Low temperatures

I made this sourdough last weekend and had a problem with room temperature.  It was unseasonably cold outside - close to zero. In the kitchen it was only about 18 degrees.

As a result, the dough really wasn't rising well. I ended up adding dried yeast, as well as moving it to the warmest place in the house (the clothes drying cupboard which is 26 degrees) to give it some oomph.

One of the loaves turned out very well as a result, despite I forgot to score the loaf before putting it into the oven.

The other loaf was made in a breadform and for some reason the crust turned out too hard and tough.

I loosely followed this recipe - although the bread tasted a little too salty - so either it uses too much salt, or I added too much since I don't have a very accurate scale.