SLiCK Solar Baking – The Gorilla Sun Oven

Baking is a fine example of what solar cooking can deliver in the UK. This is a lazy and unique way to craft your daily bread. With amazing results. Let me show you how I do it:IMG_2836 IMG_2826

Like all things solar you want to start early. In our case the night before. Mix your living yeast with flour and all other ingredients. Follow your own recipe, I have mine, it changes. Cover and leave your mixture overnight to rise (you know you’ve got sun tomorrow, right?).

Morning…now you want to catch all the rays so set out your Gorilla Sun Oven early, it will do a slow warm up in the weak morning sun. With a bit more flour knock back your dough and shape.  Its got to be oven sized – baguettes, bagels, baps – whatever you can get in there. Let it rise for half an hour or so. Make sure you can lift it easily, to transfer onto your hot baking tray for a quick insert, I use baking paper for convenience.

IMG_2592 IMG_2645Now for some solar cooking theory. This is not a fuel hungry wood-oven with hot stones and excessive heat. Its a glass tube. A very special glass tube. Protected by a super insulating vacuum the inner wall gets plenty hot from the sun, but theres not a lot of wall. It heats the air inside and also conducts to what you’re putting in. You have to conserve the heat  because it takes time to warm up. The distance from the sun is 93 million miles, and then clouds get in the way, so don’t expect miracles! IMG_2253IMG_2814

Quick as you can, pop the bung, remove the hot tray and carefully position the bread. Bear in mind it will rise further in the tube (‘bread spring’). Get it back in and secure the bung, which needs to remain loose but not fall off, repeat ‘not fall off’.

Now relax, go swimming, hot yoga, sunbathe, whatever you do. Don’t be tempted to look inside, don’t waste heat – its just the sun, it needs your help. Do nothing. Or if you want, adjust it after an hour by keeping the long axis at right angles to the sun. 5 seconds work, max.

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1 hour – bread smelling steam is escaping, air temp inside is over 100°C
2 hours – its kind of done (Maillard reaction happening) 140-165°C
2½ -3 hours – crispy brown crust, patisserie in you garden kind of thing (if you did it right and the sun came out to play)

Disclaimer: This method only works with a solar vacuum tube oven in our UK sun. Times approximate. I’ve tried most other solar cooker types here and they just don’t cut it yet, for this application.

Author: Stewart MacLachlan, London – ‘Solar Bake Meister UK’













Pictures taken and bread baked between December 2016 and June 2017 in London, UK 51’30 North. Visit our shop section if you’re interested in a tube or other cooker. Help spread the word!

Copyright Stewart Maclachlan 2017

Solar Cooking at the Cambridge Museum of Technology

SLiCK were invited in mid November to the Pivotal event at the Cambridge Museum of Technology. Watching the forecast we confirmed attendance a few days ahead, not knowing what the expect. It turned out to be a sunny Autumn day.

The venue was an atmospheric Victorian pumping station on the River Cam.


Our ‘solar cooking window’ was short with solar mid-day around 11:00am and low sun angles. I’d no experience of doing a demo at this time of year and like most solar cooks I’m still finding my way about. Hungry for sunbeams I set up early. Look at those shadows!

It was pretty cold, around 6°C – much of the event was held indoors in the museum or its out-buildings. Outside we had a great spot with direct sun. Solar cookers take time to warm up, unlike powerful fossil fuel using devices. I also needed a warm up and was grateful for my small display of rocket cookstoves, keeping an Ecozoom Versa on all the time. Combined with the sunshine and the warm reception, this kept things very pleasant indeed!


I’d pre-made some bhajis/pakoras to reheat in the evacuated tube cookers ( SLiCK SM70’s)  and handed these out to visitors, careful not to lose too much heat as the spicy smell wafted around. I was also able to display a number of panel cookers in operation, (the best operation was the Lightoven), and my old faithful the Sun Oven, which after strong use for years is looking battered, but still heating up nicely.

The solar cookers need regular aiming in winter, the suns position changes fast in the sky, as the earth rotates. I also had to watch out for shadows sneaking in, as the sun dipped at noon.

Visitors were very interested indeed, the majority having never seeing a solar cooker before. People twigged to the idea of using a fireless cooker with a rocket stove and a solar cooker in combination. This allows 24 hour low impact, zero fossil fuel options for cooking.

Were not trying to say we should do this at all times, but we can work together to raise awareness of options for direct solar cooking whenever possible, off grid, in the garden, wherever. By doing this we’re encouraging uptake elsewhere in the world, amongst those who have little choice but to burn wood from endangered forests. Event attendees were highly aware of these and other environmental issues.

So close to mid-winter (5 weeks hence) and at 52°N it was for me a great opportunity to demonstrate the suns power and to counter the often heard fallacy that solar cooking isn’t possible in the UK. If I can do this in November, summer will be a scorcher!

Our thanks to the people of Cambridge and those who set up a great event. Hope its sunny next year too!

Author Stewart Maclachlan – SLiCK UK 

Join the discussion on the Facebook group – Solar Cooking UK


SLiCK, UK to MAMA SOLAR AFRICA – EcoZoom ‘Jiko’ Stoves

Back in August we took our ad-hoc roadshow to the Green Gathering Festival in Wales. For four days we demo’d all things solar cooking. Because solar cookers cannot cook when the sun goes in, we also demonstrated rocket cook-stoves, and fireless cookers. In combination, these three technologies will provide hot food from morning to late evening, at very low energy cost. This low-carbon approach is known as ‘integrated cooking.’


Most people understand fire, so wood cookstoves are easily understood, but fireless cookers?, not so much. A fireless cooker is merely a very well insulated container allowing food to keep cooking after the heat source is removed. To raise awareness of this simple technology, we held a tongue-in-cheek ‘World Beauty Contest’ for fireless cookers, since only nice looking objects will last in your home. Visitors to our display were asked to vote for their favourite fireless cooker.



The winner, Faustine Wama, of Kenya, is also known as ‘Mama Solar’ in recognition of her tireless efforts to promote integrated cooking in east Africa. We thought we could best support her work by providing her with some very efficient, award winning charcoal stoves (known as ‘Jikos’ all over East Africa). These stoves burn charcoal about 70% more efficiently than the ubiquitous Jiko stoves, with 58% smoke reduction. Called the Ecozoom Jet, they have won awards, especially for Womens empowerment in the developing world.

Faustine was presented with three Zoom Jet stoves by on behalf of SLiCK by EcoZoom Kenya. Here you see her with a range of attractive fireless cookers, some solar cookers, and one of the Zoom Jet Jikos.

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They will allow her to demonstrate a very efficient combination of cooking technologies solar cookers for when the sun’s out, charcoal stoves when it’s not, and fireless cookers for saving charcoal and keeping the food warm, well into the evening, if required. These cooking options can save money, reduce pollution and slow the crazy deforestation rates in the area.


Old inefficient Jiko, New efficient Ecozoom Jet

She will be using them in her integrated cooking demonstrations and for use in a supported school. These will reduce the fuel costs for cooking which are a burden to the school, which doesn’t have much of anything. We will keep you posted on’Mama Solars’ demonstrations in East Africa when we can. Thanks to all who contributed to our effort! You can also donate a jet stove in the Nairobi slums -get in touch at EcoZoom UK

fireless-cookers sundowner

Authors: Dave Oxford/Stewart MacLachlan  – SLiCK UK

Special thanks to: Alex Key, Malaysia; Zoe Williams UK; Lee Wharton UK; Stanley, USA ;and Nabukelela, RSA (for ‘Tea Cosy Sikeleli iAfrica’), who all gained a commendation for their entries – great stuff guys

Seriously Low impact Cooking


SLiCK – Solar Cooking at the UK Green Gathering 2016

3322dfd6-a219-41ed-889e-a9ae5efac6b6 load-of-parabolics
The Green Gathering 2016 was SLiCK’s first roadshow. Solar cooking in the UK is carried out in variable weather but we got perfect conditions for the 4 day event. Our goal was to demonstrate practical solar cooking to visitors with as much theory as you can eat. This festival occupies a niche in the UK outdoor festival scene – it’s completely off-grid, running on wind, solar and people. This limits the scale but it remains a large and popular event with environmentally minded visitors from all over. It was a highly receptive crowd and most had never encountered a solar cooker before or were unfamiliar with the concept.

Our location benefited from a southern aspect, with all day sunshine possible. We experienced a lot of interest and learnt a lot.

What Solar Cookers did you have on Show?
We had a selection of all current types, along with some prototypes. While SLiCK markets two of the units below, our aim is to demonstrate all the types we can and always with an open and even handed approach.
Panel Cookers – The Lightoven ; The Rollins ; The Cookit
Vacuum Tube Cookers – The SM70 ; Wall Kettle ; Rand Naked
Solar Box Oven – The SunOven
Parabolic Dish – The SolSource ; The INOX

How did the Cooking Go?
All day solar cooking with multiple cooker types is a developing art. I’ll be expanding more on this in later posts, as the job of ‘solar chef’ has little precedent at this time. I guess its like managing a busy kitchen with ‘stacked’ cookstoves, closely watching food volumes, cooking times, solar energy inputs and meteorological conditions. All while talking to visitors and keeping an eye on hazards – its hot stuff!.
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To be sure SLiCK’s crew ate solar every day – our evening meal together was a combination of foods cooked during the day, kept piping hot in fireless cookers as necessary. All food (including hand out snacks) was vegetarian, delicious (if you ask me!) and with no accidents or burns.

What Events were held
Multiple Cookits and jar-in-jar containers were used for Dave Oxford’s workshop, ‘how to cook an egg in pure sunlight’. Attendees learnt about the physics of solar cooking whilst seeing it in action. We learnt a lot from this and will be developing the syllabus further.

The worlds first ‘Fireless Cooker Beauty Contest’ was held on our site. Well, more about this later, but a great selection of beauties was presented to our visitors, who voted for the prettiest over the festival period. Kenya’s Faustine Odaba  won this contest with her great selection, hand made by women there as a way of supplementing their income. We raised £100 in donations and 3 efficient and award winning Ecozoom Jet rocket cookstoves will shortly be presented to Faustine’s Nairobi charity in Nairobi . – our favourite worthy cause.
fireless-cookers egg-cooking-solar

What did you learn?
We figured out some of the peculiar aspects of a large solar cooking demo. These included what we needed to be doing to keep things safe and clean while operating heat emitting devices. Any kind of scary incident with our demo might have got us closed down on the spot. We took a lot of care.

Much of what we pioneered here can be replicated, at other events and maybe  at the `Green Gathering 2017′ if we get invited back.

What was the response from Visitors?
All in all the reaction was very positive. People were keen to learn – many were aware of solar cooking and some had even seen or made a solar cooker – with variable results reported from these experiments – mostly poor. Very few had encountered a manufactured solar cooker. In this context our display was eye opening. Some of our cooker types had never been demonstrated in the UK before.


People understood the global issues that solar cookers can help with – indoor air pollution, reducing deforestation and using free solar energy instead of charcoal, wood or fossil fuel. When asked about the number of people cooking on firewood most people far under-estimated the World Health Organisations 3 billion figure.

Visitors mostly ‘got’ the concept of integrated cooking which combines improved biomass cookstoves, fireless cookers and solar cookers  – allowing 24 hour cooking using no fossil fuel and minimal wood fuel. The question ‘I want to eat when the sun isn’t shining’ didn’t arise.

Far too many negative views were expressed about solar cooking in the UK. My favourite was ‘Its OK for Africa, but it wouldn’t work here…… ‘ as i pulled out a sizzling tray of frying onions / popping mustard seeds….., defensively they followed with ‘well it wouldn’t work in Blackburn!’. Perhaps they’re right?, I don’t know for sure (yet!). It was great to get the opportunity to challenge these assumptions directly, its what we at SLiCK have set out to do.

What would you do better
This was an outreach event and it was met with a lot of enthusiasm. Our event at the Green Gathering ’16  was probably the biggest solar cooking demo in europe this summer. We’re still figuring it out. SLiCK is self-resourced and this sets the scale of what’s possible. We would certainly like to bring some more cookers types on site and develop both the cooking aspect and the learning part. There are sure to be plenty of ideas leading from this event for a fantastic SLiCK Solar Cooking roadshow in 2017. Maybe we we’ll see you at one of them?

Author: Stewart MacLachlan – SLiCK Solar Stove

Join the discussion on the Facebook group Solar Cooking UK