28" homebrew cast oven in walled enclosure Belgium

[Petter]

I got small pieces comming loose in the dome where there were casting defects. Most likeky during cooling since no pieces were found when cooking. It occured during full-fire #3-5 and I have not noticed any further degradation.

[Kvanbael]

Good tip kvanbael! Where are you located?

Sint-Laureins, between Brughes and Ghent.

[Kris S]

keep very thin timber at hand. The fire responds so much quicker to it. Even more if you preheat it in the entrance.

Good tip kvanbael! Where are you located?

[Kris S]

mmn, thats bad news indeed....., can you tel if your cracks form during heating or during cooling down afterwards?

but even so as long as its only a small chip here or there (and they dont fal in the food) i don't think the structural integrity of your dome is in any danger.... is there smoke leaking?

The cracks were there already from one of the last curing fires. They don't bother me, but after the pizza party I saw the missing chunk and the loose one. The oven floor did reach temps over 500 C though, so maybe that's a factor...

Can't see any smoke leaking because the dome is enclosed in a house.

Nobody else had small chips coming loose on the inside of a homebrew cast???

[Kvanbael]

Yesterday it was indeed pizza-party-weather (we had 15 ppl over). Your pictures look great! I hope the dome holds up.

my 2c on pizza baking:
Excess of flour will indeed burn black. Wipe and-or blow it to the side every few pizzas.
Btw: a wooden peel slides with less flour.

keep very thin timber at hand. The fire responds so much quicker to it. Even more if you preheat it in the entrance.

[Johannes]

mmn, thats bad news indeed....., can you tel if your cracks form during heating or during cooling down afterwards?

but even so as long as its only a small chip here or there (and they dont fal in the food) i don't think the structural integrity of your dome is in any danger.... is there smoke leaking?

[Kris S]

Now here’s a less pleasant thing to report: I noticed a small chunk of the dome is coming loose, and a bit higher up it appears a small piece has already fallen out!

Should I panic? I do remember after my casting that other users posts of their casting process looked more wet, my homebrew was a bit on the dry side.

Patching up is futile I think, I probably wont even be able to reach as well.

Any input greatly appreciated!

[Kris S]

Hello again! So we had another pizza party, this time we cooked 24.
Overall all went well, still learning to get better at Neapolitan style pizza making . (couldn’t get semolina flour this time)

I’m getting better at judging the ideal floor temp (and position for the pizza), I find anywhere between +/- 375 -450 °C (+/- 700 – 840 °F). higher and the dough/flour immediately burns black which tastes horribly bitter.
Fire management also getting a little better, learning the importance of having lots of flames going to cook the toppings in the same time it takes the floor to cook the dough. Having and maintaining this good floor / flame equilibrium is still somewhat difficult for me to keep going for a long time, in the end my floor was a little too hot and I had a little too few flames so the tomato sauce and toppings were not quite 100% cooked, but the dough was ready, so I take the pizzas out.

I had prepared 33 dough balls with a 24hr proof, there were 9 left, so without thinking too much I put the balls in plastic bags and straight to the freezer. The morning after we decided to invite some other friends for pizza again at noon because we still had some toppings and stuff left, so I took them out of the fridge in the morning to quickly thaw at room temp. not ideal because it’s better to let them slowly defrost overnight in the fridge I guess). Once thawed I did a little experiment and re balled 5 and let the other 4 flat and irregular. Should not have re balled them because it took a good 2 hours for them to flatten enough in order to stretch a good bottom. The ones id didn’t ball again were actually good enough to shape the moment they were at room temp.

These are some pics of the pizzas with the reballed dough from day 2 with left over toppings, they were still somewhat difficult to stretch, so a little smaller and floor / flame balance was not quite right, but they were delicious!

[david s]

While on semolina, you can also use it to test floor temp. A good party trick that I don’t bother with these days. You cast a small amount (about 1/3 tsp) onto the centre of the clean floor. It should suddenly turn black after 3 seconds. 2 secs = too hot, 4 secs= not hot enough. The floor is always too hot for the first pizza, so I simply cook the first one or two pizzas half in the entry where it’s cooler.

[UtahBeehiver]

Sometimes the floor just needs a little recharging after a number of pizzas. Rake the coals back over the cooking area, have a beer, then move coals back to side. Blow off ash and on your way again. plus the recharge burns off any spillage. I also use a length of 3/8" SS tubing for my blowpipe. Tape or foam the mouth end since it is really easy to chip a tooth. Some repurposers have use an old golf club shaft.

[Kris S]

I'll try the semolina next time! happy to learn and improve.

After shoving the fire aside, I clean the floor by first brushing the ashes away, and then mopping with a well wrung wet cloth on my turning peel.

So, yes, I think we use too much flour (it's not ashes on the floor).

[david s]

get yourself a length of pipe to use as a blowpipe to clear the ash for the first pizza and maybe between pizzas if needed. Just remember to blow, not suck. Sounds like you might be using a bit too much flour. About a 1/4 tsp of semolina on the peel makes the base slide around like it's on ball bearings.

[Kris S]

Here’s my report on the little pizza try out (11 pizza’s) we did yesterday for the big one (30 pizza’s) in 2 weeks time.

First off I’m really pleased with the oven temperature performance compared to the previous firings (this is the 4^th or 5^th i think): I see a noticeable improvement over the 2^nd firing:

Then:
45 mins: dome starting to clear
90 mins: dome completely clear
18 hours after firing (this morning) floor temp 80°C - 176 F

Now:
<30 mins: dome starting to clear
60 mins: dome completely clear
80 mins: floor temp everywhere +400°C
12 hours after fire out floor temp 160°C – 320 F (uninsulated door)

I guess this is due to 2 factors: the oven drying out more with each firing (as I heard on here), and me firing the oven a little more ‘aggressive’: whereas before I would start with a mini fire, slowly building up, I now loaded more wood to begin an built up a big fire asap. Happy to report no new cracks on first sighting.


Made 11 dough balls by hand the evening before and proofed at room temp for 22 hrs:
Water: 987g
Flour: 1763g (1000g tipo 00 flour and 763g regular flour because that was all I had)
Salt: 39g
Yeast: 0.55g

à Good dough, half the battle won

Lessons learned from cooking:

This time I created a much bigger flaming fire going at the side when cooking the pizza’s.
The first pizza we threw in immediately created a big grey smoke, this was probably the flour instantly burning, the floor was maybe a little hot at +430°C - +800F. seeing the smoke we feared it would be turned into charcoal immediately but it turned out great and was done in about 60 – 90 seconds I think, didn’t time.

I kept the bigger fire going all through the next 10 pizza’s by regularly loading wood, and as a result the floor temp constantly stayed about at around 400°C - 750F. the side of the pizza facing the fire was more like 430°C - 800F and the other side about 400°C - +750F.

Last time I was struggling to keep the floor at 350°C – 660F

à I feel like 400°C instead of 350°C results in better pizza making.

Other thing I learned is how little tomato sauce and toppings you need, very easy to overload and have a soggy middle.

Also maybe the underside of the pizza’s or the peel were a bit too floured, because after 5 pizza’s the floor was kinda dirty black of burned flour I think, giving a bitter taste. After cleaning it was better again.

à do you guys regularly have to sweep and clean the floor in between a few pizzas too?

I was so focused on everything I forgot to take any pictures

[Kris S]

Your oven looks great, and 180°C after 24 hrs is really good!

I gladly accept your offer, will pm you!

[Johannes]

hi Kris,

Mechelen is not really near, but i have friends there i'l probably visit next month.... if you want i can drop it of, just pm me,

Thanks for the tips, i have noticed the same thing, i have done pizza for 8ppl 2 times now, i did flamkuchen for 6... also baked sourdough bread and siu yuk (kantonese crispy pork belly) in the oven, works verry wel... ik have a crack in the entrance, but none in the dome itself...so far :-)
this is my oven;


its an oval shaped (85cm/120cm innside) flatend dome... firebrick but with a coating of vermiculite concrete on top, then, the entire enclosure was filled with a mix of vermiculite and argex (expanded clay)... the supports for the stone and the doorhandle i forged myself, everything was made from repurposed materials (the firebricks cam out an old bakery oven)
i had her up to 550°c and after 24h it still had 180°.... she's lager than a usual pizza oven, because i like to bake bread, and would like to do pig roasts in her.