If your sourdough starter seems stuck barely rising, not bubbling, or simply sitting there, don’t panic. This is one of the most common beginner frustrations, but it’s also one of the easiest to fix with the right tweaks.
Let’s dive into what affects starter growth, how feeding ratios play a part, and how to troubleshoot step-by-step to get your starter thriving again.
Temperature: The Growth Engine
Temperature is one of the biggest factors in starter growth. If your starter isn’t rising, chances are it’s either too cold or too warm.
✅ Ideal Range: 25-28°C
This is the sweet spot where yeast and bacteria thrive and work together to create fermentation bubbles, aroma, and structure.
Too Cold = Slow Fermentation
If your kitchen is below 22°C, your starter might be alive and healthy, it’s just working slower than you’d expect. It may take more time to rise or show signs of life.
Too Warm = Starter Stress
Ironically, going too warm can also be a problem. If your starter sits above 28°C for long periods, it may ferment too fast, break down too quickly, or become overly acidic, all of which can lead to a runny or sluggish starter.
Beginner Tip: Warm But Safe
Try placing your starter:
- In your oven with the light on (but no heat)
- Near a warm appliance like a fridge or microwave
- Wrapped in a tea towel in a warm corner of your kitchen
Flour Quality & Type
What you feed your starter matters just as much as when.
Use High-Protein Flour
Our included flour is ideal. It contains 12.5% protein, which builds strong gluten and feeds the microbes well. If you’re using supermarket flour, check the protein percentage (aim for 12%+).
Boost with Rye or Wholemeal
If your starter feels weak or slow, try adding 1-2 tablespoons of wholemeal or rye flour into your regular white flour feed. These flours are rich in wild yeast and natural nutrients that can give your starter a kickstart.
Beginner Tip: Don’t switch flours constantly. Consistency helps your starter stabilise faster.
Understanding Feeding Ratios (With Gram Examples)
Feeding ratios refer to the amount of starter : flour : water you use by weight. Adjusting this affects how fast your starter grows and how thick or runny it becomes.
🔹 1:1:1 Balanced Standard
50g starter + 50g flour + 50g water
Perfect for most situations. Rises steadily and gives consistent results.
🔹 1:2:2 Slower Ferment, More Strength
25g starter + 50g flour + 50g water
Used to refresh a starter or slow fermentation in warm climates.
🔹 1:2:1 Thicker Mix
25g starter + 50g flour + 25g water
Leads to a stiffer, doughier consistency. Holds gas better and rises higher, especially in warm kitchens.
What It Means:
- Thicker starter = more structure, better at holding bubbles
- Runny starter = too warm, fermentation is racing ahead and breaking things down
- No change = too cool, not enough activity to build strength
Beginner Tip: Use a digital scale for accurate feeds. It makes a big difference in consistency.
Feed Daily, Even If There’s No Growth
It’s easy to get discouraged when your starter doesn’t seem to be doing anything but fermentation starts before it becomes visible. Stick with it!
Discard and Feed Every 24 Hours
Discard most of your starter each day and feed with fresh flour and water. This resets the balance and keeps the microbes happy.
Use Filtered Water
Some tap water contains chlorine, which can harm your starter. If you’re unsure, use filtered or boiled (then cooled) water.
Trust the Process
Even if you’re not seeing bubbles or rise, the culture is building strength. With the right feeding routine, it will start to grow.
Beginner Tip: Mark your jar with a rubber band or whiteboard marker so you can track how far your starter has risen.
How to Refresh Your Starter
If your starter still isn’t improving after a few days of feeding, it may just need a good refresh.
✅ Here’s What to Do:
- Discard all but 25g of your starter.
- Feed with 50g flour and 50g water (1:2:2).
- Place in a warm spot (around 25-28°C).
- Feed every 24 hours for the next 3-5 days.
- Watch for signs of activity: rising, bubbles inside, and a tangy smell.
With a little patience and consistency, your starter will begin to double in size and show all the right signs of fermentation.
Final Thoughts
Bringing a slow starter back to life doesn’t take anything fancy; just the right temperature, the right flour, and a little routine. Stick to a 24-hour feeding schedule, use high-quality ingredients, and experiment with feeding ratios to see what works best in your environment.
And most of all, don’t give up too soon. Even if your starter doesn’t look alive on the surface, there’s plenty going on beneath it. We’re here to help you every step of the way.