If you’ve ever gone looking for a sourdough starter kit online, you’ve probably seen little packets of dried “sourdough culture” for $10–$15 (sometimes even more!). Here’s the thing—you don’t need them. All you actually need is flour and water. The wild yeast and good bacteria that make sourdough work are already there, just waiting to come alive in your kitchen.
Now, I will say this: a good starter jar really helps. It makes the whole process cleaner, easier, and way less messy. I’ve tried a few, and this is the one I use and absolutely love. It’s sturdy, easy to clean, and the perfect size for keeping your starter happy.
💡 Pro Tip: Skip the culture kits, invest in the jar! You’ll use it over and over again, and it makes the process so much smoother.
And here’s something most people don’t realize—even if you do buy one of those “official” culture packs online, you’re still going to go through the exact same 5–7 day process to wake it up and build strength. So why waste the money? With a jar, some flour, and a little patience, you’ll have a bubbling, healthy sourdough starter that’s completely your own.
Let’s walk through the simple step-by-step process.
What You’ll Need
- Organic, unbleached white flour (whole wheat flour works too if you want to kickstart fermentation, but white flour is great for maintenance)
- Water (filtered or dechlorinated if possible)
- A clean glass jar or container with cloth cover
- A spoon or spatula
Step-by-Step Instructions
Day 1 – Mix the Base
- In a clean jar, combine 100 g flour with 100 g water (about ½ cup of each).
- Stir well until no dry flour remains. The mixture should look like thick pancake batter.
- Cover loosely (a lid set on top or a cloth with a rubber band) and leave it at room temperature (ideally 70–75°F).
Day 2 – Check & Feed
- You might see a few bubbles already, or it might look the same—that’s normal.
- Discard about half of the mixture (so you’re left with ~100 g).
- Add 100 g fresh flour and 100 g water. Stir thoroughly and cover again.
Day 3 – Signs of Life
- By now, you should notice some bubbling, a slightly tangy aroma, and maybe some rise in the jar.
- Discard half again, and feed with the same ratio: 100 g flour + 100 g water.
Day 4 – Growth Spurt
- The starter should be noticeably active now—bubbles throughout, a mild sour smell, and maybe doubling in size between feedings.
- Continue the same feeding routine: discard half, then refresh with flour and water.
Day 5–7 – Strengthening the Starter
- Keep feeding daily. By Day 5 or 6, your starter should reliably double in size within 4–8 hours of feeding.
- To test if it’s ready to bake, do the “float test”: drop a spoonful of starter into a glass of water. If it floats, it’s airy and ready for bread.
Tips for Success
- Temperature matters: Starters like warmth. If your kitchen is chilly, fermentation may take longer.
- Be consistent: Feeding around the same time each day helps build a strong culture.
- Switch flours if needed: Whole wheat or rye can boost activity if your starter seems sluggish.
- Don’t worry about smells: Early on, starters can smell odd (fruity, cheesy, or even like nail polish). This is normal. With regular feedings, the good microbes will take over.
Maintaining Your Starter
Once your starter is strong and bubbly, you can keep it alive indefinitely:
- If you bake often: feed daily at room temperature.
- If you bake less frequently: store it in the fridge and feed once a week.
Final Thoughts
Making your own sourdough starter is one of the most satisfying steps in baking. Not only do you save money by skipping the overpriced kits, but you also get the joy of cultivating your very own wild yeast culture from scratch. With just flour, water, and a little patience, you’ll have a living starter ready to bake those gorgeous, crusty sourdough loaves.
👉 Ready to bake? Get everything you need to start your sourdough journey right here.
👉 Want the exact recipe I use? Grab my favorite, tested Classic Sourdough Bread Recipe here.