Hot Rod Steam Injection
I couple years back, I picked up a used Italian made, electric utility oven, i’ve recently got around to hot rodding it with steam injection.I’ve come up with a pretty slick and effective steam solution, the parts list is quite simple, the heart of it being a piece of stainless steel hand rail. I purchased the exact length of handrail required, two ends, copper pipe and a stainless steel funnel that fits perfectly inside it. With the drill press, i made three rows of 5mm holes and one hole in each end piece.The mounting turned out to be quite slick and simple, the back pipe cap has a bolt mounted that fits tightly in a hole in the rear oven wall, the copper pipe fits tightly in the front cap hole and leads through a hole to the funnel.
The three rows of holes, are of course pointed upwards. By pouring a small amount of boiling water into the funnel, it produces an intense blast of steam as it flows down the hot copper pipe into the „hotrod“ injector tube.
My objective is to have all of the water turn to steam in a very short time, the trick is figuring out the optimal amount of water and angle of grade on the pipe.
So far, i’ve done four test bakes, the first two of which, i used far too much water. The bread though has been sporting a lovely shine.
One problem with this is that when the pipe gets piping hot, those tight fitting end pieces loosen up just enough to allow a slight drip of water, so this makes the dosing very important. During the last two bakes, I managed to keep this to a minimum. I have the idea to disassemble the injector, increase the mass by stuffing it full of heavy nuts&bolts or lengths of steel rods, the increased mass should give me the option to increase the water dosage somewhat. When i’m happy with that, i’ll take it apart again and have a friend weld the end caps on, that should put an end to possible dripping. Being that there are so many bargain priced used commercial pizza ovens on the market, i thought this might be of interest to folks wishing to take a step beyond the regular home oven.The baking chamber dimensions with pizza ovens are sometimes less than ideal, some are a little tight in the height department for bread baking. But the ovens are often well insulated and feature heating coils designed to bake pizzas lightening fast. Rigging up steam injection though is the real key to making them truly useful for bread baking. The oven that I rigged this up in has a 26cm chamber height, i’d rather that it was 23, but it’s turned out to be a pretty decent bread oven non the less.additional oven info& photos here 
bread from a test batch
Good steaming solution.
Reminds me of the old brick ovens in bakeries supplying sourdough bread to the local restaurant trade in old North Beach, San Francisco. A valve on the upper right of the oven's face piped water into a cast iron trough steaming the bake load. Worked a charm.
Suggested Design Items:
1.) Packing the steam distribution tube with stainless steel wool too limit steam-water spatter.
2.) Insert a valve below the feed cup will allow adjustment of the water flow to a near drip.
3.) Use food grade teflon tape to seal the pipe joint threads.
Wild-Yeast
Fooling with steam is a fine thing, I like your stainless steel wool idea. Water splatter is not an issue at present with my steam gizmo, however by sliding 4 or 5 steal rods into the tube to build mass as i plan to do, could well make for a splatter problem. Stuffing stainless steel wool into the remaining upper tube space could be an excellent solution, thanks for the idea. What sort of trades people use this stuff, If i knew it would of help in sourcing it.
The valve is also a good idea, presently, i pour the desired dosage of boiling water out of a tea cooker into a small metal cup then I pour it slowly into the funnel. I'm fooling with amounts between 100 and 150mm, Idealy i would like all of the water to evaporate as it lands in the tube. What I want to avoid is having a leftover pool of water there that slowly disappears during the last 2/3 of the bake off.
Yes brick ovens do well with manual steam injection, i worked on a large wood burner in canada for several years. It had a lava stone filled, shoebox sized iron container built flush into the bake chamber walls, one left, one right. Copper pipe led to front mounted brass funnels, it was a thrill to pour water down those funnels...kabuuusch steam galore. for monster brick oven photos check here
Use stainless steel scrubbing (scouring) pads available in hardware stores or on the internet.
Wild-Yeast
Nice setup. I am doing something similar with the small quarter sheet Cadco Convection oven. It has a vent tube that starts in the back of the oven compartment and ends at the rear top of the oven. I made up some copper pipe to have a line come around to the side of the oven, and a t connector. When I want steam, I open the pipe and spray steam in it from a small hand held steam generator ( the kind for steam cleaning ), and then close it up. When I want to vent it, I remove a stopper from the pipe. I prefer using steam to boiling water, because it takes a tremendous amount of energy to convert boiling water to steam. Since it is convection, I am turning off the oven when I steam and letting the temp drift down a few minutes, otherwise I am afraid the convection will offset the steam. Also, I have read that if you oversteam the loaf, it will get dense, and so I am still working on timing and how much steam.
What your doing there also sounds interesting, have you taken any photos?
Yes over doing the steam is also not good. What i'm trying to emulate is the plumbed in steam injection typically used in quality deck ovens. They have the advantage though of generating steam on demand allowing for a preloading chamber steaming and then again immediately after loading. This is i believe is not possible with a low mass gizmo such as i'm playing with. It was possible on the multi ton brick oven. However what i want to accomplish is to generate sufficient steam to nicely cover the loaves with vapour with in seconds of loading and closing the oven door. It always a play with the dosage and duration to retain it, the loaf shape, leavening, slashing, dough characteristics and the amount of bread that's being stuffed into the oven , all come into play. It all serves to keep this recreation interesting.
cheers
I also use a home type steam cleaner to inject steam into the oven. My blog post is here. My Amazon review has become buried in a haystack of umpty something other reviews. If you want to read it, go here.
cheers,
gary
Thank's for posting that Gary, i read your review and blog post, looks good. I have a second oven in the bake room, a larger one, It has manual steam, stock from the factory but I find it to be a little inadequate. It would be a fairly simple matter to creat an access port to stick a steamer nozzel into. With this, i could do a thorough preloading steam application and then repeat post loading......I think I'll have to give this a go.
dang...now you have me off in a new direction ording another gizma gig.
cheers daniel
Do you remember the any of the names of these bakeries?
For baking bread I have great success with spraying the loaves themselves with water rather than steaming the oven.
I remember one that was a block from Joe's brother's place, DiMaggio's Fish Grotto on Jefferson but don't for the life of me remember the name. I think a parking lot is there now...,
Wild-Yeast
gary.turner: you might find a rubber stopper to be a more elegant solution for plugging your oven's vent hole than a wadded-up towel: http://www.mcmaster.com/#rubber-stoppers/=tsnx86
Wadded? Never! I use a neatly folded, wet tea towel, I'll have you know. :P
Wouldn't the stopper need to be silicone rather rubber? High temps and rubber might get a bit stinky.
cheers,
gary
Boudin has a bakery at 160 Jefferson street. Could that be it?
silicone o-rings ought to help with the joint leaks. Most common found in coffee makers (in case you have one junked lying around.) Also a good source for a short length of silicone tube should you need that also. Heck, you could even rig a small coffee maker to boil your water draining into the oven. Actually not a bad idea when I think about it. Remove the funnel, connect to the filter part. Then you would have automatic delivery of hot water for the first few minutes.
Shiny crust is what I miss, now that I no longer have my Korean Steam oven. It put out minutes of steam to the point of seeing a dribble run down the wall of the oven towards the oven floor. Never made it though. To stop the steam, easy enough, remove the water source and quickly vent the oven opening the door.