Sourdough Starter Feeding Ratios Explained

If you’ve spent any time reading about sourdough starters, you’ve run into notation like 1:1:1 or 1:2:5 and maybe felt a flicker of confusion. What do those numbers mean? Which ratio should you use? Does it actually matter?

It does matter, and once you understand what the numbers represent, feeding your starter becomes much more intuitive. You stop following instructions blindly and start adjusting your routine to fit your actual baking schedule.

What the Numbers Mean

A starter feeding ratio is written as three numbers: starter : flour : water. Each number represents a relative weight, not a volume.

So a 1:1:1 ratio means equal weights of starter, flour, and water. If you keep 50g of starter, you’d add 50g of flour and 50g of water. A 1:2:5 ratio means one part starter, two parts flour, five parts water. With 20g of starter, you’d add 40g of flour and 100g of water.

The ratios are always by weight. Measuring by volume introduces too much inconsistency, especially with flour, which packs differently depending on how you scoop it. A kitchen scale is worth every penny here.

What Feeding Ratio Actually Controls

The ratio you feed your starter determines two things: how long it takes to reach peak activity, and how long it stays at peak before starting to decline.

A smaller ratio (like 1:1:1) gives the existing culture a relatively small amount of fresh food. The yeast and bacteria consume it quickly and the starter peaks fast, often within 4 to 8 hours at room temperature. This is useful when you want to bake the same day or when you’re building an active starter back up after refrigeration.

A larger ratio (like 1:5:5 or 1:2:5) dilutes the existing culture more heavily and gives it a much larger supply of fresh flour. It takes longer to peak, often 10 to 14 hours or more, but it also stays at peak longer before falling. This is useful for overnight schedules, for bakers who don’t want to watch the clock too closely, or for situations where you need your starter to be ready at a specific time in the morning.

Think of it this way: a small ratio is like giving your starter a small snack it finishes quickly. A large ratio is a full meal it works through more slowly.

Common Ratios and When to Use Them

1:1:1 (same-day baking) Equal parts starter, flour, and water. This is the most common starting point for beginners because it’s easy to remember. It produces a starter that peaks relatively quickly, usually within 4 to 8 hours depending on temperature and starter health. Good for baking the same day, building an active culture after cold storage, or daily maintenance if you bake frequently.

1:2:2 (flexible timing) One part starter, two parts flour, two parts water. Peaks a bit slower than 1:1:1, typically 6 to 10 hours. A good middle-ground ratio for bakers who want a little more flexibility in their timing without committing to a very long window.

1:3:3 or 1:5:5 (extended timing) These larger ratios push peak timing to 10 to 14 hours or beyond at room temperature. Very useful for overnight schedules where you feed before bed and want the starter ready in the morning. Also helpful in warm kitchens where a 1:1:1 starter might peak and fall before you’re ready to use it.

1:2:5 (stiff-style variation) Sometimes seen in recipes that use a stiffer levain. The lower water ratio produces a firmer starter with a slightly different flavor profile, often described as milder and less acetic. Less common for everyday maintenance but worth knowing about.

The right ratio depends on your kitchen temperature and your schedule more than anything else. A ratio that works perfectly in a cool winter kitchen may overshoot in a warm summer one. The CrumbDesk Starter Feeding Calculator lets you plug in your conditions and get a tailored recommendation without the guesswork.

How Hydration Factors In

The third number in the ratio — the water — also controls your starter’s hydration level. Equal flour and water weights (as in 1:1:1 or 1:3:3) produces a 100% hydration starter. More water than flour pushes it above 100%. Less water pulls it below.

Most home bakers maintain a 100% hydration starter because it’s easy to calculate and behaves predictably. A more liquid starter (above 100%) tends to be more active and peaks faster. A stiffer starter (below 100%) ferments more slowly and often develops more mild, complex flavor over time.

Unless you have a specific reason to change your starter’s hydration, keeping the flour and water equal in your feeding ratio keeps things simple. If you want to understand how hydration affects the rest of your bake, the CrumbDesk Hydration Calculator is a good place to explore the relationship between water ratios and dough behavior.

How Much Starter to Keep

Feeding ratio and the amount of starter you keep are separate decisions, but they interact. The more starter you keep, the more flour and water you need to feed it. Many home bakers find that keeping a small amount — 20 to 50 grams — makes feeding more economical, especially if you’re maintaining your starter daily.

The discard portion (the starter you remove before feeding) isn’t wasted. It can go into pancakes, crackers, waffles, pizza dough, and dozens of other recipes. Treating discard as an ingredient rather than waste makes the whole routine feel less fussy.

If you’re building up a large batch for a specific bake, you can scale your feeding up deliberately rather than maintaining a large jar all the time. Feed a small amount of starter with a larger ratio to grow it to the quantity you need, then use it at peak.

Feeding Ratio and Your Baking Schedule

The most practical reason to understand feeding ratios is schedule control. Once you know that a 1:5:5 feed will peak in roughly 12 hours in your kitchen, you can feed at 9pm and have a ready starter at 9am. Feed at 7am with a 1:1:1 ratio and you’re mixing dough by early afternoon.

This matters because your starter’s peak readiness directly affects your bulk fermentation timeline. A starter used at or near peak will ferment your dough predictably. Starter used too early (before peak) or too late (after it’s started falling) introduces unpredictability into the bulk that can be hard to diagnose.

Getting your feeding ratio and timing dialed in is one of the highest-leverage things you can do to make your bakes more consistent. Everything downstream, including bulk fermentation and final proof, goes more smoothly when your starter is doing its job reliably.

A Simple Way to Find Your Ratio

If you’re not sure what ratio works for your kitchen, start with 1:2:2 and observe. Note what time you feed, check every couple of hours, and mark when the starter peaks (highest rise before it starts to fall back) and when you actually need it ready.

If it peaks too fast, try 1:3:3 or 1:5:5. If it’s taking longer than you want, try 1:1:1 or 1:2:2. Two or three test runs in your actual kitchen at your actual ambient temperature will tell you more than any general guideline.

Temperature is the biggest variable, so if your kitchen changes significantly between seasons, expect to adjust your ratio accordingly. What works in October may need tweaking in July.

Feeding ratios are one of those things that seem fiddly until they’re not. Once you find the ratio that fits your schedule and kitchen, you’ll feed your starter on autopilot and barely think about it. The goal is a reliable peak that shows up when you need it, every time.

To find the right ratio and quantities for your specific setup, plug your numbers into the CrumbDesk Starter Feeding Calculator and get a clear recommendation based on your conditions.

FAQ

What is the best sourdough starter feeding ratio? There’s no single best ratio. For most home bakers baking the same day, 1:1:1 or 1:2:2 works well. For overnight schedules or warmer kitchens, a larger ratio like 1:3:3 or 1:5:5 gives you more flexibility. The right ratio is the one that puts your starter at peak when your schedule needs it.

How often should I feed my sourdough starter? If you bake several times a week, feeding daily at room temperature makes sense. If you bake once a week or less, storing your starter in the fridge and feeding it once a week (or the night before a bake) is more practical. Refrigerated starters can go 1 to 2 weeks between feedings without significant harm.

Does feeding ratio affect starter flavor? Indirectly, yes. Larger ratios dilute the acidity of the existing culture, which can produce a milder, less sour starter. Smaller ratios allow more acidity to accumulate, which some bakers prefer for more tangy bread. The effect is subtle for most home bakers but becomes more noticeable in the final loaf over time.

What happens if I feed my starter with the wrong ratio? Nothing catastrophic. If you use too small a ratio the starter will peak and fall faster than expected. Too large a ratio and it will take longer to peak. You’ll still get usable starter either way — you’ll just need to adjust your timing for that bake. Consistent ratios over time make your process predictable.

Can I change my starter’s hydration by adjusting the feeding ratio? Yes. If you feed with equal weights of flour and water, your starter stays at 100% hydration. More water than flour pushes hydration higher and produces a more liquid, active starter. Less water produces a stiffer starter that ferments more slowly. Most bakers maintain 100% hydration for simplicity.

How do I know when my starter has peaked? Peak is when the starter has risen to its maximum height before beginning to fall. You’ll see a domed top, lots of bubbles throughout, and a slightly open, airy texture. Many bakers use a rubber band or piece of tape on the outside of their jar to track rise. The starter is at or near peak when it passes the float test: a small spoonful dropped in water floats rather than sinking.

Does the type of flour I use for feeding matter? It does. All-purpose and bread flour are the most common choices for feeding because they’re consistent and widely available. Whole wheat flour adds more nutrients and microbial diversity, which some bakers find produces a more vigorous starter. Rye flour is especially active and can speed up fermentation noticeably. Many bakers add a small percentage of whole wheat or rye to each feeding for this reason.