Wood-fired Pizza Oven Experiment
February 26, 2012
We really like pizza baked in a wood-fired oven and we've been looking around at some design ideas for making an outdoor pizza oven. One low-cost option I came across is the KettlePizza, which is just an insert for a Weber grill that looks like this:
It's not quite what we had in mind but it's interesting as a low-cost and highly-mobile option. I especially like the highly-mobile part because I can see advantages to relocating it depending on wind conditions so that it's downwind of wherever we'd be eating. I also like the ability to watch the pizza bake, which is an advantage of having an oven with an opening like this. I realized I could make an approximation of the KettlePiza with our little 14" grill and materials I had on-hand so as an experiment, I cut a 3" x 30" strip of 1/8" aluminum and bent it into a semicircle to fit into the grill, leaving an opening just wide enough for a cast iron griddle to fit through. Aluminum melts at 1200 degrees F so it's not suitable for use in direct contact with burning coals but it should be fine when placed well above them.
I lit the grill in my usual way with a sheet of crumpled newspaper in the bottom of a starter chimney. No petroleum-based charcoal starter please! Once it was going I put some chunks of cherry wood on top in hopes of infusing the pizza with some wood-fired character.
I set the aluminum semicircle onto the grill and then added the lid, and set the cast iron griddle over the coals. I monitored the temperature with an infrared thermometer, trying to aim it at the griddle and not at the coals below.
Most wood-fired pizza ovens bake at around 700 degrees, which seems very hot but it supposedly cooks the pizza in only a minute or so. Once the interior temperature reached about 700 degrees I pulled the griddle out with a gloved hand, slid the pizza on, and popped it back into the oven.
It took about 2 minutes for the cheese to melt on top. This seemed a bit long compared to what I'd read about cooking pizzas in 30-60 seconds in an oven like this. The end result was pretty good on top but badly scorched on the bottom. Looks like the griddle was too hot!
Fortunately we had prepared two small pizzas so I had a second chance. I pulled the griddle out and set it on a snow bank, monitoring with the IR thermometer until it was down around 250 degrees. The I put on the second pizza and popped it back into the oven. It took longer to bake, about 4 minutes, and while it baked I kept lifting it up with a metal spatula and peeking underneath to make sure it was not burning. The end result was decent, nicely melted on top and just light brown on the bottom. Definitely an edible pizza, not outstanding but good, with some wood smoke flavor from the cherry chunks. Due to the longer baking time it didn't quite have that flash-baked character that the first one had, but avoiding the scorched bottom was a definite plus. Nobody likes a scorched bottom!
Okay, lessons learned: the cherry chunks made too much smoke, which was annoying and made the pizza taste more smoky than we'd like. And 700 degrees is too hot for the griddle but 250 is not hot enough. Also it was a bit breezy and I think that reduced the oven temperature over the pizza so it took too long to bake. Next time we'll skip the wood chunks, heat the griddle to around 400 degrees, and try to block any breeze from blowing directly into the oven opening.
February 28, 2012
This time we used just charcoal, no wood chunks, and preheated the oven to over 600 degrees. Then we removed the griddle and monitored it with the infrared thermometer until it had cooled to about 400 degrees before sliding the pizza onto it and returning it to the oven.
This worked a lot better, with very little smoke and the crust puffed up nicely without scorching on the bottom but we had to watch it very closely and we pulled it out as it was starting to get brown. The pizza came out pretty good, but the toppings weren't browned as much as we'd like and it was not a lot different than one baked in an ordinary oven. The crust was well cooked but didn't have that crunch that we like from wood-fired pizza ovens, even though it was fairly brown on the bottom. So it seems we have still too much heat on the bottom (cooking too fast) and not enough on the top (cooking too slowly).
March 10, 2012
We need to get the griddle hotter but at the same time to keep its temperature from rising too fast when placed directly over the coals. So this time we tried using some scrap 4-inch bathroom tiles on the grate, setting the griddle on top of them. Hopefully this will let us get the griddle hotter but at a more stable temperature, without getting hot enough to scorch the bottom as we leave it in longer to cook the toppings more. We'll put the tiles over the coals as soon as we light the charcoal so that they can warm up gradually to avoid cracking from thermal shock.
This approach worked great! We cooled the griddle to about 500 degrees before placing the pizza on it, and we were able to leave it in longer (about 5 minutes) to get the cheese nice and melted on top but with the bottom just nicely toasted. The texture was great, one of the best pizzas we've had. We had friends over and were able to cook about 6 pizzas, and could have done a few more before the grill started cooling down.