Pre-heated ovens

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ChrisGreaves
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Pre-heated ovens

Post by ChrisGreaves »

What, as we say, is with it with cooking instructions that say “ ... into an oven pre-heated to 350 degrees ...”.

I can understand a need for this for some dish that needs to be flash-cooked, brought quickly to a high temperature. Yorkshire Pudding (as it is cooked anywhere except North America) comes to mind.

But here are recipes for Meat Loaf, fer heaven’s sake, which ask me to “Bake in an oven pre-heated to 350 degrees ...”. Why?
It seems to me that Meat Loaf (or any other meat-based casserole or similar dish) will cook more evenly if the dish is placed into an oven and the heat then turned on.

And while I can see a pre-heated oven as being a base-mark for gingersnap cookies that we want to bake for exactly 12m 35s to make sure that they come out not-too-crisp and not-too-soggy (as if!), it makes no sense to me with Meat Loaf when the quantity I press into the baking tin affects the cooking time anyway, preheated or not.

I won’t be returning to the Meat Loaf oven in the kitchen until I have finished this chapter, done this crossword, or debugged this little VBA procedure, and the Meat Loaf doesn't seem to mind ...
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HansV
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Re: Pre-heated ovens

Post by HansV »

For a casserole, which will be in the oven for quite a while, it probably doesn't matter much.

Pastry is different - if you heat it slowly, the butter will run out...
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Re: Pre-heated ovens

Post by BobH »

I've read (old-timer's disease prevents recalling the source) that ovens are preheated because, as the food is cooking, some bacteria will multiply rapidly and taint the dish. Not all bacteria are killed at high temps, though most are. Why risk it when pre-heating the oven is so easily accomplished?
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ChrisGreaves
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Re: Pre-heated ovens

Post by ChrisGreaves »

HansV wrote:..., it probably doesn't matter much.
My thoughts exactly.
I suspect that nowadays most people have hard-wired the "pre-heated" to the front of "oven" and write "pre-heated oven" without thinking.
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Re: Pre-heated ovens

Post by HansV »

There is BobH's caution to take into account. But that also depends on what you're preparing of course.
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DaveA
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Re: Pre-heated ovens

Post by DaveA »

I just have the habit of turning on the oven before I start putting the meatloof together. It takes time to find all of the items and then measure them out and mix them up. By then the oven is nice and toasty and ready for the meatloaf and potatoes to be baked.
I am so far behind, I think I am First :evilgrin:
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ChrisGreaves
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Re: Pre-heated ovens

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BobH wrote:I've read (old-timer's disease prevents recalling the source) that ovens are preheated because, as the food is cooking, some bacteria will multiply rapidly and taint the dish. Not all bacteria are killed at high temps, though most are. Why risk it when pre-heating the oven is so easily accomplished?
Hmmm. Hi Old-Timer (GRIN!)
I still can't see for Meat-Loaf dishes and the like it being a serious problem.
I take the ground meat out of the (now functioning again!) fridge, mix in the "stuff", pop it in the oven, turn on the oven, and an hour or so later ...
I believe that bacteria love feasting on raw meat, but I believe too that there is a window of opportunity, and providing I'm not leaving the meat exposed at room temperature for hours on end, the risk is minimal compared to all the other risks (bacteria on the fridge door handle, on the counter, in cuts in the chopping board etc.)

I also have a feeling that our bodies have evolved to deal pretty well with (especially) meat-based bacteria.
I figure we are much better off than cavemen who cooked and digested a mastodon over several days. Their bacterial risk must have been phenomenal!
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Re: Pre-heated ovens

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HansV wrote:There is BobH's caution to take into account. But that also depends on what you're preparing of course.
Well, yes, for sure, but my initial thoughts were "solid" dishes that were simmered for hours on end, or at least, half-hours on end.

Eggs come to mind, especially raw eggs.

But the first time my mum tried to bake meringues on the wood-fired stove in Southern Cross (W.A. desert) she found the oven was too hot; it was mid-summer after all, so she left the tray of meringue cakes on the kitchen table while the oven cooled down a bit.
By the time the oven had cooled (heating the kitchen of course!), mum found the meringues were cooked.
She never again cooked meringues in the oven after that; just mixed the egg white and sugar, dabbed them out, and left them to cook on the kitchen table.

And I love meringues.
And I'm still alive today!
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Re: Pre-heated ovens

Post by Rudi »

I don't cook from recipes that often at all, but my first thought after reading this thread was....go back to basics; and the most basic cooking is by open flame...and that I believe is ALWAYS pre-heated.
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Re: Pre-heated ovens

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DaveA wrote:I just have the habit of turning on the oven before I start putting the meatloof together....
True Confession: Me too! Also for cookies and the like.
Especially on the 37th consecutive day of below 0c weather.

I was really just musing over the number of recipes that say "Pre-heated oven" as distinct from "oven".
I'm with you on the getting-it-ready idea.

For that reason I also am in the habit of reading the recipe all the way through and getting ALL the containers of ingredients on the counter BEFORE I break the first egg.
Y'all know why that is!
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Re: Pre-heated ovens

Post by DaveA »

Their bacterial risk must have been phenomenal!
and their bodies were more adapted with better natural protection than what we have today.
I think that we have lost more natural protection than we have gained on using the man made science.
I am so far behind, I think I am First :evilgrin:
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Re: Pre-heated ovens

Post by ChrisGreaves »

Rudi wrote:...the most basic cooking is by open flame....
Well, we don't all live in South Africa :laugh: :rofl: :innocent: :flee: :clapping: :evilgrin: :thumbup: :alien: :cheers: :chocciebar:
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ChrisGreaves
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Re: Pre-heated ovens

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DaveA wrote:I think that we have lost more natural protection than we have gained on using the man made science.
Quite possibly.
Leaving aside these resistant bacteria/viruses that, it is said, mutate faster than the drugs (antibiotics) can keep up with them, I often think that people who spend half their life antiseptic-ing their hands are denying their body the ability to acclimatize to bacteria and mount natural defenses.
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Re: Pre-heated ovens

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ChrisGreaves wrote:
Rudi wrote:...the most basic cooking is by open flame....
Well, we don't all live in South Africa :laugh: :rofl: :innocent: :flee: :clapping: :evilgrin: :thumbup: :alien: :cheers: :chocciebar:
Is this what's known as "flaming"?
Or if Rudi gets upset will it be "a flaming row?" :innocent:
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Re: Pre-heated ovens

Post by Rudi »

I hardly saw that row of smiley's... I skipped right over to the last one. (I luv choccie!!)

Well, now we have open flames :fire: and open beaches :moon: ...
I'll have to track down Ruby and have a braai on Mpenjati Beach soon...
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Re: Pre-heated ovens

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Rudi wrote: (I luv choccie!!).
Well if you look closely at the photo I just posted you'll see "Bulk Barn" off to the right of the photo on Carlton Street.
They have lots of bins of Chocolate.
Piles of the stuff!
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Re: Pre-heated ovens

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ChrisGreaves wrote:Piles of the stuff!
Thanks for the tip...just hope there are no dogs close by!
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Re: Pre-heated ovens

Post by Cellmate »

I realize this thread is nearly a year old, but I felt like weighing in.

I think the recipes call for a preheated oven so the cooking times will be at least fairly accurate over the
wide variety of ovens used over the world.

All ovens take different amounts of time to come up to temp. If your dish is supposed to be done in 35 mins at 350
you need to start from a 350 degree oven.

If you put your dish in a cold oven and leave it in for 35 mins, it won't be done properly.

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Re: Pre-heated ovens

Post by RonH »

Have you ever opened the door of an oven pre-heated to 350C. Your skin will be super smooth :grin:
But maybe you mean 350F ...
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Re: Pre-heated ovens

Post by BobH »

A rule of thumb in professional kitchens - and good non-professional ones - is ". . . to be safe you should go from 40 degrees to 140 degrees in a 4 hour window to ensure that there isn't bacteria growth in the meat."

I think this - and the vast variance in types and capabilities of ovens, and the avarice pf PI lawyers - is behind the pre-heat instructions.
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