Steam or Water?

[tim]

So, Sprout - is that why steam (which is hotter than water) takes longer to blanch than water??
Much better though!!

[tim]

[tim]

SS - your PM box is full, so may I ask for your judgement here??

[Curryandchips]

If I can interject Tim, you are correct in your interpretation, yes the steam in contact with the vegetables delivers less energy. In terms of temperature, it will actually be at the same temperature as the water, ie 100C unless it is receiving extra heat after it has been turned to steam, which will not happen if it has been produced by normal boiling.

[tim]

Oooh - thought that steam was always hotter than water. Not a clue why!

But thanks!

[Curryandchips]

In a way, you are possibly right, but it depends upon terminology, clarity is essential here. If we talk about the amount of energy contained in a quantity of water, then as steam it contains five times MORE energy than is needed to heat the water from freezing point up to boiling point. This is just to turn it into steam, without any increase in temperature, ie it is still at 100C. So this requires an interpretation of the meaning 'hotter', does it mean more energy, or a higher temperature.

To me, this is an excellent argument for paying attention to science classes at school !

Apologies if anyone glazed over at this point, teaching is not a strong point ...

[tim]

Thanks again!!

[supersprout]

he he tim, just back home, since you ask will scratch head and think about this one, may not have much to add to curry but you never know :o ;D

[Curryandchips]

Well you are so much more prosaic supersprout ...  :)

[supersprout]

the steam in contact with the vegetables delivers less energy. In terms of temperature, it will actually be at the same temperature as the water, ie 100C

Two thoughts to add, tim ;D

First, it might take longer to get your steamer to produce steam for cooking than it does just to bung the veg in hot water ie to get it 'up to steam'. This is due to the extra energy needed to turn water to steam - it might just take longer to produce. A friend of mine had an early steam oven and it took forever to get to 'steam' before you started cooking.

Second, even though water and steam will both be at 100 degrees (so the temperature is the same) the convective heating efficiency of air is less than that of water at the same temperature - which is demonstrated by putting your hand in a 100 degree oven, as opposed to plunging it into a pan of 100 degree water. So heat transfer should, in theory, be slower with steam.

Just so you know I heed the Wisdom of Tim, I did potatoes yesterday in the veg steaming water and put it in this morning's bread, and the taste is excellent. And I have ordered the book you recommended so it better be good he he ;D ;D

[tim]

Worth waiting for!!

[tim]

This is the sort of thing (steaming tips) that gets us off track?

And yet we know that blanching times in steam are always 1 min or so longer.

http://www.dole.com/Recipes/Rec_Ed_020-Steamed.jsp

[supersprout]

Curse of the Copywriter tim? ::) 8) altho' we all have to earn our crust.
A copywriter friend rang me one memorable summer afternoon to check her sanity. She was writing a housewares catalogue, and had to find something interesting to say about a fold-out muslin umbrella (you know, that kept flies off food). Between sobs, she managed to blurt 'I just wrote Keep the Bees off the Cheese!'

[Hyacinth]

Keep the Bees off the Cheese[/i]!'

;D ;D ;D ;D ;D ;D
(I've a friend who writes copy like that 8))

[Debs]

...or the flies off the cake  ;D