Oven temps

[Dave]

Wifey is beginning to think that our gas oven isn't working as it should, ie, things are taking too long to cook. She's had some potatoes in there (she's making 'Slimming World chips'), on gas mark 9, for almost 50 minutes now and they're almost, but not quite, ready yet. On the other hand, a joint of beef roasts in what she considers 'normal' time, although she does come from the 'slow cook for long time' school of thought on that.

How does one go about checking correct operation of gas oven and making sure that 'gas mark 9' really is gas mark 9 - and what do you do if it isn't working as it should?

[Adrian]

[Dave]

This is one of those 'Doh' moments isn't it - overthinking a problem and looking for technical ways, when all it needs is a two or three quid thermometer lol

Cheers

[The Natural Philosopher]

you can buy a thermometer than hangs dfrom a shelf inside for peanuts

[Another John]

Oven temps aside (since you're going to try a thermometer : do let us know what you find won't you?) ....

I personally have begun to suspect that our gas is either (a) depressurising around teatime or (b) being "watered down"[1]. For example I can bring a pan of water to the boil, throw in the spuds or pasta, and then it's a struggle to keep it boiling unless I put it on the "big" ring.

I haven't got around to contacting anyone yet (who do I contact? EoN (who I pay for our gas), or someone else?), but I'm seriously thinking about it: I first noticed it several weeks ago.

John

[1] I only suspect (b) because a few years ago I noticed that the supplier was notifying "calorific value" of the gas supplied, on the bills -- in other words, it could vary from month to month. Previous to that it never occurred to me that gas could be of different strength, any more than water can.

[EricP]

+1

Cheap cheerful and effective. Or if you want a toy, get an IR thermometer. They provide hours of happy amusement.

[Adrian]

Umm, you have just lobbed a relatively large room temperature mass into the water - so, yes, the water will lose temperature rapidly.

Oh, and don't forget to salt the water lightly (and, for pasta, a few drops of oil helps to stop it sticking)...

[Tim+]

One of the big differences I noticed after moving from a gas oven to an electric fan oven was how much less the latter was effected by the "wet load".

Fill a gas oven with baking potatoes and you can be sure they'll take twice as long as you expect. Do the same with a fan oven and the just seem to cook at the prescribed pace. I dunno whether it's down to the position of the oven thermostat or what, but fan ovens just seem to "do what it says on the tin". I wouldn't go back to a gas oven now.

Tim

[Adrian]

Umm, I think that's the "fan" bit, rather than the "electric" bit. There are gas fan ovens and electric non-fan ovens.

FWIW, I agree with you on the fan-over-non-fan bit, but am totally agnostic on the gas vs electric bit. Gas hob's a no-brainer, though.

[newshound]

Variable calorific value has been the case for a long time, but I don't believe the variation is very much. I would be surprised, personally, if "they" are deliberately "watering it down" (by diluting with nitrogen) for the same reason that electricity companies normally keep the voltage close to 240: they sell more energy that way. It's possible that your pressure drops a bit when demand is high (because of flow losses). It's also possible that your supply pipe has become restricted somewhere over time (roadworks, subsidence, trees?). Do you have gas CH? Does the cooker flame reduce when the boiler lights?

[polygonum]

Which way round? If you have no brain you'd get a gas hob? Or... :-)

FWIW I'd have chosen gas before I experienced using an induction hob.

[Adrian]

I've used induction hobs. Thanks, no thanks.

[alan]

Commercially made pasta probably already contains tons of salt.

[Clive George]

Ingredient : Durum wheat semolina

That's ingredient, not ingredients.

[Dave Liquorice]

Gas has the edge over induction for me but either are far far better than any other electric hob.

[harryagain]

Calorific value of gas is less variable than it used to be when it came from coal. The only likely "contaminant" gas these days is CO2 which is allegedly removed. Your gas pressure may be falling at certain times, the only way to tell is with a "U tube" water gauge. There is a pressure reducing valve/governor next to your meter may be faulty. If so you could be loosing money. ie paying for gas you don't get. The meter only measures volume, if the pressure is down you get less gas.

As an aside, this likely to be an inceasing problem. There are plans afoot for biogas from anerobic digesters to be directly injected into the mains. This gas contains a mixture of methane and CO2. The mixture depends on what the biogas is made from. Eg, Cowshit = more CO2, Food waste = less CO2

I dunno how this can be regulated. We have a local plant, they are running their vans off of it too. It will lead to loss of boiler efficieny too. It may be we have to have boilers with O2 analysers in the combustion gas in the future, so adjusting gas/air ratio.

Most Biogas plants turn it into electricity.

[Adrian]

That's not the totality of ingredients. Unless, of course, you've just bought a bag of flour.

[Tim+]

That probably accounts for most of it but I wonder how much variation there is in the heat output of gas ovens? Looking at ads (and available tech spec) it's surprisingly hard to find out the kW (or BTU) output of typical gas ovens.

I suspect some manufacturers skimp on the heat output side of things knowing that when empty, the oven will easily meet the temperature requirements. When full of wet stuff however...

Tim

[Vir Campestris]

I suggest you try an induction hob.

Andy

[spuorgelgoog]

That's what my bag of pasta says.

And under nutritional information, both sodium and salt equivalent are listed as 'trace'

That's for dried pasta.

For fresh pasta, Tesco's website says

Durum Wheat Semolina,'00'Wheat Flour ,Egg (15%) ,Water

and gives salt as 'trace' per 100g and 0.1g per 175g cooked.

The ready-filled stuff eg cheese tortelloni, has 0.8g salt equivalent per 100g, and 2g or 33% RDA per serving

Owain