Sourdough Starter Not Doubling: Temperature Flaw or Feeding Error?

Hey @brooklynrivera, I've had my fair share of sourdough starter struggles too. Even with all your careful tracking, 24-hour intervals might be too long if your starter isn’t active enough at cooler ambient temperatures. Though you warm your water, your fermentation environment might still be sluggish. I’d suggest trying a slightly shorter feeding cycle—maybe 12 to 16 hours when activity seems to drop off—to see if that gives your culture a steadier boost.

Regarding pH and protein, a water pH of 7.2 usually isn’t a deal breaker, but a hint more acidity can encourage yeast growth. If possible, consider experimenting with a small batch using a blend of your organic rye with a touch of a higher protein bread flour. Sometimes even a minor tweak can make all the difference. Keep at it—sourdough is as much an art as it is a science!

@brooklynrivera, I’ve been through this frustrating phase, and honestly, the 24-hour feeding schedule can be killer if your starter peaks at 6 hours and then just crashes. You’re basically starving it for the remaining 18 hours, which stresses the yeast and bacteria. Try shortening your feeding intervals to 12 hours at first and see if the starter maintains its rise instead of collapsing.

Also, I’d second playing with flour blends. Rye gives great flavor and activity early on, but adding some high-protein bread flour can provide more consistent gluten and nutrients, helping the starter stabilize and rise better. As for your water pH, 7.2 is pretty neutral and shouldn’t be the issue; if anything, you could try a tiny splash of filtered lemon juice to nudge acidity, but don’t overdo it.

Keep tracking your logs, but be ready to adapt—starters are living things, not machines. The moment I accepted that and adjusted feedings dynamically, my starter went from sluggish to reliably doubling every 6–8 hours. Don’t let rigid timing hold you back!

Hey @brooklynrivera, I've had my fair share of sourdough mishaps too. When your starter hits its peak at 6 hours and then drops off, it feels like you’re feeding it on a strict intermittent fasting schedule—it just doesn't get enough fuel over the long haul. Maybe try shortening the feeding interval to around 12–16 hours to keep the dough's microbial population consistently fed and active. I also wonder if the temperature fluctuations between your water and ambient settings are slowing things down; a little extra warmth might stabilize the fermentation process. Mixing a bit of high-protein bread flour with your rye could offer a better nutrient profile and help boost the rise. Sometimes these adjustments, no matter how small, make a huge difference. Keep tweaking and tracking your logs—it’s a messy art form, but the result is totally worth it. Good luck, and happy baking!

Ugh, I feel your pain—sourdough starters can be such divas. You’ve done the hard work of tracking everything, but 24-hour feedings are *way* too long if your starter peaks at 6 hours. That’s like expecting a toddler to thrive on one meal a day. Try feeding every 12 hours, or even 8 if it’s still sluggish. And honestly, 72°F ambient is on the cooler side for sourdough; yeast gets lazy below 75°F. If you can, find a warmer spot—top of the fridge or near a lamp.

As for flour, rye is great for kickstarting activity, but it’s not the most stable long-term. I’d switch to a 50/50 mix of rye and high-protein bread flour (like King Arthur) to give the yeast more to chew on. Your water pH is fine—don’t overcomplicate it. The real issue is likely temperature and feeding frequency. And if you’re still not seeing growth, try a tiny pinch of sugar in one feeding to see if it perks up.

Keep at it, but don’t let it stress you out. Even the best bakers have starter drama—it’s part of the process. (And if all else fails, just name your starter and yell at it. Sometimes that helps.)

Oh my god, @azariahkim, you nailed it—sourdough starters are absolute drama queens! I’ve had my own battles with them, and the 24-hour feeding schedule is just setting you up for failure if your starter’s already peaking at 6 hours. That’s like expecting a marathon runner to survive on a single granola bar. Every 12 hours is a solid starting point, but honestly, if it’s still acting sluggish, don’t be afraid to go even shorter. Yeast doesn’t care about your sleep schedule.

And yes, temperature is everything! 72°F is basically a yeast retirement home. I’ve had to resort to sticking my jar on top of my router (don’t judge) to keep it warm enough. A lamp or the fridge trick works too—just don’t let it get too hot or you’ll end up with a starter that’s more vinegar than bread.

As for flour, I’m all for the 50/50 rye and bread flour mix. Rye’s great for that initial boost, but bread flour gives it the structure to hold a rise. And if you’re really desperate, a tiny pinch of sugar can be a lifesaver—just don’t make it a habit or you’ll end up with a sugar-dependent starter (yes, that’s a thing).

Hang in there, @brooklynrivera! Starters are like moody pets—sometimes they just need a little extra love (and warmth). And if all else fails, naming and yelling at it is a time-honored tradition. Mine’s called Kevin, and he knows when he’s being lazy.

@abigailparker93 Thank you for the thorough reinforcement! I appreciate the validation on tightening the feeding schedule—I’d suspected 24 hours was too lax given my starter’s rapid initial activity. I’ll shift to 12-hour feeds immediately and monitor closely. Your router hack is ingenious (no judgment here—I’ve used seedling mats!). I’ll aim for 80–82°F and watch for vinegar signs. The sugar tip is noted as an emergency measure only. Naming it feels necessary now—"Petri" (as in dish) seems fitting for this finicky culture. Your insights resolved my core doubts. Thanks!

Glad you’re moving to 12-hour feeds—honestly, that’s where the magic happens for starters showing early peaks. Keeping the temp around 80–82°F is solid; anything cooler just drags fermentation into molasses speed. I love that you’re watching for vinegar signs—that sour punch is a clear red flag that your starter’s starving or stressed. If that happens, sometimes I’ve found doubling the feeding volume (like a 1:2:2 ratio) helps reset the balance faster than just sticking to 1:1:1.

Also, naming your starter “Petri” is straight-up brilliant. It’s funny, but giving these cultures personality actually helped me be more patient and attentive instead of rushing the process. Just don’t get too attached if it throws a tantrum—it’s a living thing, sure, but it’s not a pet.

One thing I’d warn against: rely on the sugar trick sparingly. Overfeeding sugar can mask underlying issues and create a false sense of progress. Better to tweak temp and feeding intervals first. Keep us posted!

Completely agree on the 12-hour feeds and temp boost—those are non-negotiables. But Caleb, I think you're underselling how stubborn starters can be about temperature. Router hacks? Seedling mats? That’s overkill. I just use my oven with the light on—consistent and zero effort.

Sugar is a hard no for me. If my starter needs sugar to perform, it’s getting tossed. Why coddle a culture that can’t thrive on flour and water alone? That’s just delaying the inevitable.

Naming it "Petri"? Cute, but I’ve never named mine. If it acts up, I’m ruthless—discard and restart. Sentimentality doesn’t bake bread. Keep it simple: tight schedule, steady warmth, and no shortcuts. If it fails after that, your flour’s the issue. Switch brands.