According to a post on the Fresh Loaf web site:
the recipe is very simple: 33 kg of flour, 22 litres (i.e. 22 kg) of water and half a bucket (maybe 5 litres?) of starter.Amazing to see someone work with that much dough.
What's also interesting to me is how this recipe matches up with the 1-2-3 recipe for sourdough, which is, by weight:
3 parts flour
2 parts water
1 part liquid starter (100% hydration)
And of course salt, which will be around 2% (well, 1.8 - 2.2% to be more exact) of the weight of the flour.
Well, what is liquid starter @ 100% hydration? Simply, an active sourdough culture that has been maintained at 1:1 flour-to-water, by weight.
1:1 flour-water starter is different if you go by volume:
1 cup bread flour (using fluff-dip-knifescrape measuring technique) weighs about 132g
1 cup water @ room temp weighs about 236g
This results in a starter that has a 178% hydration!