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)
 
 picture of the back of the oven top of stove top of pressure cooker lid underside of pressure cooker lid