What is the most cost effective way to boil water for cooking pasta?
August 11, 2025
Is it more cost effective to boil the kettle and then keep cooking the pasta on the hob, or should i take warm tap water and heat it until boiling using the hob? For context I have a gas stove
18 comments
Boil lots at once, bag it up and put it in the freezer in the portions you want!
[deleted]
Kettle’s are more efficient. But some things are better brought up to heat. pasta is better put in boiling water. So Kettle can be more efficient. However, how much money you *actually* save may be so little. Up to you.
Kettle. It’s by far the most cost effective, quick, efficient and safe way to boil water.
A lot of the energy goes elsewhere on the hob.
Kettle, they are more energy efficient. The difference is negligible though.
Gas is cheaper per unit of energy used, but a gas hob is considerably less efficient than an electric kettle. So it probably ends up about even. In any case, cooking isn’t a big enough part of total energy consumption that you’re going to be able to meaningfully save money.
It’s more energy efficient to boil it in the kettle than it is to boil it on a gas hob. If you had electric or induction then it wouldn’t really make any difference but gas definitely uses more energy to boil water than a kettle.
However, where it gets complicated is the fact that gas is often cheaper for the same amount of energy than electricity is. So say that you need 20% more energy to boil water with gas but the gas is 30% cheaper than electricity it’s actually cheaper to use gas even though it’s less efficient.
The kettle is more efficient, and designed to bring water to a boil quickly.
Using the hot tap, waiting for the water to get hot and then boiling that water will take longer and be less efficient than just starting with cold water.
If you’re in a house that still uses a hot water tank, it’s best to not use the hot tap as potable water.
Kettle wastes less energy (kettle > electric hob)
Gas is cheaper (gas > electric hob)
No idea on microwave
However the main thing is don’t boil water you don’t need. Fill the kettle/whatever just the right amount.
Put water in the pan you’re cooking the pasta in, then boil it and cook pasta.
If you heat it in the kettle first then you’ll be putting hot water in a cold pan and it still takes time for the water to be boiling again.
Gas is cheaper than electric
Electricity is more expensive than gas to heat water but kettles are very good at energy efficiency. You’re literally saving about 50p in a year doing it via kettle
Surely it’s quicker to put the pasta into the kettle, and cook it there. Cuts out the middle-man of using pans. You can make tea and coffee the same way. Probably all three at once if you’re short of time.
Oh my god, finally the work I did in my first year of uni comes in handy. We tested about a hundred kettles on the market at the time, controlling for initial water temp, ambient temp, even actual mains voltage. The stated wattage vs what it actually used was noted. E.G. A kettle that used half the current for twice the duration wouldn’t be penalised. It was total kilojoules input vs kilojoules put into heating water. This was calculated from the known specific heat capacity.
The electric kettle starting with cold water is the most efficient. And within that:
The most efficient kettles were those cheap nasty ones with an exposed heating element directly in the water, plastic bodies.
Much worse were the expensive models with the heating element integrated into a flat base.
Absolutely dogshit were the ‘fancy’ ones with glass or metal bodies, integrated heating elements and perhaps lights on them.
The absolutely terrible £5 Tesco Value level models that didn’t even have a separate base were by far the best at the job of heating water.
Longevity and how much limescale would build up on the exposed elements wasn’t tested.
Cook the pasta in the kettle as that’s the cheapest way to boil water.
Magnifying glass to heat some water.
Some weird answers here… The energy needed to boil water doesn’t change. It’s 334,720 Joules from 20 to 100 degrees per litre.
If you allow heat to escape, it loses efficiency, if you boil in a vacuum, it’s faster.
A kettle is more efficient than a pot without a lid, a pot with a tight fitting lid will be more efficient than the kettle, but can’t deliver the same amount of energy as the kettle, so it takes longer. But gas is a quarter the price of electricity. So as long as it takes less than 4 times as long, using the gas will cost less to boil the water.
Alternatively you can use induction and just throw wattage at the problem.
Dry pasta should turn soft and edible if you just leave in in cold water for about a day, so if you did that and just brought it to the boil at the end you could save a lot of gas. Not sure the saving is worth the effort tho, got to be less annoying ways to reduce costs.
18 comments
Boil lots at once, bag it up and put it in the freezer in the portions you want!
[deleted]
Kettle’s are more efficient. But some things are better brought up to heat. pasta is better put in boiling water. So Kettle can be more efficient. However, how much money you *actually* save may be so little. Up to you.
Kettle. It’s by far the most cost effective, quick, efficient and safe way to boil water.
A lot of the energy goes elsewhere on the hob.
Kettle, they are more energy efficient. The difference is negligible though.
Gas is cheaper per unit of energy used, but a gas hob is considerably less efficient than an electric kettle. So it probably ends up about even. In any case, cooking isn’t a big enough part of total energy consumption that you’re going to be able to meaningfully save money.
It’s more energy efficient to boil it in the kettle than it is to boil it on a gas hob. If you had electric or induction then it wouldn’t really make any difference but gas definitely uses more energy to boil water than a kettle.
However, where it gets complicated is the fact that gas is often cheaper for the same amount of energy than electricity is. So say that you need 20% more energy to boil water with gas but the gas is 30% cheaper than electricity it’s actually cheaper to use gas even though it’s less efficient.
[Based on this video, the kettle is the fasted was to heat the water. ](https://www.youtube.com/watch?v=_yMMTVVJI4c&ab_channel=TechnologyConnections)
The kettle is more efficient, and designed to bring water to a boil quickly.
Using the hot tap, waiting for the water to get hot and then boiling that water will take longer and be less efficient than just starting with cold water.
If you’re in a house that still uses a hot water tank, it’s best to not use the hot tap as potable water.
Kettle wastes less energy (kettle > electric hob)
Gas is cheaper (gas > electric hob)
No idea on microwave
However the main thing is don’t boil water you don’t need. Fill the kettle/whatever just the right amount.
Put water in the pan you’re cooking the pasta in, then boil it and cook pasta.
If you heat it in the kettle first then you’ll be putting hot water in a cold pan and it still takes time for the water to be boiling again.
Gas is cheaper than electric
Electricity is more expensive than gas to heat water but kettles are very good at energy efficiency. You’re literally saving about 50p in a year doing it via kettle
Surely it’s quicker to put the pasta into the kettle, and cook it there. Cuts out the middle-man of using pans. You can make tea and coffee the same way. Probably all three at once if you’re short of time.
Oh my god, finally the work I did in my first year of uni comes in handy. We tested about a hundred kettles on the market at the time, controlling for initial water temp, ambient temp, even actual mains voltage. The stated wattage vs what it actually used was noted. E.G. A kettle that used half the current for twice the duration wouldn’t be penalised. It was total kilojoules input vs kilojoules put into heating water. This was calculated from the known specific heat capacity.
The electric kettle starting with cold water is the most efficient. And within that:
The most efficient kettles were those cheap nasty ones with an exposed heating element directly in the water, plastic bodies.
Much worse were the expensive models with the heating element integrated into a flat base.
Absolutely dogshit were the ‘fancy’ ones with glass or metal bodies, integrated heating elements and perhaps lights on them.
The absolutely terrible £5 Tesco Value level models that didn’t even have a separate base were by far the best at the job of heating water.
Longevity and how much limescale would build up on the exposed elements wasn’t tested.
Cook the pasta in the kettle as that’s the cheapest way to boil water.
Magnifying glass to heat some water.
Some weird answers here… The energy needed to boil water doesn’t change. It’s 334,720 Joules from 20 to 100 degrees per litre.
If you allow heat to escape, it loses efficiency, if you boil in a vacuum, it’s faster.
A kettle is more efficient than a pot without a lid, a pot with a tight fitting lid will be more efficient than the kettle, but can’t deliver the same amount of energy as the kettle, so it takes longer. But gas is a quarter the price of electricity. So as long as it takes less than 4 times as long, using the gas will cost less to boil the water.
Alternatively you can use induction and just throw wattage at the problem.
Dry pasta should turn soft and edible if you just leave in in cold water for about a day, so if you did that and just brought it to the boil at the end you could save a lot of gas. Not sure the saving is worth the effort tho, got to be less annoying ways to reduce costs.