Too Much Steam?

for several reasons:

1. When my new electric oven seemed to heat up slowly last year, I timed how long it took to hit milestone temps.  19 minutes to 500dF, I just checked my notes.  I called up GE to verify whether this was normal and was told that it was.
2. Just because the air inside the oven may hit 500dF, doesn't mean the baking deck does.  I want that deck to absorb the heat for a period of time in order to provide a thermal mass that retains heat and will not cool down much when the cool dough is loaded or the oven door is opened.
3. In order to pre-steam the oven it will take a few minutes of introducing a sufficient source of steam to fill the box.

Even with steam my oven returns to the temp set, although it will take several minutes into the bake.

Our new oven is split between an upper, much smaller box, and the lower, much larger box.  We bought it a year ago, one year into my home baking interest, to avoid having to jockey the baking deck tiles in and out of the previous single box oven.

Clearly the smaller box heats up much much faster.  It isn't even a race.  So box size certainly is a major factor in reaching the ambient air temp inside the oven.  My notes say that the bigger box reaches 425dF in ~14.5 minutes.  The smaller box reaches 400dF in six minutes.  So yes, box size is certainly a consideration.

As far as baking surface goes.  Once the air inside the oven hits desired temp. it does not mean that whatever is inside of the oven has, assuming that one places the object inside the cold oven when it is fired up.  Otherwise that 12 pound turkey would be cooked by the time the oven reached full temp.  Same is true with the deck tiles.  Their surface is affected by the air temp, but in order to heat them and their entire density up fully, it will take time for the entire tile to reach oven temp.  With the employment of deck tiles, anything short of that and one will likely be baking the dough sitting on them at a disadvantage, certainly on the underside of the dough.  To me, that translates to an underbaked product.  If one loads the dough directly onto a wire oven rack, I agree with you, the additional time that the oven is on will be negligible.  So in this case, I'm addressing using a baking deck.

Also, the deck tile helps to keep the ambient temperature in the oven from dropping too quickly, just as with your example of the electric element providing some thermal mass, as the tile will continue to radiate heat into the box between the oven cycling on and off.

When I turn the oven off after a bake, the box stays quite hot for an extraordinarily long time with the baking tiles inside.  Before I did home baking, the oven would cool down in a significantly faster time frame.

I don't use a Dutch Oven, just rely on baking everything directly on the tiles.  I'll preheat the oven to maybe 15 degrees more than the desired baking temperature and then reset the thermostat upon the dough being loaded.  My baking temp is set between ~460 and 500 depending on what I am baking, usually ~475 or 480.  I like a dark baked bread - always baguettes or batards and usually two or three bakes a week, and can't recall a single instance where the underside of the loaf came out burned - unless I was completely negligent.

Now, I'm not saying that your experience is/should be the same as mine, I can only report back on my own first hand experiences as well as the guidance of many TFL bakers on this site.  And that's part of what I cherish about this site, so many voices sharing their own experiences and helping us all to get a better understanding of the variables.  Way more that one can ever get out of a few books on a bookshelf. 

of Pandora's Box being opened!

Let me see whether I can give you an adequate answer, again keeping in mind that I am no authority, just another participant here with some experience.

1.  How much steam is needed for a baguette? how long should it be applied? any criterion for telling when to stop?

 Generally there should be "sufficient steam".  That's a hard one to quantify, because as you saw above, there are different size ovens and a smaller one will require less steam overall to fill the cavity.  As I replied above - for my money's worth:

Adding one Sylvia's steaming towel at ~ the 1/2 hour mark for the final 15 minutes of pre-heat.  That's one rolled up terry towel in a pan of hot water.  After loading my dough I pour 2 cups of near boiling water into a pan of preheated lava rocks.  Closing the oven door, the oven temp is reset to ensure that it will re-fire to the correct baking temp.  ~12-13 minutes later I open the door to terminate the steaming by removing the towel pan and then rotate the dough on the oven deck.  By this time all of the water in the lava rock pan has steamed off.  

The criterion is satisfying the goal of what we use steam.  And that is to delay the gelatinization of the crust, by keeping the surface of the dough cooler and somewhat moist long enough for oven spring to complete, but not so long that it inhibits the crust from properly setting and baking.

2.  I understand now that the oven temp drops when steamed, and then rises again.  any recommendation as for the optimal temp vs. time variation throughout the baking?

 Differing formulae require differing baking requirements.  Go with the author's recommendations.  They have hopefully tested their creations enough times to be confident in both the duration of the entire bake as well as the recommended oven temperature.  Now, I like a dark baked bread, others like a lightly baked crust.  Therefore the bake time will vary for me vs. those who like it lighter colored.

3.   How do you decide that the baguette is ready? should the inside be somewhat moist?

See above.  But a general rule of thumb is that the inside of the baguette should reach 205dF to 210dF.  I never temp. my breads, because after a while I just know what I'm looking for.  There also is the "thump test" whereby one thumps the underside of the bread with a fist and listens to hear whether there is a hollow sound indicating "doneness".  With a baguette's thinness, this may be unreliable and perhaps damage an under baked bread.

The inside will be moist under two conditions - an undercooked baguette that did not complete its baking cycle.  If it is not undercooked then it will be moist if you cut into it too soon and have not given the bread a chance to shed any additional moisture that will dry out over the first hour - or longer depending on the hydration of the dough as well as the types of flours used.

No simple answers as there are so many variables.  Part of the frustration and the fun.  My suggestion is to find a formula you think that you will like and try to duplicate it.  Start simple, move toward complex, don't get frustrated, change one variable at a time to isolate the errors and improvements.  Time, mistakes and experience are the best teachers.

alan

The towel, if you'll glance again above at what I wrote, actually sits in its own separate pan of water, rather than on the lava rocks.  Eventually, the towel will scorch a little from the exposure in the oven, but my one dedicated terry towel still a lot of life left to it for this purpose.  

A search on TFL for "Sylvia's steaming towel" yields a pretty fair number of references to it from others aside from myself.  That's how I caught on...

alan

Mega Steam, in a pan of water provide much more steam much faster than a pan of water.  I won't go into why  for you but it all has to do with surface area and how water actually flashes into steam.  It is just science that bores most folks

Happy  baking