my first focaccia

[jacker]

Biga: 1 gram active dry yeast 200 grams water 400 grams bread flour , 
Dough: 440 grams cold water, 430 grams apflour

i need some advice or any recommended video how to shape focassia high hryd dough

i believe its underproof

20hr cold proof
1.5hr at room temp
dimple and proof futher  for 30min before baking

[Ischia]

Looks pretty good. I think you need more time proofing in the pan at room temp. When the dough is room temp it is easy to stretch to the pan shape, then let it fully rise in the oiled pan, then dimple with more oil just before baking. 

Why biga and not a direct dough at 77%?