Flying crust-- potato sourdough
Hello! I'm a new member, but over the past few weeks I have been browsing all the useful advice on TFL. Now I finally signed up, I hope you all can help me with this problem.
I just bought Dan Lepard's The handmade loaf and was trying out the crusty potato bread today using my 3 week old white starter that I kept at 1:1:1 feeding (weekly usually) in the fridge. I took my starter out for feeding yesterday evening, and seeing that it was still quite lively (I baked earlier this week), I decided to bake today after only 1 feeding yesterday. Following Lepard's starter recipe, I did 80% water and 100% white flour instead of my usual ratio. The starter doubled in volume overnight and I followed Lepard's recipe nearly exactly (I shortened the bulk ferment by 1 hour or so) using the french fold technique initially as well as stretch & fold. The final rise was 4 hours. When I tried to tip the doughs out onto the baking tray, they stuck quite a bit.
After baking, they came out with big air holes throughout (like a ciabatta) except a few massive ones near the top. It taste okay though (not too sour)
So my questions are...
1) could this be due to the way i stretch and fold (trapping air bubbles)? I only recently started using this technique and previously never had flying crust problem (well, I've only been baking sourdough for a month)
2) The recipe was of 60% hydration (as well as having grated potato), is that why I have so many holes throughout? Surely this not supposed to happen. Have I overproved it (another reason for the flying crust perhaps)?
3) So far I've only been making round-shaped bread (thats the shape of my proving basket!), should I try other shapes?
ps. I would like to post a photo but havent quite figure out how yet!