Only a few days later, and I already have to update the post.
I’ve been doing some research into yeast and have come to the conclusion that I am using way too much yeast in this dough.
Small amounts of yeast will reproduce rapidly given the right stimulants. So, if I decrease the amount of yeast, but let the sponge work for longer (a few hours instead of 20 min) then the resulting yeast will be stronger, and I won’t need to use as much.
Some people seem to recommend using 1 tsp of yeast in a sponge to get the same effect of a normal 1 tbsp.
I am thinking 1 1/2 tsp, or 1/2 a tbsp instead. It’s a little more, but this should work. My plan is to make the sponge in the morning, let it grow all day, then make the dough in the evening and let it rise all night, then make the bread the next day.
A very medieval system.