

[AmritaBala]

I had the same problem once. Did you store your icing sugar properly? Was it exposed to air? I realized that mine wasnt sealed properly so it absorbed "odours".

[lennyk]

try a different brand, some of the corn starch they put in powdered/icing sugar may have the off taste or texture