Steamer or microwave?

[dcarch]

43 minutes ago, Porthos said:

When water has turned to steam has a high level of thermal energy in each molecular. -------

 

 

First, I am assuming you are not talking about visible "steam", which is just tiny water droplets. Actual steam (water vapor) is not visible.

But there are not many molecule in one cubic foot of steam, (thermal mass)  compared to one cubic foot of boiling water.

Therefore, you have about 1,120 BTUs in one cubic foot of boiling water and only 240 BTUs in one cubic foot of steam.

 

dcarch

 

 

 

Edited September 16, 2016 by dcarch (log)

[Smithy]

There is also the latent heat of condensation to be considered when comparing steam to boiling water.  It's a factor in burns.  Would it not also be a factor in steaming vs. boiling potatoes?

[JoNorvelleWalker]

14 minutes ago, Smithy said:

There is also the latent heat of condensation to be considered when comparing steam to boiling water.  It's a factor in burns.  Would it not also be a factor in steaming vs. boiling potatoes?

 

Without doing the math myself, I believe @dcarch has taken this into account.  As I recall MC asserts boing water transfers heat more effectively to food than steam.  But I don't have MC in front of me to check.

[Thanks for the Crepes]

7 hours ago, huiray said:

I dislike microwaved broccoli. To me, it tends to stink. It also lacks the "mouth-feel" that blanching it in oiled simmering water gives it.

 

I like a lot of vegetables microwaved in glass covered with glass. Corn and sweet potatoes are almost always done this way. I also will nuke chopped carrot I'm going to add to fried rice or another stir fry for a few minutes before adding it, as I like it softer than it can get in a stir fry without scorching on its own or overcooking the other components.

 

I've tried broccoli a few times too, and expected a good result. What I actually got was a little scorching on the tips of some florets, which seemed to transfer an acrid, bitter flavor throughout the entire dish. As huiray says, it has a bad smell and taste at least to me. Now I do broccoli in ample boiling water for about four minutes, on the advice of Marcella Hazan, and I much prefer it that way.

 

I love some roasted cauliflower, and other veggies, but my bad experiences with nuked broccoli have prevented me from trying to roast it.

[dcarch]

On 9/16/2016 at 0:44 AM, Smithy said:

There is also the latent heat of condensation to be considered when comparing steam to boiling water.  It's a factor in burns.  Would it not also be a factor in steaming vs. boiling potatoes?

 

By definition, I don't think steam can ever be hotter than boiling water, 212F (100 C) unless it's under pressure. The moment steam enters air which is colder than 212F, it immediately condenses and becomes visible water (so called steam), at that point, latent heat of water vapor (steam) is no long there.

Pressure cooker steaming is different.

 

dcarch

Edited September 20, 2016 by dcarch (log)

[btbyrd]

Modernist Cuisine reports that steaming is actually slower than boiling for many foods (Vol 2, p. 70-73). They constructed an experiment where a thermocouple was placed at the center of two identical aluminum cylinders, which were then "cooked" in either boiling water or steam. Boiling was consistently faster than steaming. The blog Genuine Ideas performed a similar test using carrots and found that boiled and steamed carrots cooked at the exact same rate. Whatever the case, steaming isn't faster.

 

Steaming can be "faster" than boiling in contexts where you're cooking a lot of product. From start to finish, it's probably faster to steam 10lbs of potatoes than to boil them, given how much water boiling would require (and that you may have to cook them in batches). In any case, I pressure cook large amounts of potatoes. 

[Cyberider]

Very interesting on steam vs boiling.

 

As for broccoli, I microwave it frequently.  I first microwave the stems and then put in the florets and finish them all off together.  Apparently, there are several varieties of broccoli and it seems to me that the ones with the coarser florets have a stronger, more bitter, taste and odor.  For that reason, I try to buy only the fine-floretted varieties.

Edited September 16, 2016 by Cyberider (log)

[JoNorvelleWalker]

I pressure cook small amounts of potatoes.

 

[VioletGibson]

I don't cook in our micro. I use it to reheat leftovers. I use my steamer on a daily basis. ! It is so easy to use, not to mention healthier.

 

[dcarch]

2 hours ago, VioletGibson said:

I don't cook in our micro. I use it to reheat leftovers. I use my steamer on a daily basis. ! It is so easy to use, not to mention healthier.

 

 

What makes it healthier?

 

dcarch

[liuzhou]

2 hours ago, VioletGibson said:

I don't cook in our micro. I use it to reheat leftovers. I use my steamer on a daily basis. ! It is so easy to use, not to mention healthier.

 

 

Healthier than what?

[csingley]

4 hours ago, VioletGibson said:

I don't cook in our micro. I use it to reheat leftovers. I use my steamer on a daily basis. ! It is so easy to use, not to mention healthier.

 

You should try steaming your leftovers, it works better than the microwave for the most part.  And as noted here, some foods (notably corn) work really well in the microwave - couldn't be easier.

 

"Healthier"?  This ought to be good. I'mma go pop some popcorn - in my microwave, of course.

 

On 9/16/2016 at 7:41 AM, dcarch said:

 

By definition, I don't think steam can ever be hotter than boiling water, 212F (100 C) unless it's under pressure.

 

 

Superheated steam definitely exists; it's how steam locomotives worked.  Nasty stuff.  You're talking about "saturated steam" - wet steam not dry - both liquid and gas phases in thermodynamic equilibrium.  Happily, saturated steam is all we get in the kitchen, but as long as we're defining.

 

On 9/16/2016 at 7:41 AM, dcarch said:

The moment steam enters air which is colder than 212F, it immediately condenses and becomes visible water (so called steam), at that point, latent heat of water vapor (steam) is no long there.

 

I think we can assume that ambient temp in a steamer is the BP of water, so condensation rather than collision is going to be a major mode of heat transfer to the potatoes, eh.

[csingley]

On 9/13/2016 at 5:33 AM, liuzhou said:

 

I've mentioned this many times, but in over twenty years in China, I've never, ever seen anyone steam vegetables. Fish, yes. Eggs. Pork. Bread and buns, of course. But never vegetables. They are always stir-fried (in lard (pork fat) or oil) or used in soups/hot pots..

 

As I've also said before many times, I've never seen a bamboo steamer in a domestic kitchen in China. None of my friends have them and I wouldn't know where to buy one if I had to. There is a street full of kitchen supply shops only ten minutes walk away. They don't have them. They are only used in dim sum restaurants and dumpling/steamed bread shops, although even there they are dying. The metal ones are deemed to be more hygienic.

 

 

 

True dat, the Chinese don't steam vegetables.  I'm pretty sure the jielan in oyster sauce served with dim sum is boiled.

 

I was back in Taipei in August and had a hard time sourcing bamboo steamers.  I ended up having to trek down to the old market down behind the train station - one of the main drags for restaurant supply.  There I was able to find a couple shops that specialized in bamboo goods for food service, and hooking up with some real beauties - 14" diameter, 1/2" thick walls, thick wire handles covered with plastic tubing.  Care of these things is more of a PITA than metal racks - if they've been disused, you have to soak them before use, then hang them up to dry afterward, whereas you can just blast metal steamers in a commercial dishwasher no problem.

[dcarch]

20 minutes ago, csingley said:

Superheated steam definitely exists; it's how steam locomotives worked.  Nasty stuff.  You're talking about "saturated steam" - wet steam not dry - both liquid and gas phases in thermodynamic equilibrium.  Happily, saturated steam is all we get in the kitchen, but as long as we're defining.

--------------------

What I said: under normal pressure (normal kitchen environment).

Steam can be 1,000F or higher under pressure. 

From WIKI:

" Superheated steam and liquid water cannot coexist under thermodynamic equilibrium, as any additional heat simply evaporates more water and the steam will become saturated steam. However this restriction may be violated temporarily in dynamic (non-equilibrium) situations. To produce superheated steam in a power plant or for processes (such as drying paper) the saturated steam drawn from a boiler is passed through a separate heating device (a superheater) which transfers additional heat to the steam by contact or by radiation. "

 

I think we can assume that ambient temp in a steamer is the BP of water, so condensation rather than collision is going to be a major mode of heat transfer to the potatoes, eh.

All thermal dynamic actions are molecular collisions. Not sure what you are trying to say.

 

dcarch

 

Edited September 20, 2016 by dcarch (log)

[csingley]

 

I'm just being pedantic; you omitted the word "saturated" in your claim that steam by definition is pinned at the boiling point.

 

5 minutes ago, dcarch said:

All thermal dynamic actions are molecular collisions.

 

Nah dude, surface tension is, like, electromagnetic and stuff.  delta H_vap is potential energy converted to kinetic, not a transfer of kinetic energy via collision a la Boltzmann.

 

NERD FIGHT!!

[naguere]

My top tip for the best veg and retaining nutrients is to go with the Microwave.

 

Use frozen veg and here is the secret, use only a tablespoon of water in a proper micro container.

 

I read of tests done on Broccoli and nine out of ten preferred the frozen cooked this way than doing fresh any way you like.

 

[dcarch]

27 minutes ago, csingley said:

 

I'm just being pedantic; --------

I agree.

 

Nah dude, surface tension is, like, electromagnetic and stuff.  delta H_vap is potential energy converted to kinetic, not a transfer of kinetic energy via collision a la Boltzmann.

NERD FIGHT!!

Not relevant.

" A rise in the temperature of matter makes the particles vibrate faster. Thermal energy is what we call energy that comes from the temperature of matter. The hotter the substance, the more its molecules vibrate, and therefore the higher its thermal energy. "

Back to steam vs microwave. Steam temperature is 212F, it can overcook some food if you are reheating. Microwave (inverter type microwaving) can give you better reheat control. 

 

dcarch

 

Edited September 20, 2016 by dcarch (log)

[csingley]

32 minutes ago, dcarch said:

A rise in the temperature of matter makes the particles vibrate faster. Thermal energy is what we call energy that comes from the temperature of matter. The hotter the substance, the more its molecules vibrate, and therefore the higher its thermal energy. "

 

What you're missing is that potential energy (like the heat of vaporization stored in steam) is not thermal energy.   When you cook potatoes in a steamer, the steam condenses on the potatoes and transfers the heat of vaporization to them.  This is a separate energy transfer, in addition to the energy the fast-moving steam imparts by banging into the cooler potatoes because it's at a higher temp.

 

Heat transfer via condensation is going to excite collisions in the food when you're cooking, but liberating heat of vaporization does not necessarily involve collision at all.  If you put a blob of steam into outer space, it would lose the heat via radiation instead.  It isn't useful to think of condensation as being some sort of collision effect, any more than burning is usefully understood as collision.  You need to know how much EM potential energy is stored, and no matter how much calculus you throw at it, you can't derive that from treating the molecules as a vast collection of ping-pong balls operating under Newton's laws.  This is not explained by classical statistical mechanics.  There's more to thermodynamics than just hot things banging into cold things.

 

Here's a wiki article on latent heat.

 

Quote

Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process.

 

Constant temperature => nonthermal energy transfer.  Not collision.

Edited September 20, 2016 by csingley (log)

[dcarch]

20 minutes ago, csingley said:

 

What you're missing is that potential energy (like the heat of vaporization stored in steam) is not thermal energy.   When you cook potatoes in a steamer, the steam condenses on the potatoes and transfers the heat of vaporization to them.  This is a separate energy transfer, in addition to the energy the fast-moving steam imparts by banging into the cooler potatoes because it's at a higher temp.

 

Heat transfer via condensation is going to excite collisions in the food when you're cooking, but liberating heat of vaporization does not necessarily involve collision at all.  If you put a blob of steam into outer space, it would lose the heat via radiation instead.  It isn't useful to think of condensation as being some sort of collision effect, any more than burning is usefully understood as collision.  You need to know how much EM potential energy is stored, and no matter how much calculus you throw at it, you can't derive that from treating the molecules as a vast collection of ping-pong balls operating under Newton's laws.  This is not explained by classical statistical mechanics.  There's more to thermodynamics than just hot things banging into cold things.

Off topic.

 

dcarch

[csingley]

Blew past "off topic" a couple signposts ago!  Just relevant to the reason why steam cooks roughly as fast as boiling in water, despite the lower thermal mass and identical temperature (which you pointed out).  Latent heat of condensation is pretty large, and not comprehended in thermal mass or delta temp.  That's the term that balances the books.

 

But steaming vegetables still gets the thumbs down from me.  Boo lite cuisine.  I'll go with either "(b) microwave", or "(c) none of the above".

[dcarch]

5 hours ago, csingley said:

Blew past "off topic" a couple signposts ago!  Just relevant to the reason why steam cooks roughly as fast as boiling in water, despite the lower thermal mass and identical temperature (which you pointed out).  Latent heat of condensation is pretty large, and not comprehended in thermal mass or delta temp.  That's the term that balances the books.

 

-----------------

 

Sorry, you are wrong. As also proven by Modernist Cuisine. 

 

dcarch

 

Edited September 20, 2016 by dcarch (log)

[csingley]

8 hours ago, dcarch said:

 

Sorry, you are wrong. As also proven by Modernist Cuisine.

 

 

Huh.  "Modernist Cuisine" 2-71: "Steam... can transfer huge amounts of energy to food because it contains latent heat, which it deposits onto the food surface when it condenses".

 

A couple pages later, there's a nice graph showing their experimental data, with steam cooking lagging just a little bit behind boiling... far closer than can be explained by the dramatic differences in density between liquid & gas phases.

 

I guess Myrvhold's wrong too?

 

Look, being right or wrong isn't the point... it's the WHY that's interesting to me.  You really threw me talking about latent heat of condensation; I thought I was among thermo nerds, but if not I'm being quite a bore.  I apologize for hijacking the thread.  Back to cooking.

[dcarch]

csingley

"------- with steam cooking lagging just a little bit behind boiling... far closer than can be explained by the dramatic differences in density between liquid & gas phases.

I guess Myrvhold's wrong too?---"

 

I must have missed something. If so I apologize. All along, I thought you are saying that steam cooks faster, now you are saying steam cooking lagging behind boiling. I am confused.

 

And BTW, no need to explain latent heat. My profession requires me to have a good understanding of the subject. 

 

I agree, back to cooking.

Those of you who have not had good experience with microwave cooking, should look into "inverter microwave ovens". I don't know why they didn't use another terminology. Inverter is used for another electronic device.

 

dcarch

 

[Porthos]

If my understanding of why I believe steam is better is wrong, I can live with that. My preference is to steam. Your mileage may vary.

 

My information was based upon the 2 episodes on Good Eats looking at water.

Edited September 21, 2016 by Porthos (log)