For the life of me, I can't figure out why my dough is losing shape when I remove it from the banneton.

When was the last time you followed the recipe and it came out okay,  and how long has it been showing a problem?  If it came out okay before, than the problem is likely either the flour or the temperature, since it is likely everything else  ( meaning the process, the water, and the salt ) has stayed the same.

If you last had it come out well much earlier in the year, it could be that the final proof is at a warmer temp in your house, which would cause it to overproof if you followed the same timing.  As you increase the temperature, the yeast activity speeds up as well.

If temperatures are the same for both, it is possible there is a difference between the flour you were using and the flour you are using now.  Even if it is from the same manufacturer, the properties may be different ,  since they can vary from batch to batch, and especially lately, there have been some stresses on supply chains. 

I

Hi, Cantbake!

Helping you troubleshoot this with any degree of accuracy is going to be difficult with the very limited information you’ve provided.  Some more details would be extremely helpful.

Having looked at the recipe you linked to, a few things that I notice off the top of my head is that the recipe gives you the option of either weighing ingredients (very accurate) or measuring by volume (which can be wildly inaccurate).  Are you weighing or scooping your ingredients?  Another thing that I notice is that the recipe tells you times for how long to let it rise and how long to let it rest (also known as bulk ferment), but the recipe makes no mention of temperatures.  The temperature of the dough, as well as the ambient temperature of your kitchen, is directly linked with the amount of time the bulk ferment process will take (as is the strength and maturity of your starter).  If your kitchen is hotter than usual, then bulk ferment times will need to be adjusted to prevent overproofing, which is what (according to what you say about the dough splaying out when dumped from the Banneton) sounds like is happening.

Sourdough baking is a bit more complicated than baking with commercial yeast.  Because of the nature of wild yeasts, the process becomes more involved than simply “do this, wait exactly one hour, then do that…”  Any slight change in one aspect will require a slight adjustment to another.  Following the recipe to a T is fine, but you must be prepared to be flexible with following the procedures.  In other words, don’t get too caught up on how long a recipe tells you something will take, focusing instead on learning to read what the dough is telling you.

By all means, keep at it!  100% of your successes and 93.4% of your failures will be perfectly edible (and also quite tasty!)  Practice, patience, and perseverance, tempered with curiosity and observation, will ultimately make you a better baker.  Then you’ll have to change your screen name ?

I just had a batch like that. I over proofed it before going into the fridge. 5 degrees difference in temperature got me. I have had better results going straight from fridge to oven. With just enough time to flip onto parchment and score. 

What you’re describing sounds like a dough that has overproofed.  When it overproofs there is excessive proteolytic activity which breaks down the gluten in the dough.  This causes it to lose structure as you have described by the dough splaying outwards out of the banneton.

With the warmer temperatures of the summer in the northern hemisphere many bakers are dealing with more rapidly fermenting dough.  To slow things down you could consider mixing with cooler water than usual, that is probably the easiest change to make.  Reducing the amount of levain will also help.

I would certainly also bake the dough directly out of the fridge rather than letting it bench rest at room temperature for 1.5 hours prior to baking.

Benny