:(

Francis,

don't be disappointed. Many of us (well I'll confess I am thinking of myself) have baked inedible bricks when first experimenting with sourdough.

I had a few questions

When you say that you used 100% hydration, I presume that you mean that the starter was at 100% hydration (equal weights flour and water). Your dough I imagine was less than that overall? (To work out hydration, add up all of the water (including that in the starter), divide by the total flour weight (Add up all the flour including that in the starter).

The usual reason for disappointing first loaves is that starters haven't come to full activity yet. How long has your starter been going? You refreshed your starter 12 hours before baking. What did it look like at that time (an active starter will have doubled in volume, have lots of tiny bubbles below the surface and a layer of froth on top)? (What temperature did you have your starter and dough at?)

Did your dough rise at all during prooving? How long did you leave it?
For the first rise I am increasingly using Dan Lepard's technique to know when to shape the loaf. That is - every hour or so after the dough is mixed slash the surface of the dough with a very sharp knife or razor blade. You should see lots of tiny bubbles below the surface when the dough is ready. With an active starter and a warm room that might be after 3 hours, with an inactive starter and/or a cold room it might be 5 or 6 hours or even longer.

Did you have any oven spring at all? (Did the loaf increase in size in the oven)?

Don't lose heart- you will make beautiful bread if you stick with this!

cheers
Dom

Francis,

couple of things,

you mentioned that your starter had bubbles - had it increased in volume as well? (How long has your starter been going?)

in terms of 'hydration' there are differing opinions as to what you should aim for. You can certainly make nice bread with lower proportions of water. My own experience has been that loaves with higher proportions of water have greater oven spring and more open texture.
So one thing that you could try would be to increase the amount of water in your dough (or decrease the amount of flour). For example if you were to decrease the amount of flour to 500g, that would give you a dough with 60% water content. You can increase this fairly easily up to 68% (which is where I most often have my dough, for example by increasing the water to 300g (ie 500g flour, 300g water, 250g starter)
As you increase the proportion of water in the dough you will find it stickier and harder to handle. Resist the temptation to add a whole lot of extra flour if you can.
Instead you could try aiming for short repeated kneads on an oiled surface(have a look at [url]http://www.sourdough.com.au/phpBB/viewtopic.php?t=46[/url] for a description of this)

If your loaf 'degasses' when you are trying to transfer it into the oven it will collapse and then fail to rise as much as you would like. Rub your cloth well with flour beforehand (ideally rye or rice flour) to try to prevent this.

hope this helps
cheers
Dom

Francis, I think your initial problem may have been the fact that your dough hydration was only around 42%, this is quite low and does take some experience to work with.
Most dough hydrations are between about 60% to 70%, some lower some higher. I think if you initially aim for around 62% you will get some better results. Then when you get the feel of that you can start to work with 68-70% . Dom is a great guide for these higher hydration doughs and will not lead you astray.

Francis,

starters can be fussy creatures. Sometimes when their favourite food is changed on them they have a little hissy fit and go into hibernation. So the drop in activity that you saw with change in flour may represent the starter 'reacting' to the change.
However starters like the rest of us can grow accustomed to changes in our environment, particularly if those changes are made gradually.
For example, if you detect a drop in activity with a change in flour your options are to refresh with the new flour for a few days (or longer) to see if activity returns. If there is some activity in the starter with the new flour it may be worth doing this.
Alternatively if there is not much activity at all, you could try adding small quantities of the new flour as well as your usual flour. Then you could try gradually increasing the proportion of the new flour until it is all the new flour and the starter is happy.

But I would suggest trying one thing at a time.
If your starter is happy and active with light rye flour, then keep going with that and try increasing the hydration first. Lets see if that makes a difference.
(By the way, light rye flour is perfect for dusting your lining cloths with. Don't be stingy, rub lots in, and the dough will not stick!!)

good luck!!
cheers
Dom

Ah, now that's looking good, nice crumb structure with holes.
What are you baking on, the bottom of the loaf looks very pale?