Bulk fermentation and knowing when it's done
This is more or less the big one. Bulk fermentation is the fancy name for the first rise, after you mix the dough and before you shape it. It's the stretch where most of the actual work happens, and it's where most of my early loaves went wrong, so we'll slow down here.
Here's what's happening, in plain terms. Herb — my starter, you'll meet him if you haven't — is full of wild yeast and bacteria. Once he's mixed into your dough, they start eating the sugars in the flour and giving off gas. That gas is what makes your dough rise. Meanwhile the bacteria make the dough more acidic, which is where the sour flavor comes from. I can't take you past that. I know what it does, not exactly why, down at the cell level. For that, there are better people to ask than me.
What you're actually watching for
Forget the clock. I mean that. A recipe might tell you "bulk ferment 4-6 hours," and that number was written in a kitchen that is not your kitchen. We're at about 4,600 feet here, our air is dry, and dough moves faster at elevation than most recipes assume. In summer especially, your dough might be done in three hours when the recipe swears it takes five.
So instead of the clock, you watch the dough. Here's what "done" looks like:
- It's grown. Not doubled necessarily — that's peak territory, which we covered in an earlier lesson, and bulk fermentation is a little different from watching for peak specifically. For bulk, I'm usually after something like 30-50% bigger than when I started, depending on the recipe. It'll say. Read that number, then watch your dough hit it instead of watching the clock hit a time.
- It's smoother and more domed on top, not flat and slack.
- When you poke it gently with a wet finger, it slowly springs back, but not all the way. If it springs back fast and fully, it's not there yet. If it doesn't spring back at all and just sits there with a dent, you've gone too far.
- You can see bubbles under the surface if your bowl is clear enough to check from the side. Little domes here and there.
How to actually do it at home
Mix your dough — flour, water, starter, salt, like we practiced — and get it into a bowl with a lid, or a towel over the top. About that towel: our house air is dry enough that dough will skin over on top if you leave it uncovered, and a crusty skin messes with your shaping later. A damp towel or a lid fixes that completely. Took me embarrassingly long to figure that one out.
Then you do your stretch and folds early on, spaced out over the first hour or two, and after that you mostly leave it alone. Check on it every 30-45 minutes just by looking, not touching too much. Note the time you mixed, and jot down what the dough looks like when you check it. I keep all this in a spiral notebook by my flour bin. Not on my phone — there's a digital version too, somebody set it up for me once, but I still write it down by hand every time. Same as my family tree binder. I like having something I can flip back through. Writing "dough looked slack, kitchen was 68 degrees" in your own handwriting sticks with you differently than a note on a screen.
Signs you've gone too far
Overproofed dough gets puffy and fragile-looking. It might look impressive in the bowl, but when you try to shape it, it deflates and won't hold any tension at all. It'll feel slack, almost slimy, and it tears instead of stretching. If that happens, don't panic and toss it — you can still bake it, it'll just spread out flatter and give you a less open crumb. Take the information and move on. That's the whole sourdough deal. It's forgiving, not fussy. If something goes sideways you don't have a science project ruined, you have information for next time.
Underproofed is the opposite problem — dough that's tight, dense, springs back immediately when you poke it. That'll give you a dense, gummy loaf even if your oven and your scoring are perfect.
My actual opinion here
Watch the dough, not the clock. I say this in basically every lesson because it's the thing that would've saved me a month of frustration. I followed a recipe written by someone at sea level, let my dough go the full time they said, and kept overproofing loaves without understanding why. Once I started watching what the dough actually looked like instead of what the timer said, everything got better. Up here, summer especially, things move fast. Trust your eyes.
Before next time
Mix a dough and just watch it through bulk without doing anything else fancy. Write down what time you mixed, what it looked like every half hour or so, and what time you decided it was ready. Bring that page with you.
- J