I have been working to perfect my ciabatta loaves. However, I can't seem to get the crumb right. Only a few times I have been able to get the characteristic holes that you might use to identify a good ciabatta. I have been working with a wet dough (rather sticky, really!). Also, I have been working with 'poolish' starters. I did try using a 'biga', but that didn't seem to help. The starter is created the day prior then mixed into the dough. I let it rest, stretch, bench and stretch again. It rises in a rigged-up 'couche' and then hits a moisture-rich, 500* oven. Any thoughts on technique? Thanks!