Boil water then cook on gas?

[OM2]

Is it cheaper to boil water and then cook on gas?
Boiling water in a kettle is cheap because it heats so quickly - so I understand.

If cooking on gas, does it make sense to boil in kettle first and then cook on the hob?

Thanks.

 

[motorbiking]

Kettles are about 10% more efficient as less heat is lost outside the vessel. However Gas is typically significantly cheaper. So unless you are using a cheap rate/battery/solar storage etc - its going to be cheaper via gas.

 

[OM2]

To boil same water from cold to boiling takes 6-7 minutes.

Does that change the equation?

The other thing is, boiling water in a kettle - we always boil more than is needed.

 

[jacko555]

I boil kettle then decant onto gas hob.
For convenience.
Some interesting stuff here https://www.diynot.com/diy/threads/boiling-water.509334/

Without measuring, I reckon cheaper to kettle and decant, especially when boiling a few litres for pasta. Kettle is more efficient at getting the energy into the water

 

[Mr Chibs]

Put less in the kettle

 

[Harry Bloomfield]

An electric kettle is close to 100% efficient, the only losses are due to heat lost on the kettle surface, whilst it is heating up. A pan or kettle on a gas hob is around 25% efficient, but gas is around 25% the cost of electric, so assuming the 75% is just wasted heat, there is not much between them. However, in winter, the 75% might not be entirely wasted heat, it can warm the room. In summer use either the electric kettle or hob, in winter the gas hob wins.

 

[Justin Passing]

Put a small pan on the wok burner because it's quickest, and how much more do you lose? Half?

 

[JonathanM]

A pan or kettle on a gas hob is around 25% efficient

Presumably that's why the hob is so slow, then? My biggest hob burner is 2.9KW and my kettle is 3KW. So the hob will take four times longer to boil the same amount of water.

 

[big-all]

An electric kettle is close to 100% efficient, the only losses are due to heat lost on the kettle surface, whilst it is heating up. A pan or kettle on a gas hob is around 25% efficient, but gas is around 25% the cost of electric, so assuming the 75% is just wasted heat, there is not much between them. However, in winter, the 75% might not be entirely wasted heat, it can warm the room. In summer use either the electric kettle or hob, in winter the gas hob wins.

Exactly the point, look at the bigger picture boil a kettle by electric cost you say 10p with 1p worth seeping into the room through heat loss
same 10p will get you 3x the energy from gas so the equivilent off around 27p worth to the room for free

now not exact or accurate but a close idea off how it works

 

[JP_]

I stopped using my electric kettle almost a year ago. Boil on gas.

 

[JonathanM]

I stopped using my electric kettle almost a year ago. Boil on gas.

Does it taste better? Boiled kettle water always tastes a bit funny, but I don't know whether that is down to the boiling or the kettle.

 

[jacko555]

Exactly the point, look at the bigger picture boil a kettle by electric cost you say 10p with 1p worth seeping into the room through heat loss
same 10p will get you 3x the energy from gas so the equivilent off around 27p worth to the room for free

Yeah, but when cooking on gas I keep the extractor on, especially when boiling water.
Where does that heat go?

Either way, kettle for convenience for me. Who cares about efficiency

 

[JP_]

Does it taste better? Boiled kettle water always tastes a bit funny, but I don't know whether that is down to the boiling or the kettle.

Didn't make want difference. No limescale buildup problems either.

 

[JP_]

Yeah, but when cooking on gas I keep the extractor on, especially when boiling water.
Where does that heat go?

Either way, kettle for convenience for me. Who cares about efficiency

If you boil water in a hob use a hob kettle with whistle. This loses less stream than an electric kettle.

 

[StephenStephen]

I heat the amount of water I need to cook in a vacuum insulated kettle set to 90 degrees, running off battery stored solar/cheap rate electricity.

...I do like a cheap hobby with lots of trivial details!