These pictures show the homemade steam injection system that I use for bread
baking.
The system is basically a stovetop pressure cooker that has been modified
to send steam directly into the oven. To build the system, I bought a pressure
cooker at a flea market, drilled a hole in the lid, and attached a piece
of braided water line to the lid using a plumbing fitting. The flexible braided
line is crudely jammed into a piece of copper tubing, which in turn is routed
into the oven vent in the rear of the oven. Though the pictures don't show
this last step, I had to drill a hole in the vent tube in the back of the
oven, and then jam the copper tubing in as far as it would go. This last
step is much easier if you have the "old fashioned" kind of electric stoves,
since those generally have the oven vent right on the stovetop underneath
one of the burners.
In case it's not obvious how the system functions, I simply boil water in
the pressure cooker before putting dough in to bake. With the pot lid on,
the steam is forced out of the pot and into the oven. This provides a pretty
generous supply of fresh steam to the baking bread. I generally have the
steam going for 10 to 15 minutes after putting the dough into the oven. Messing
around with the pressure cooker in this way may initially seem a little bit
dangerous, but in reality, there is very little actual pressure involved,
since there is an free path for the steam to vent through. Furthermore, I
have retained the pot's original pressure limiting/relief valves. So pressure
is not a concern, but the heat of the steam is still something to be very
careful with; While the bread is baking, there is a good deal of steam escaping
from the oven, and care must be taken to avoid burns.
This system produces superb bread crusts. Pictures can be found elsewhere on this site.
(Click on an image to enlarge)