Keeping the dough too dry
One common misconception about focaccia is that it is made with a low-hydration dough. If you're making focaccia in a stand mixer, you might be surprised by how wet the dough is, and reach for your flour canister to remedy the situation. To maintain its structure and produce the chewy, delicious texture that the bread is known for, focaccia requires a lot of water; use about 112 cups of water to four cups of flour.
Because of its high hydration, Phil's Home Kitchen suggests working the dough differently than other types of bread dough. You can either place the dough in a stand mixer fitted with a dough hook attachment for 15 minutes or turn and flop the dough on itself for up to ten minutes. The dough may not come together as quickly as other types of dough, but allowing the gluten to develop and proof overnight results in great focaccia and less stress for the baker. In a nutshell, trust the process!