Sourverdict

So the verdict is: not yucky.

The bread was a little undercooked, in the end, but quite moist and tasty. Mildly salty, difficult to cut, densish, tough on molars.

I quite liked it. The girls gave it a literal thumbs-up. the dutch and non-dutch loaves differed pretty much only in crust colour; I'm not sure that, with our oven, the dutch part is really necessary.

A lot of work, odour, and inconvenience, though.  I'm not sure yet how that balances against the little plastic packet of the industrial yeast.