This is a work in progress about baking pizzas in gas-fired pizza ovens such as the ones
supplied by ALDI. Currently this is mainly a
list of extracts from my diary.
The ALDI oven appears to be a copy of other, more expensive ovens. Here ALDI on the left,
and a $1000 “Gasmate” model on the right:
The design is deeply flawed. In the configuration in which they're intended to be used, the
pizza stone is heated strongly from below, and pizzas tend to be burnt on the underside and
inadequately browned on the top:
I'm still working on a solutionworkaround, but the clear way to go is place the
stone higher in the oven. The other question is the temperature of the stone. I've bought
an infrared thermometer, and by experimentation it seems that a stone temperature of 280°
and an oven temperature of 320° gives good results if the pizza is placed on the top shelf.
The diary extracts
The following are blow-by-blow descriptions of how I experimented.
I've been working towards better pizzas for some time, and currently we're baking them in
individual electric “ovens”. They have the disadvantage that they're not much space between
the pan and the heating element:
We've learnt to avoid that particular problem, but this week ALDI had a gas-fired pizza oven in their weekly specials, and we heard from Nele Kömle that she
had bought one and was happy with the results. So off into town to buy one. It's a strange
device, and it seems that even the people who made the packaging didn't really understand:
Got round to assembling the pizza oven today. It wasn't as difficult as I have become
accustomed to with ALDI devices. But I'm left
wondering what they were smoking when they designed it:
My recollection, not helped by the extremely low signal-to-noise ratio on Google, is that a
pizza oven is flat with a ceramic base, the (wood) fire to one side and the flue on the
other. The hot gases from the fire go sideways to the flue, heating the ceramic base in the
process. You put the pizza on the base, which cooks the pizza from below, and the hot gases
cook it from above.
In this model, the ceramic base is square, and it's heated from below by the (surprisingly
strong) gas burner. But how do the gases go over the top of the pizza? It seems that this
is a recognized problem: the instructions, such as they are, don't tell you how warm to make
the oven, nor how long to cook the pizza, only (original punctuation):
Because the pizza stone sits directly above the burner it can get extremely hot. If you
are finding that your pizza bases are cooking too quickly or burning on the stone then the
first step is to turn the gas setting to low.
If you are still cooking the pizza's too quickly we recommend starting to cook the pizza's
on either of the two roasting racks first... We also recommend using pizza trays to cook
with.
Doesn't that fill you with confidence? Using a pizza tray (whatever that is) is contrary to
the idea of cooking it on a stone? How hot should the stone be? How hot the ambient
temperature? What use is the thermometer at all, especially since, like the
barbecue it's marked in obsolete
temperature units with Celsius added as
an afterthought:
How do you set 200°? There are 5 markers between the marked temperatures of 177° and 204°,
steps of 5.4° each, so the last mark before 204° is 198.6°. Why do people have to do this?
The thing is made in China and sold in Australia, both metric countries. What does this
have to do with the USA, just about the only country still
using Fahrenheit?
In any case, we'll see what happens. So far it doesn't look very promising, especially as
it can only do one pizza at a time.
Of course we had to eat pizza this evening to try
out our new pizza oven. The first issue is the way it's built: there are two shelves,
neither adjustable in height, and the lower one is so low that you can't access the stone if
it's present, so I removed it. And they've conveniently put an apparently useless shelf
underneath just on top of the gas cylinder, which makes it really difficult to insert the
cylinder or turn the tap on or off without kneeling down and scraping your knuckles:
How hot? Went looking on the web and found the usual vaguenesses, but also the suggestion
that pizza ovens run really hot, up to “800°” (i.e. 425°). Coincidentally that's the
highest temperature that my oven shows, so probably it should be really hot.
But conventional ovens don't heat the stone from below, so I was careful and started baking
when the thermometer showed 204°. A good thing, too. After an appropriate period of time,
the pizza looked like this from above:
That's clearly underdone. I took it out and put it on the top shelf, where it browned
nicely from above. Here's half the first pizza, which browned above, and the second one,
which didn't:
It was also uneven, probably reflecting the shape of the burner.
So: as I suspected, heating the stone directly in the flame is Just Plain Wrong. But maybe
there's hope yet: the first pizza browned nicely placed further up, so maybe that's where
the stone belongs. Clearly more experimentation is needed to work around the basic
deficiencies of the device. It's a good thing I have two months to try.
While at Pivot, took a look at their
pizza ovens. There was quite a nice brick one for a wood fire, laid out as I had expected:
fire one side of the pizza, flue on the other side. Price: about $3,600.
It looks prettier, but it has the same failings, it looks a little smaller at the top, and
it costs four times as much. As far as I can tell, both the stone and the shelves are
identical, and it even has the same knuckle-scraping shelf above the gas cylinder. What are
people thinking?
Our first experiments with
the ALDI pizza oven showed that the thing is
incorrectly designed, but also that it can reach temperatures significantly higher than the
250° of a typical household oven. Just the thing for tanduri chicken? Certainly worth trying.
It's not just the chicken that gets cooked in
the tandur, of course: there's also the
nan. In principle that's made the same way as a pizza,
between the hot gases and the ceramic side of the tandur.
How to do that in the pizza oven? Like a pizza, you'd think. That has the added advantage
that the cooking nan doesn't fall off to the bottom of the oven. But these things are hot,
and there's a considerable danger of injury or scorching if you do it wrong. In the end I
came to the conclusion to use two pizza stones (not the one supplied with the oven) and heat
them on the upper shelves, then to use them alternately on the top shelf while grilling the
meat on the middle shelf, with only a drip pan at the bottom:
How did it work? Not an unmitigated success. The first surprise was how quickly the oven
heated up without the bottom pan. Then getting the nan onto the stone proved less than
successful:
Apart from that, it was difficult keeping the oven warm once the drip pan was in place. A
clear disadvantage of the metal construction is that the oven cools down as soon as you open
the door, and it was difficult to keep the temperature above 250°. The nan didn't bake
well, so I tried the others in the electric pizza ovens, first warming the tray on the
stove:
It's not clear how much the style of cooking had to do with that. The nan just didn't rise,
and it doesn't look right. Probably time to review the nan recipe. On the positive side,
the chicken didn't come out too badly, though I think it would benefit from higher
temperatures. Clearly a lot of experimentation in the near future.
Another attempt to cook pizzas with the pizza oven today. My infrared thermometer
still hasn't arrived, so again I had to guess how hot the slab was. By the time the oven
temperature reached 204° (it's too leet to show 200°), the slab was so hot that I couldn't
leave the pizza on it long enough for the crust to brown. But at least I didn't burn them
too much this time.
I find my opinion confirmed: putting the stone at the bottom of the oven and heating from
underneath is Just Plain Wrong. Next time I'll put the round stones on the upper shelves
and see how that goes.
On the positive side, found a better way to put the pizze in the oven, without buying a
ridiculously expensive peel: put them on the underside of the metal pans for the electric
pizza ovens with a bit of maize flour to help them slide.
A few weeks back I bought an infrared thermometer on eBay, and today it finally arrived. The main purpose is to measure the temperature
of the pizza stone in the pizza oven, but of course that won't be for a while. In the
meantime I played around with it a bit.
One thing's clear: it's not the kind that you can stick into your ear and measure blood
temperature. I tried that and got a temperature of about 23°. But pointing it at hot and
cold objects show that it works, at least in principle. The trouble is that it's a spot
measurement, so the variation between -18° and -14° in the deep freezer, or 190° in the
corners of the oven to 210° in the middle, could be correct. Heating a frying pan gave
higher temperatures directly above the flame than in the corner. So it looks like it's
something I'm going to have to learn to understand.
Now I have my new infrared thermometer, it was time to try another pizza in the gas oven.
My hypothesis was that the stone should be placed higher in the oven, where the oven itself
is warmer, and the stone is not overheated by the flame at the bottom. But what's a good
temperature? Went looking on the web and found surprisingly little. I found two pages,
both of which confuse the issue by using
the Fahrenheit temperature scale.
This page goes into great detail about the theoretical background, and suggests what
I've already decided, that the pizza needs to be cooked higher in the oven. And it
describes using an infrared thermometer to measure the stone temperature. It suggests that
at the bottom of the oven, the stone will reach 360° (680°F) when the oven temperature is
290° (560°F), but it doesn't specify what temperature to aim for. It seems to be more a
plan for an experiment than a report on the results. It's a blog, so it's reasonable to
assume that he reported on the results elsewhere, but I didn't find them.
The other page is definitely a results page. It describes things in detail, actually
showing photos of the infrared thermometer in action—something that not even I thought of
doing: after all, it's just a reading. After 50 minutes, his stone was still only at 175°,
and it took him 90 minutes to get it to 240°. Then he started baking, but only because his
son wanted to eat. Once again no suggestion of what temperature he should be aiming for.
So: I heated the stones on the two upper shelves. It took about 30 minutes for the oven to
heat to a little over 300° (I must really replace that horrible guesswork
thermometer), by which time the upper stone was at 260° and the lower was at 240°. The
temperature in the oven dropped to about 270° when I opened it and put the pizze in, but
then went up to about 310° when I shut it—all this with the flame on full blast. After 10
minutes the upper pizza was through and nicely browned. On removing the pizze, the stone
temperatures had dropped to about 170°. The lower pizza was through and almost not browned
at all:
So: where do we go from here? Both bases were excellent, crispy but not burnt. So I'd say
that 250° is a reasonable temperature for the stone, and if I'm doing 2 pizze, I should move
the lower one to the top shelf for another couple of minutes.
One thing's abundantly clear: the design of the oven is Just Plain Wrong. That's only
ALDI's fault to the extent that the copied a
much more expensive, but equally badly designed oven.
