Feeding Your Sourdough Starter: When, How Much, and Which Flour

Your sourdough starter is alive. It's a thriving colony of wild yeast and lactic acid bacteria, and like any living thing, it needs food. Feeding your starter correctly is the single most important skill in sourdough baking. Get this right and everything else becomes easier. Get it wrong, and you'll be chasing problems from your first mix to your last bake.

The good news? Feeding a starter is simple once you understand the basics. Let's walk through exactly when to feed, how much to use, and which flours work best.

The Golden Ratio: 1:1:1

The standard feeding ratio is 1 part starter : 1 part flour : 1 part water by weight. If you keep 50g of starter, you add 50g of flour and 50g of water. That's it. This ratio works beautifully for daily maintenance and gives your starter enough food to stay active without producing too much discard.

For baking days when you need a stronger rise, bump up to a 1:2:2 or even 1:5:5 ratio. Higher ratios give the yeast more food, which means a longer, more vigorous rise and a milder flavor. Lower ratios (like 1:1:1) ferment faster and produce more acidity, which is great for that classic tangy taste.

When to Feed: Reading the Signs

Timing your feeds isn't about the clock. It's about watching your starter. Here are the key signals:

• Peak: Your starter has roughly doubled in volume and the surface is domed. This is when it's most active and ready to leaven bread.
• Just past peak: The surface starts to flatten or you see the first signs of collapse. Feed now if you're maintaining it.
• Hooch: A layer of dark liquid on top. This is alcohol produced by hungry yeast. Your starter is overdue for a feed but not ruined.

At room temperature (around 21-24C), most starters hit their peak 4-8 hours after feeding with a 1:1:1 ratio. In a warmer kitchen, it'll be faster. In a cooler one, slower. Once you get a feel for your starter's rhythm, timing becomes second nature.

Room Temperature vs. Fridge Storage

If you bake several times a week, keep your starter on the counter and feed it once or twice daily. This keeps the culture at full strength and ready to go whenever you want to mix a dough.

If you bake less frequently, the fridge is your best friend. After a fresh feed, let the starter rise for about an hour at room temp, then pop it in the fridge. The cold slows fermentation dramatically, meaning you only need to feed it once a week. When you're ready to bake, take it out, give it one or two room-temperature feeds, and it'll bounce right back.

Which Flour Should You Use?

You can maintain a sourdough starter on almost any wheat flour, but different flours produce different results:

• White bread flour (strong flour): The most common choice. Produces a consistent, predictable starter with a mild flavor. High protein content gives good structure.
• Whole wheat flour: Ferments faster because the bran and germ provide extra nutrients for the microbes. Produces a slightly more sour starter. Great for boosting a sluggish culture.
• Rye flour: The powerhouse. Rye ferments the fastest of all common flours and is packed with nutrients that your starter loves. Even a small percentage of rye in your feed can supercharge activity. If your starter is sluggish, switch to rye for a couple of feeds.
• All-purpose flour: Works fine but has less protein than bread flour, so your starter may be a bit less vigorous. Perfectly acceptable for maintenance.

Many experienced bakers use a blend. A popular maintenance mix is 80% white bread flour and 20% whole wheat or rye. This gives you the consistency of white flour with a nutritional boost from the whole grain. Experiment and find what works for your baking schedule and flavor preference.

Common Feeding Mistakes

• Using hot water: Water above 40C can damage or kill the yeast. Use lukewarm water (around 25-30C) or room temperature.
• Skipping the discard: If you never discard, your starter grows exponentially and the ratio of old, spent culture to fresh food gets out of balance. Always discard (or use it in discard recipes like focaccia) before feeding.
• Inconsistent feeding schedule: Your starter adapts to a rhythm. Wild swings between 8-hour and 48-hour gaps stress the culture. Find a routine and stick to it.
• Sealed containers: Your starter produces CO2. A tightly sealed jar can build pressure. Always use a loose lid or a jar with a vent.

A Simple Daily Routine

That's really all there is to it. Feeding your starter isn't complicated, but doing it consistently makes an enormous difference in your baking results. A well-fed starter rises predictably, produces better flavor, and gives you the oven spring that makes sourdough so satisfying.

If you're just getting started on your sourdough journey, check out our complete guide to creating a starter from scratch. Already have a healthy starter? Put it to work with our first sourdough loaf recipe.