In a big bowl, stir down the poolish, add 75% of the water, and all of the yeast, sugar, salt and the flour. Because the start transformed into a more or less cohesive mixture, it will look funny at the start, but continue, it will mix. Knead until you have a nice dough. You will use nearly all, or all of the water, but again, do not use all if you feel the dough is already quite wet. When you knead, the dough will become tougher anyway, as the flour will absorb the water.