On 2006-01-19, Bob (this one) > wrote:
> Randall Nortman wrote:
>> On 2006-01-18, Bob (this one) > wrote:
>>
>>>Who subscribes to rec.food.baking? Are you a professional? Are you a guy
>>>who likes to bake on weekends? Are you a mother who needs to bake for a
>>>family? Hobby? Work? Hate it but have to? Love it but not enough time?
>>>
>>>Who are you? What kinds of information are you seeking?
>>
>>
>> "Serious amateur" cook and baker (except I don't take the "serious"
>> part too seriously). W.r.t. baking, it is mostly bread, mostly
>> whole-grain, mostly sourdough, though occasionally I use a little
>> white flour and/or some yeast. I have my own grain mill and bake with
>> various grains. I built a steam injection system for my home oven
>> (which I'm am currently in the process of upgrading by replacing
>> copper tubing with stainless steel and silicone).
>
> I'd be interested in hearing more about this. What kind of oven? How
> does your injections system work? Hardware?
[...]

The oven is a very cheap, low-end electric GE model, about 25 years
old. I got the idea from newsgroups -- search for "pressure cooker
steam injection" on Google groups, in this group plus
alt.bread.recipes, rec.food.sourdough, and rec.food.equipment (I
forget where I saw it). The idea is that you boil water on the
stovetop in a pressure cooker, and direct the steam into the oven via
heat-resistant tubing of some sort. You need to tap a pipe fitting
into the pressure cooker lid and find a way into the oven -- all
residential ovens are vented in some way, and that's the first place
to look. In my case, the vent is underneath one of the back burners.
It's a tight squeeze, but I managed to route some copper tubing
through there and into the oven. My current problem is that copper
tubing is actually only rated for up to 400F -- it doesn't melt when
it gets hotter, but the end that goes into the oven is getting quite
corroded now. I am going to replace it with a short length of
stainless steel tubing (expensive, but takes high heat and doesn't
corrode) for the part that's actually in the oven, and then use a
length of high-temp silicone (food-safe, plasticizer-free, rated up to
500F) to connect the boiler to the stainless tubing. The stainless
steel will then stay in my oven all the time, even when I'm not doing
bread, which will be much more convenient than my current system,
which involves installing and removing the copper tubing every time I
bake bread. When I finish this project, perhaps I'll post pictures
and details.

The final results depend on the strength of the stovetop burners. My
stovetop is cheap electric, and can't boil water as fast as I'd like.
I don't get the intense burst of steam that you'd get in a commercial
combi oven, but I do get much more than tricks like setting a pan of
water in the oven. I can keep the steam going as long as I'd like
(usually 10-15 minutes, until oven spring is totally done), and it
does get plenty steamy in there -- I can see steam rising from the
gaps in the oven door seal (remember, this is a cheap 25-year old
oven) almost immediately after I close the door, and I definitely need
to stand back for a moment when I open the door with the steam on.
The bread also cooks faster, presumably because wet air transfers heat
to the dough more quickly than dry air, or maybe because the air
movement created by the jet of steam coming out of the end of the pipe
turns my oven into a pseudo-convection oven.

Please note that all of the above is potentially dangerous and will
void any warranties within 100 yards. I'm not advising anybody to do
it.

When I have a chance to build or renovate a new kitchen, I've got my
eye on the Gaggenau residential combi oven. Expensive, but much
better than this mad scientist contraption I've currently got going.
I think KitchenAid just came out with one as well.

--
Randall