Oven Temperatures

The Germans and Austrians also seem to have a different system where "Stufe 4" is roughly gas mark 7. As an Englishman in Austria with an old oven in my apartment, this confuses me no end.

Does anyone here know the history of Gas Marks ? I've seen those used in french cooking books (and was uterly confused). What I don't understand is how good it can be to control the oven temperature ? Doesn't the oven heat capacity (btu/hr?) change from one model to another ?

I found a website at http://www.xs4all.nl/~margjos/oven.htm that had some Stufe (degree in german?) equivalences and added them to the Gas Mark table.


Gas Marks, as it is used today, is a term for temperature and not for energy (btu) or power (btu/hr). The ovens are presumably adjusted so that enough energy is produced by the burners to maintain a relatively standardized Gas Mark. Although, the etymology of the term is unclear (I believe the Oxford English Dictionary just started another search for early references of the term), it probably started out as an arbitrary unit of burned gas and then evolved into a (more or less) specific temperature, but that's just my guess. Any language experts out there who can provide us the origins of this term?

Thank you for the oven conversions! If you'd tackle the similar kitchen conversions - esp grams/cups which I KNOW aren't technically convertible but yet need to be for cooking practices - it'd be much appreciated. I've searched all over for an easy reference with no luck. Alanna

Gas fuelled ovens would have been the first step in the progression from cooking on a wood or coal heated range.

As cooks would have previously controlled heat by burning more or less fuel, they would not expect a thermostatically controlled oven - indeed, would have had no concept of it. Even today, the famous AGA ranges have no way of controlling the temperature by use of a thermostat.

Only when thermostatically controlled electric ovens became available would it have been necessary for gas oven manufacturers to try to produce a matching feature.

Thanks for the verbal conversions. I'm never sure how to treat those

DrObvious
www.zigguratofdoom.com

The temperature on the dial and the temperature in the oven rarely match, and sometimes differ by 100 degrees F. Even new ovens. Therefore, for the best results, an oven thermometer is critical. (Unless your oven only has gas mark, I suppose.)

Back in March/April 2002, Cook's Illustrated reviewed 8 oven thermometers. As part of the study, they compared 16 home ovens and only 9 of the 16 were within +/- 25 F of the target of 350 F. Their favorite was the Taylor Classic Oven Guide (~$15), with high marks also going to the Component MOTI and Cooper 24HP. The full article might be at the Cook's Illustrated website, but is probably behind a dollar-wall. I've had a Taylor for a few years and it has improved my baking experience by removing one source of uncertainty.

This is definitely a handy conversion list to have on hand. Thanks!

Paz

In order to be a more versatile baker, I have a digital cooking thermometer. Not only can I accurately gauge the temperature of a candy or roast (I'm vegetarian; tofubeast internal temperature is, you know, so extremely important), but I can bake on a stove. This is important, since I've wanted to make bread for my kosher friends using a dorm kitchen, and kosherizing a dorm oven is rather difficult (they tell me it requires a blowtorch), whereas a new large pot and a thermometer can get to a rather high temperature.

I forgot to include this tale in my post about oven thermometers above: Back in grad school (ME at UC Berkeley), I borrowed a type K thermocouple (with heat resistant wire insulation) and a thermocouple reader and brought it home to check out my oven. Over the course of an afternoon I created a calibration chart for the oven dial. If I remember correctly, the offset was relatively constant across the range, about 50 F. My housemates made jokes about this for a long time. And still ask if I can calibrate their oven.

But the super engineer way would be to bring home 9 or 16 or more thermocouples, arrange them in a 3-D grid in the oven, and then run it at each temperature setting until steady state was reached. Then input the data into SigmaPlot or other 3-D plotting program. The data and plots could help you know where the hot spots are and etc.

Kitchen Parade wrote:



The reason you can't find an easy reference is there is no direct correllation of weight to volume. This is why many baking recipes specify weight: because volume is just too innacurate.

For example, 1/2 cup of kosher salt uniformly weighs about 64 grams. But 1/2 cup of flour, although it will weigh similarly to the salt, can vary tremendously by how densely it's "packed" when you take your 1/2 cup measurement. It could weigh as little as 60g and as much as 72g. (This is why recipes which call for cups of flour may tell you to measure it by "spooning it lightly" into the cup and levelling it off without any kind of packing or tamping down). And 1/2 cup of sugar (white, granulated) uniformly weighs almost double the kosher salt: about 104-106 grams.

It gets stickier when you start to measure items which are not granular by nature. "A cup of choclate chips" will vary greatly in terms of overall chocolate depending on how large the chips are, and what their shape is. Smaller, rectangular-shaped chips will give you far more weight (and therefore, far more chocolate) per cup than larger, teardrop-shaped ones.

So there's no universal conversion chart you could get.....you could only have a chart that mentioned each ingredient by name.

Or, invest $13 in a small digital kitchen scale which will last you a lifetime, and which you'll find you use all the time once you have it... :)

I'm not sure there's an answer to this, but here goes anyway...
Say I have a chiller with a 38,000btu/hr (11,137 watts) capacity and it's running all out. Say the only thing it's cooling is a 1'x1'x1' box. With the chiller running, the surface of the box is room temp. If the chiller takes out what the box puts in, the box must be generating 38,000btu/hr. Assuming all sorts of stuff to make this problem simple, can I determine the temperature of the surface of the box when the chiller is off?

Thanks
Paul.James@HS.UTC.com

It is very simple to find it. However, you should first know what the box is made up of..cause you are gonna search for the heat conversion coefficient(h) and thermal conductivity(k) of the box based on the material from any chemical engineering handbook. Then, you can calculate the surface temperature of the box by using heat transfer equations.

I'm trying to find out the cost of baking for an hour at 300º
using a commercial gas oven.
cost of propane is variable, a gallon of propane has about 90k BTU
so looking for the btu per hour consumption
any help ?

I've been on the net for an hour searching

www.fareshare.net/conversions-volume-to-weight.html is a list by item. you can also use the calculator at www.nal.usda.gov/fnic/foodcomp/search/ to get weight conversions for items in the USDA/FDA food database, along with their nutritional values for the quantities you input.

I remember being told about the "British Standard Sponge Cake"

Which was a recipe that was to followed exactly as writen.

From the results any problems with the oven could be diagnosed - Temperature, Slope, Hot Spots.

this article makes me laugh. i was raised that "the closest a man can get to being god was an engineer." (a pe or strong mechanical backgroud, and some civil was encouraged. certainly none of the ee types from our family.

i'll never forget what my mother told my dad after he had recalibrated the oven knob with a marker and masking tape. he was trying to tell her how she'd cook so much better now that is was corrected (it was 25 degrees off @350 f) from the traceable pryrometer he had brought home. he cooked that week. which led to the "if you could teach a monkey to read he could cook anything the finest chef could" arguement. thanks for the memory. b

The Gas Mark system is a feedback loop. The knob sets the cut of point for the gas supply in a similar way to a steam engine governor. As the oven reaches temperature the gas supply is reduced to a level that no longer maintains the set temperature, the fall in temperature re-opens the valve.

It's a mechanical system, which is why ovens vary between individuals but are consistant in their own responses.

It is Cel[u:b06d129c4d]s[/u:b06d129c4d]ius.
My gas-powered oven has a scale of 120°C to 280°C marked every 20 degrees.

Ah, thanks for catching that. I fixed it.

thank you very much you rescue my cake...
it is quite difficult to bake a cake in a foreign country..
at first the ingreedienz and than the difficulties with the gas oven

by the way I'm from germany
thanks a lot

:shock:
We are at present residing in Kuwait and tried to learn to cook some of the regional dishes but when we found cookbooks that had interesting items all the temperatures used were referred to vaguely as in-low heat, medium heat etc. hard to decide what this translated to -Thanks for the reference chart

just Google, 'how can I calibrate an electric oven'
Very simple for older non-digital control ovens.
even I was able to correct my oven which was off by 50 degrees

wow, what a comprehensive list!

Can someone explain why some recipes specify placing food in the middle of the oven, and others at the top, even if you're only cooking one thing?

Presumably it can't just be that the top is hotter, or one would place things there by default for energy efficiency. Possibilities that spring to mind include:
* Radiant heat from the top inside surface of the oven can be used to brown the food
* It's something about airflow and humidity

I'd love to understand this - thanks for any tips.

Adrian.

You've got it. Mainly it's due to the radiant heat from the top of the oven than heats food from above faster than below. Most recipes ask you to place the food in the middle so heating from radiation is similar from above and below.

If you do have an oven thermometer you trust;Set the oven to a moderate heat like 350°F,Pull the knob off the stove front and you should find a slotted piece of metal behind it that has two like size 00 Philips screws. Loosen and turn the slotted piece so that when you put the knob back on, it reads what the thermometer says. Tighten the screws back.

Its been a long time since I did this so maybe the new electronic controls will be different but I'll bet those have instructions online.

a gram is a milliliter is a cubic centimeter. Five mL is 1 tsp. 15 mL is a Tbsp. 16 Tbsp is a cup, so 240 mL is a cup. This only works for volume, not mass! 240 mL is 0.24 L.

Conversely, a liter is 1000 mL, so 1000/240 = 4.16 cups.

For mass, a kilogram is 2.2 pounds, or 35.2 ounces by weight.

Hope this helps.