how do oven temperatures actually work?

[kazeya]

hi all! i just purchased a bosch oven recently..and was noticing the temperature

on preheating period..the oven temperature reaches the desired temperature and stays there for long periods and remains constant..however as i place any item into the oven for baking..the temperature drops by 20oC..does this happen for all ovens? is this how the temperature works? i understand everytime u open the oven door the temperature drops however mine just stays at minus 20oC of the preheated value..is this because the baked item is absorbing the heat as it bakes? O_O

please advice

PS : my oven heating setting is set on top and bottom heat element..without the turbofan on..

 

[kyheirloomer]

How long does it stay at the dropped temperature?

The oven thermostat works on a mini/max basis. That is, once it comes to temp, the heat turns off. The internal temperature then begins to drop. At a certain point---which varies by manufacturer, and can be as much as 25 degrees F---the heat gets turned back on again. The oven will continue cycling like that as long as it's on.

20C however seems like an inordinate drop to me. That would be what? About 45F?

I'd have the oven checked out, as there's probably a malfunction.

 

[kazeya]

well during the preheating stage it doesn drop at all..instead it remains at the required temperature

however the moment i place my item in the oven for baking..it starts to drop but remains constant after that (at the dropped temperature)..im wondering whether is it normal for temperatures to drop and remain like that while baking something inside

 

[kyheirloomer]

From what you describe, there is something wrong with the kick-back-on setting on your thermostat.

Get it checked out while it's still on warranty.

 

[homemadecook]

 Please look at this data. Hope it helps.

 

[gerdosh]

Oven temperature should remain constant in a good oven. Yes, it may drop some when adding the dish but it should quickly come up to the dialed temp. Something is not right with your.

 

[warba]

Kazeya, what instrument are you using to determine what the actual temperature of the oven is? Is this a separate thermometer placed inside the oven, or one in the door, or are you judging the "consistency" (or lack thereof) by a thermostat/indicator on the oven itself?

From what you describe, if your temp readings are accurate, then it sounds like the oven needs to be adjusted to cycle faster with less of a temp drop.

The reason I ask is that digital read-outs on some ovens will lie to you and make it look like temps are consistent when they are not.
I have seen many spring-type manual oven thermometers be inaccurate or take so long to register temperature changes that you really are not getting a true picture of actual oven temp.

I bought a temperature controller from Auber instruments auberins.com to control a smoker and it has a very sensitive probe that indicates temperature to the 1/2 of a degree and reads almost instantly. It was an eye-opener to see what the real temperature of ovens was, and what the dwell temp was before oven's own thermostat kicked in. An old oven would drop over 20 degrees before turning the element back on. I have a new convection oven and it has 2 settings that determine how cool the oven has to get before the heat is turned back on. The "standard" one can drop 5-10 degrees before cycling back on; fine for roasts, etc. with the other setting basically cycling the heat on and off every 30 seconds or so and keeps the temp within about 5 degrees (also if oven door is opened it cycles on almost instantly).

 

[amazingrace]

Your thermostat measures the ambient temperature of the air inside the oven and the "ready" beep sounds when the air has reached the set temp.  However until the walls, floor and ceiling of the oven have been heated through,  opening the door for any reason is not advised.  Listen for the beep,  then set a timer for an additional 10 to 15 minutes before proceeding with your baking. 

 

[kyheirloomer]

Good point, Grace. And even more important if you use a baking stone of any kind.

 

[amazingrace]

I have a nice rectangular baking stone that is never removed from the oven.  I find that once the oven is completely preheated,  the stone helps to maintain an equal temperature throughout the baking time. 

 

[kyheirloomer]

Absolutely, Grace. I have a similar set up. It certainly takes much longer to heat up the oven properly. But once there, the stone helps regulate and stabalize the temperature.

The key is patience. With my oven, and depending on desired temperature, it takes 40 minutes to an hour to reach the temp I want. But once there the oven does not cycle near as often as without the stone.

 

[warba]

Normally in a home cooking environment you don't notice it, but your oven will lie to you; the temperature on the nice digital display is not the temperature inside of your oven. Once the temperature rises to what you have set it to, the indicator will generally stay on the set value regardless of the actual inside oven temp. Prove this by pre-heating your oven until it "beeps" or indicates it is hot.

Now open the oven door and leave it open. In most every oven the indicator will not change, even though the inside temp is most definitely falling. You will hear the oven cycle on, but the temp indicated won't change.

The original question by Kayeza was asking about temp drop and you are really at the mercy of your oven setting between when the thermostat senses a drop and when it actually turns on the element/burner. This is often adjustable (though by a service person generally) on higher-end ovens and commercial units; unsure but maybe not on cheaper home units.

A consequence to a poorly manufactured or calibrated oven is that it works the opposite way also.. once the thermostat registers enough of a temp drop to cycle on the element, it will heat the oven to a temperature that may be higher than what you have set on the indicator. Again, the display (if digital) will lie to you and show the "350" you set the oven to, even though it may be set to not turn off the element until 10-15 degrees higher. You see this with really cheap home ovens that always seem to scorch food.

As others have suggested, getting a large pizza stone in the oven will help to smooth out the highs and lows of a poorly calibrated oven. Another trick if you know it will take some time to "load" your oven is to preheat it to 50 degrees higher than you need. Once the oven "beeps", open the door and load the oven, then close the door and reduce the temp to where it should be. The drop in temp of the oven then will still leave it near the ideal temp you are looking for. Works great for getting a good "oven spring" for making bread at home since a good hot oven at beginning of cooking is important to a good rise, and also for sensitive bakery items like pastry, cookies, etc..

I'm a bit passionate about this subject because I used to have a crappy oven in university and would put in a sheet pan of pastry to cookies and the oven would cycle on and heat way beyond what it was set to, scortching the bottoms of the product. Pre-heating to 40-50F higher than the required setting worked a charm since I could get the goods into the oven and close the door, then turn the oven down to 350 and the element wouldn't cycle on and blacken the bottom of the pastries.

 

[marcuschua]

Hello guys,

Im new to this forum and found this old thread while looking for the solution to the same problem. I bake in my new oven for the first time, it's a Tefal Uno XL OTC oven. I preheated to 170C and after i put my cake in, it dropped to 140C and stayed there throughout the baking time. The top of chiffon cake cracked probably due to it being near to the top heating element, i tried covered with foil but it was too late.

OP, how did you solve your oven problem in the end? I would be glad if you could share your experience

P/s: i know this is an old thread but i felt that creating another thread of the same problem isnt right.

Thanks guys!