Decarbonising cooking

Decarbonizing our homes can seem like a massive undertaking, especially when looking at whole house retrofit!!
In our home, our changing financial circumstances have taken us from looking at whole house renovations, to finding smaller less costly and effective ways of reducing our energy costs, usage and other waste.
Cooking and food storage has been a focus for quite a while now.
We currently have a duel fuel, gas top hob, which we use a lot, batch cooking to save time and energy also. However, with the sharp rise of gas prices and the pressing need to decarbonize, we know it’s a win win to get rid of the gas hob.
After some research, we have learned how induction hobs offer the most energy efficient cooking and we are awaiting the arrival of an induction hob.
In addition to this, we read an article about induction kettles - also more energy efficient to boil than an electric kettle. PLUS - you are far less likely to have to replace it because it’s always the electrical components that fail on plug in kettles - less waste to landfill!!
After researching induction kettles we settled on a Judge - ‘no frills’ JK04 stainless steel model with a 25 yr guarantee! cost - £33.
While looking at the most energy efficient cooking, pressure cookers kept on popping up. :thinking: These cook in a third off the time it takes via other methods. Obviously, there is an art to cooking in a pressure cooker, but with such massively reduced cook times , I don’t feel we can afford to ignore pressure cookers and I’m now reading about ‘the art of pressure cooking’.

It times like this, that I wish I was more technically minded and able to compare and present the energy savings and costs to you. Perhaps someone here can talk to this topic and support my layman’s research and decisions with some solid data.

I’ll keep you posted and let you know how we get on with cooking and boiling water on an induction hob!! Hopefully, I’ll be able to share some energy saving pressure cooking experiences too. :smiley:

I don’t think an induction kettle is more energy efficient than an electric one but they are efficient and better for the other reasons you mention.

My mother cooked a lot in a pressure cooker and so did I when I left home. In fact I did so until my old pressure cooker started to corrode. High pressure super heated steam and corroded containers are a very dangerous combination so out went the pressure cooker and in came the microwave.

Pressure cooking is a good way to cook but do be aware that it reduces the vitamin content of fruit and vegetables.

It isn’t easy to amend existing recipes so you will need a new cookbook but you will probably find that a decent pressure cooker comes with a small one anyway.

I have had an induction hob for 17 years and would never revert to gas. I bought mine for safety reasons but the energy efficiency and speed of response are second to none.

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Love your feedback here Tim. It’s very useful. I haven’t bought a pressure cooker yet …I’m going to have a good read first and check it’s not too much of a risky business - exploding pots :grimacing:
You got me thinking about microwaves as an alternative!

Really looking forward to getting the induction hob and kettle though - they feel like a win win.

All the best
Carla

I’ve been thinking along the same lines, and will replace my gas hob with induction. But always keeping an eye on embedded carbon, I’m keen to keep appliances as long as possible as well! My mum gave me her old pressure cooker when I went off to uni in 1973, and it’s still going strong. But I don’t use it much, usually just for dried beans and making stock. I use my microwave several times a week though, mainly to reheat those home cooked extra portions from the freezer.

1973: my guess is the pressure cooker is aluminium. You will need to replace it if you get an induction hob.
Mine was about the same vintage and corroded at the join between lid and pressure release valve.

Yes, excellent for dried beans. Don’t forget the Christmas pud.

Yes, it won’t work on induction, but I can live without a pressure cooker :slightly_smiling_face:. I checked and all my other pots and pans will be fine.

Hi all,
I too have been thinking about cooking but from a slightly different perspective- I have been monitoring our indoor air quality as we have an old Hotpoint gas stove. We currently do toast on it but can monitor a spike in CO2 and volatile organic compounds if we get the timing wrong and char the hot cross buns! In a matter of minutes we can double or treble the CO2 level in a reasonably large kitchen. Doing a roast is unbelievably bad. I am a fan of the pressure cooker but have not fired it in anger for a while & most meals are completed in 30 minutes or less.
From an energy efficiency and air quality point of view I think you should consider the George foreman (fat burner). I have been playing around with this and have done panini and garlic bread in minutes. I have scoped out a few recipes and it is really quick, hence I am using the gas stove less.

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Embedded carbon is at the forefront of my mind too. It lead me to upcycle my old kitchen - which has been quite a transformation - a very satisfying project - saving us money, carbon and an affirmation that we are very capable DIYers.

Thinking ahead about solutions for laundry, I have been following Ebac, looking at dehumidifiers
for drying and reducing moisture, as well as energy efficient washing machines with microfiber filters.
Ebac are British based and I’m hoping they are going to develop their business to have a good circular economy for customers in parts, repairs and recycling.
They seem to be aiming in the right direction for householders and the environment.
I liked how they challenged Which in how they rate the best dehumidifiers , that energy efficiency is not defined in ‘the model that collects the most water’… it is the model which can function and self regulate to the fluctuating humidity in the environment that is more efficient and effective.

Going back to embedded carbon , our gas cooker does still very much work, but getting rid of it feels right , just as a first step away from fossil fuel .
I really try to utilize our larger than average freezer through batch cooking… Not that food stays in there long ! Our girls often take the precooked meals to Uni - which of course I love cause I know they’re eating well and don’t have to worry about cooking when studying.

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Our EBAC dehumidifier is probably 20 years old and still going strong. Given it effectively contains a miniature heat pump I have wondered if they are developing a scaled up version for heating.

Induction hobs are a way of transferring variable amounts of electrical energy into a wide range of pans in different configurations without electrical contacts.

Induction kettles are less efficient than resistive kettles because converting electricity into a magnetic field and then inducing it into the hot water heat exchanger, ends up wasting more heat via the electronics and other conversion losses.

The worst part of boiling water is boiling too much. I’d recommend getting a good quality tap with instant, preferably filtered, boiling water so that you only use as much as you need rather than having a few cups sitting in your kettle cooling-off by accident.

If you don’t mind unfiltered water then the tap can use hot water from your domestic hot water tank, at 65 degrees, which can be heated via a heat pump (which is much more efficient). Then your instant boiling water tap tops up the temperature to 100 degrees using resistive (ohmic) heat.

However, we are not talking about that much energy in the grand scheme of things, so I wouldn’t worry about the small energy savings. There are better things to worry about at present that will have a large impact and deserve more of our attention.

Cooking with lids on is a big one. The problem is water can boil and froth and overspill, eliminating any energy saving. So getting the correct power output is key. Highly variable hob power outputs are needed for this. At the moment we always have the 1-10 increments, which I’d like to see become infinitely variable.

Having good pans with recessed rims to receive the lids give you a bit more time before over boiling occurs. You don’t get horizontal spitting all over your hob either. I like pan lids with an integrated colander around the sides, with a corresponding pouring outlet bent into the pan to let variable amounts of steam to blow off because it’s a pain to micromanage each hob perfectly.

Do not pour hot water down the drain. It is not good for the plumbing, but it’s also wasted heat. Leave it in a spare pan with the lid on to prevent evaporative cooling, then let it cool to near room temperature before pouring away. For example, pasta water/ potato water etc.

Induction hobs vary output by pulsing the magnetic field. 50% output is typically provided by turning off the coils for 50% of the time. My experience is that you need to choose the right induction hob size, to have the correct power output. It is better to have the hob on 100% power all the time, than to use a larger one and switching it on and off frequently to average out the power to the same amount. Typically, you only need very high output at the beginning, such a boiling water in the pan quickly, then the power output can be greatly reduced. Induction hobs can provide huge power outputs, that are much greater than it’s gas equivalents.

Induction hobs have varying technologies that allow them to use the same 2.5-5kW electrical supply and to send most of it to one hob temporarily, whilst reducing the potential power output to the other hobs. This is often called a boost feature, etc. No doubt there will be a lot of marketing jargon to read past to find this out.

It is just as important to get good quality ferrous pans with large thermal mass - I like the traditional cast iron ones, or the heavy stainless ones used in pro kitchens. Keep an eye out for these on auction sites and car boot sales. They also look fantastic.

The reason these heavy pans are significant is that they spread the heat evenly if the hob is smaller than the pan. But also it needs to be heavy to smooth out the temperature increases from the pulsed heat on lower power outputs.

However, the largest challenge is ventilation of cooking contaminants, including humidity. A makeup air system, with a fan supplying fresh air around your hob, with a well-placed extractor hood exhausting the contaminated air, is the best way to provide the necessary ventilation.

I haven’t seen these systems with a heat recovery heat exchanger, so it’s just a small amount of energy we’ll just have to lose for the sake of simplicity and low maintenance. It will still cost a pretty penny as they’re not that common and considered a luxury and premium component.

The cooker hood extractor fan is separate from the kitchen MHRV return.

Retrofits often have an open plan arrangement with the dining room by having a lintel supporting the floor system above where a load bearing wall once was. The lintel creates a partial baffle from those contaminants spreading across the room. Although food hatches are no longer fashionable, I still like kitchen islands with overhead storage to help separate some spaces, whilst still keeping it open plan enough to feel like you’re part of the action.

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I’m a big fan of pressure cookers!

The other is microwave/fan oven combination ovens. They simultaneously cook with microwaves from the inside, and with conventional conduction from the outside. A jacket potato now takes 25 minutes instead of 45 minutes. Learning when this is and is not a good way to cook for taste will be part of being an experienced cook.

Very few ovens are well air sealed and insulated, nor do they contain ways of dehumidifying air inside the oven efficiently. I suspect we have a while to go before they make good quality, durable and serviceable ovens like this.

Again, sometimes simplicity is worth the energy loss. Ovens probably fit into this category for the time being.

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Be careful cooking beans in a pressure cooker. My dad’s exploded, all over the house! Literally, every wall was covered, it bounced out of the kitchen. I think he was lucky to survive!

Hi!

I have an instant pot electronic pressure cooker / slow cooker combi. Very efficient.

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