Some experiments are born from necessity, others from unbound curiosity. Then, there are those born purely of heatstroke-induced insanity, or so it would seem when the idea first struck me. With forecasts hovering at a scorching 106 degrees and the sun pounding down without an ounce of mercy, I had to do something with all that heat. If I could fry vegan eggs on the sidewalk, bake cookies in a car, and cook lasagna in a mailbox, could I go bigger? Could I bake a whole pizza… On the roof?
Getting Baked
Sure, conventional ovens are reliable, fast, and hygienic. However, when the summer heat sets in, baking the entire earth itself, why waste more energy and jack up the temperature inside the house, too? Let nature do the heavy lifting, especially when the ambient heat is already intense enough to melt the soles off your sneakers.
While 106 degrees is impressive for a forecast, it isn’t even close to hot enough to bake a whole pizza from scratch. Professional pizza ovens can easily reach 900 degrees or more, while a home oven tops out around 500. If this was going to work, I was going to need to bring in the heavy artillery, in the form of cast iron.
Cooking Time 0:00
Heavy Metal Pizza Party
Did you think I was about to just toss a whole pie up there a la Breaking Bad? I was originally planning on using a sheet pan just to keep things clean, but then I realized my trusty cast iron skillet could do more than just contain the mess. While direct sunlight delivers a steady stream of radiant energy, a dark, sturdy cooking vessel can absorb and retain some of it.
It takes a 12-inch cast iron skillet to contain the average frozen pizza, which is what we’re working with here. It can’t have a rising crust or start from raw dough for this to work at all. A thin, already par-baked frozen pizza is the best candidate because we’re really reheating and finishing it, rather than asking the sun to perform the considerably more demanding task of baking raw dough from scratch. A prepared shelf-stable crust could work in a pinch, too, although I personally find most of them about as appetizing as cardboard. Flavor may be a secondary objective here, but it still counts.
Don’t Be Like Walter White in Breaking Bad
Sun-Kissed Skillet
By placing the empty skillet in direct, unobstructed sunlight, it can effectively preheat while the sun reaches its peak. The shingles underneath play an important role, too. A dark roof sitting in direct summer sunlight can become dramatically hotter than the surrounding air, effectively turning the entire surface into a giant solar collector.
I chose a reasonably flat, level section of roof with maximum sun exposure. A sloped roof might be more architecturally interesting, but it’s a terrible place to balance several pounds of screaming-hot cookware. If your skillet starts slowly migrating toward the gutter, the experiment has officially gone too far.
Once the skillet had spent some time soaking up the midday sun, I added the frozen pizza and covered it with a clear glass lid. Heat-safe plastic wrap would work as well, if you don’t have a matching set. The idea is to create a miniature greenhouse, allowing sunlight to pass through the clear cover, while the enclosed air and accumulated heat can’t escape as readily. It also provides a critical secondary function: keeping the flies off. Even rooftop pizza attracts freeloaders.
Cooking Time 0:50
Let There Be Light
Timing is crucial. I started the experiment around noon, when the sun was approaching its strongest point. A clear day is essential; clouds may not lower the air temperature much, but they can dramatically reduce the radiant energy reaching your setup. This is also where patience becomes mandatory. An oven can cook a pizza in minutes, while the sun will take hours.
After about an hour, the cheese had begun to glistening, starting to sweat under scrutiny. After 2 hours, it was reasonably liquefied. Given how notoriously difficult it is to melt vegan cheese to a reasonable degree, this marks a huge success. The crust, of course, remained pale as a ghost, but at least it looked dry, if rather floppy.
The roof itself reached over 170 degrees, and with the combination of direct sunlight, dark cast iron, and the greenhouse effect from the clear cover, the enclosed cooking environment likely climbed to around 200 degrees or more. That’s still nowhere near standard cooking temperatures, but it was enough to gradually heat the pizza through.
Cooking Time 1:55
Notes From the Field
A few things became very clear over the course of this ridiculous experiment:
- Peak sun matters. Start around noon and take advantage of the strongest sunlight between roughly 12 and 3 PM. Don’t expect the same results if you start late in the afternoon, even if it’s still brutally hot.
- Clouds are the enemy. This experiment depends on direct solar radiation, not simply hot air. Wait for the clearest day you can find.
- Flat is not optional. A level roof keeps the skillet where you put it. A pitched roof turns your solar oven into a potential pizza sled.
- Use a dark, heavy pan. Cast iron absorbs and retains heat far better than a lightweight, shiny baking sheet, making it much better suited to this slow solar bake.
- Give the skillet time to preheat. Put the empty pan out before adding the pizza, ideally for at least 1 hour, allowing it to absorb as much heat as possible before the pizza enters the picture.
- Keep it covered. The clear lid or plastic wrap traps heat and creates the greenhouse effect while keeping insects, dust, leaves, and other rooftop debris out of your lunch.
- Choose your pizza carefully. Thin crust and already par-baked are essential. Skip raw dough, rising crusts, deep dish, and anything heavily loaded with wet toppings. The sun has limits.
- Use an infrared thermometer. The weather forecast tells you the air temperature. The thermometer tells you what your pizza is actually dealing with. Check the roof, pan, and pizza itself periodically.
- Be patient. Commit somewhere between 2 – 3 hours for this project. Conditions will vary, so think of the clock as a guideline rather than a guarantee.
- Don’t leave it unattended. This is a heavy, hot piece of cookware sitting on a roof. Keep an eye on the setup, especially if there’s any wind, and only attempt the experiment somewhere you can safely access and where the surface can support you and the equipment.
- Protect yourself. Always use potholders, even after the lower-intensity preheating stage. That also means to apply sunscreen liberally, stay in the shade when you can, and drink plenty of water! Spend too much time out there with your pizza, and you’ll start cooking, too.
Nothing New Under The Sun
Unsurprisingly, this method will never produce the best pizza you’ve ever had. It won’t even produce the most acceptable pizza you’ve ever had. It will, however, give you an edible pizza-like substance, albeit completely lacking in structural integrity. Similar to the effect of tossing a day-old slice in the microwave for 30 seconds, but with a few hours of work and the risk of heat exhaustion, it’s objectively one of the least satisfying ways to prepare dinner.
At least I’m not one to be deterred by impracticality. If anything, the sheer absurdity of the whole concept is what made it so appealing. Once I got it into my head, I simply had to see the plan in action. What else am I supposed to do when it’s too hot to leave the house, after all? I’m sure my neighbors already think I’m a little strange, but crouching on the roof in the middle of a heatwave with a cast iron skillet and a camera probably didn’t do much to dispel that notion.
Maybe next heatwave, I’ll have a better idea, or at least one that doesn’t require explaining myself to the nice people living next door.