My first favorite recipe was a classic baguette. I keep reading to develop flavor you should slow things down. More time and less yeast. For instance the original recipe starts with 60 grams flour/60 grams water with a pinch or 1/16 teaspoon of active dry yeast. I also understand you can refrigerate dough to slow things down even further. My question is how do I slow things down as much as possible while not making a sourdough? I want to increase my flavor without adding any sour to the profile.
At some point you will just develop sourness, whether you want it or not.
I'm sure there are more detailed studies about how much can you slow things down before you sacrifice quality, but making a poolish, then doing a cold bulk fermentation followed by a cold final proof should already do a lot. I'm pretty sure high quality pizza places do that, 48 h fermentations aren't uncommon there.
I just did baguettes using a poolish that had two and a half days to ferment, plus around 20 hours of refrigerated final rise. There's no hint of sourness. OTOH I'm honestly not sure I'd taste much difference if I'd skipped the poolish. In my limited experience beyond, say, 24 hours the benefits of longer fermentation are not that apparent.
I'n my experience you don't get any sour flavours with commercial yeast, even after a very long fermentation. The sourness comes from the lactic and acetic acids produced by the bacteria that live in a sourdough starter.