Ever wanted to have a professional steam oven at home? OK well... this isn't exactly that - but it does work!
All it took was a steam-cleaner, some copper tubing, and a reckless disregard for oven warranties. You too could ruin your oven have a semi-professional steam oven at home...
All joking aside... two very important notes:
- This really did work well and gave me full control of the steam generated during that important first bake phase
- This is a terrible idea from a health-and-safety perspective and you should definitely *not* do this yourself at home!
But just for posterity, here are the details...
First, why do you want steam?
Steam during the first minutes of a bake stops the crust from forming too quickly. This allows your loaves to reach their full potential in terms of oven spring. After the loaf has grown to its full potential, the steam is released and the crust then begins to harden and darken. If all done correctly, you're left with the beautiful blistered crust that is so emblematic of a delicious crusty loaf of sourdough.
Technical details
Steam cleaners can be picked up brand new for as little as around $30/£25 and most of them come with a nozzle that allows for adding different attachments. We're really just going to use the steam cleaner for what it's made for (sort-of)... producing steam. The only thing left to do it find a way to route this into the oven safely, and have it vent evenly on both sides. I was lucky in this case because I had an oven near to the ground, and I was able to get some small copper tubing to fit through the bottom of the door in such a way that the weathering fit around it and kept the oven pretty air-tight.
The copper tubing is just the cheap type you can pick up at your local home improvement store. In order to make it go to both sides of the oven, I used a "T-junction" to split the steam. The only other piece was an adapter (also sold right next to the T-junction pieces) that fit the steam cleaner on one end, and the copper tubing on the other.
Now in theory these pieces could have just been shoved together and they would have probably worked pretty well, but I wanted to make sure they were air/steam-tight. That was nice and easy to do with the help of a butane torch and bit of solder (meltable metal in wire form).
So as a quick review: The steam cleaner produces the steam and pushes it down it's hoze to the nozzle, where I had a copper adapter that connected the copper tubing. The copper tubing is nice and bendable so I had this positioned so that it turned straight up from the bottom of the oven where it entered between the oven door and the main unit. From there, it his a T-junction and the steam went both left and right, where it was adjusted to come out on both sides of the baking steel where the dough would soon be placed.
Baking Time
Just before I took my dough out of the banneton, I filled the steam cleaner up to maximum and pre-heated it. Then when I placed the dough in the oven, I closed the door and turned on the steam cleaner and locked it in the "on" position. I got lucky with my steam cleaner as it was able to produce steam steadily for about 10 minutes before it was out of water. Luckily - that's all I needed!
So... why the past-tense?
In the end, I had beautifully raised loaves with crunchy blistered crust, and I didn't have to use lava rocks or any other steam-generating technique, so... why am I writing most of this is the past-tense? Well... It may have been unrelated, but that oven burned out a heating element about a month later! I'm not sure my steam contraption was to blame, but I'm guessing it didn't help!
So if you are brave enough to give this a try (remember: I do NOT recommend this!) then please let me know as I'd love to hear if it works well for others!