Sourdough Starter

How to Feed Sourdough Starter: Complete Step-by-Step Guide (2026)

Mariusz Lasak · January 30, 2026 · 13 min read

The first time I fed my starter, I overthought everything. How much to discard? What if I use the wrong ratio? Should the water be exactly room temperature? I spent 20 minutes measuring and second-guessing what should have taken 3 minutes.

After maintaining starters for over 3 years and feeding them hundreds of times, I’ve learned that feeding is straightforward. You discard most of the old starter, add fresh flour and water, mix, and wait. The exact ratio matters less than consistency. The water temperature has a wider tolerance than you think. Your starter is resilient.

This guide covers the complete feeding process – basic technique, different feeding ratios, when to feed, storage schedules, and how to recognize when your starter is ready to use. You’ll learn the method I use and understand why each step matters.

The Basic Feeding Process (Step-by-Step)

The standard method that works every time

This is the basic 1:1:1 feeding ratio (equal parts starter, flour, and water by weight). Once you master this, all other ratios follow the same pattern with different proportions.

What You Need

• Digital kitchen scale (essential for accuracy – measuring by volume doesn’t work)
• Glass jar (16oz/500ml minimum, wide mouth for easy stirring)
• Spoon or fork (any material works – metal is fine)
• Flour (all-purpose, bread flour, or whole wheat)
• Water (filtered, spring, or dechlorinated tap water)
• Rubber band or marker (to track rise)

Understanding Feeding Ratios

What the numbers mean and when to use each ratio

Feeding ratio is written as starter:flour:water by weight. For example, 1:1:1 means equal parts of each. The ratio determines how much food you give the microorganisms, which affects how long the starter stays active.

Why Ratio Matters

The ratio affects fermentation speed:

• More starter (lower ratio like 1:1:1): More microorganisms eating the food = faster fermentation = shorter time to peak. Good for daily feeding and when you want reliable, quick results.
• Less starter (higher ratio like 1:5:5): Fewer microorganisms with more food = slower fermentation = longer time to peak. Good for once-daily feeding or when you need the starter ready at a specific time.

Hydration Level

Most starters are maintained at 100% hydration (equal weight flour and water). This creates a thick but pourable consistency. You can maintain starters at different hydrations (50% for stiff, 150% for liquid), but 100% is standard and easiest for beginners.

When to Feed Your Starter

Reading your starter’s hunger signals

Knowing when to feed matters as much as how to feed. Your starter gives clear visual and olfactory signals about its state.

Signs It’s Time to Feed

Peak has passed:

• Starter has risen to maximum height and started falling
• Surface has collapsed inward or looks deflated
• Still has bubbles but less active than at peak
• Smell becomes more intensely sour or boozy

Clear liquid on top (hooch):

• Gray, brown, or clear liquid layer on surface
• This is alcohol from yeast fermentation
• Means starter is very hungry and needs feeding soon
• Stir it back in or pour it off – both work

Strong acetone smell:

• Very sharp, nail-polish-remover odor
• Indicates overly hungry starter
• Still recoverable – just feed it

Feeding Before Peak

You can feed starter before it peaks, but this creates less predictable results. The microorganisms haven’t fully consumed the food yet, so you’re diluting an incomplete fermentation. This weakens the culture over repeated feedings.

Feeding After Extended Neglect

If your starter sat refrigerated for 2-4 weeks (or longer):

1. Take it out, inspect for mold (fuzzy growth = throw out)
2. Pour off any hooch
3. Feed with 1:1:1 ratio at room temperature
4. Wait 8-12 hours, it may be sluggish
5. Feed again with 1:1:1 ratio
6. By second or third feeding, activity should return

Feeding Schedules by Storage Method

Matching feeding frequency to your baking habits

How often you feed depends on where you store your starter and how frequently you bake.

Room Temperature (Active Maintenance)

Schedule: Feed every 12-24 hours (once or twice daily)

Method:

• Feed when starter passes peak and starts falling
• Typically peaks 4-8 hours after feeding at 70-75°F room temperature
• If you feed in morning, it peaks by afternoon/evening – feed again or refrigerate
• If you feed twice daily: morning feed, evening feed, repeat

Best for: Frequent bakers (3+ times per week), learning starter behavior, building new starter

Pros: Starter stays very active and predictable, always ready for baking

Cons: Requires daily attention, generates more discard

Refrigerated (Low Maintenance)

Schedule: Feed once per week (some starters tolerate 2 weeks)

Method:

• Feed starter at 1:2:2 or 1:5:5 ratio
• Let it ferment at room temp for 1-2 hours (gets activity started)
• Put in refrigerator (35-40°F)
• Cold temperature slows fermentation dramatically
• Once weekly, take out, discard most, feed, let sit 1-2 hours, return to fridge

To use for baking:

1. Remove from fridge 12-24 hours before baking
2. Feed at room temperature
3. Wait for peak activity (8-12 hours)
4. Feed again if needed (2nd feeding often produces more vigorous starter)
5. Use at peak

Best for: Occasional bakers (once per week or less), minimal maintenance

Pros: Very low maintenance, less discard, flexible schedule

Cons: Requires planning ahead for baking, starter less active than room-temp maintained

Dried (Long-Term Backup)

Schedule: No feeding required (dormant state)

Method:

• Spread thin layer of active starter on parchment paper
• Let dry completely at room temperature (24-48 hours)
• Break into flakes and store in airtight container
• Keeps for months or years

To reactivate:

1. Add 1-2 tablespoons dried starter to jar
2. Add 50g water, let hydrate 1 hour
3. Add 50g flour, mix, wait 12-24 hours
4. Feed daily for 3-5 days until consistent activity returns

Best for: Backup in case main starter dies, sharing starter with friends, long travel periods

How to Know Your Starter Is Ready

Visual and physical tests for peak activity

Ready starter has reached peak fermentation – the microorganisms are most active, gas production is maximum, and leavening power is strongest. This is when you use it for baking.

The Four Key Signs

Timing Peak Activity

Peak timing varies based on several factors:

• Temperature: 70°F = 6-8 hours | 75°F = 4-6 hours | 65°F = 10-12 hours
• Feeding ratio: 1:1:1 = 4-6 hours | 1:5:5 = 10-12 hours
• Starter maturity: Young starters (under 2 weeks) slower than mature starters
• Flour type: Whole wheat/rye faster than white flour (more nutrients)

Calculating Exact Feeding Amounts

The math behind different ratios

Understanding the calculation lets you scale feeding up or down based on how much starter you need.

Basic Formula

For any ratio (starter:flour:water), the calculation is:

Working Backwards From Total Needed

If your recipe needs 200g active starter, work backwards:

For 1:1:1 ratio (total = 3 parts):

• 200g ÷ 3 = 66.7g per part
• Use 67g starter + 67g flour + 67g water = 201g total

For 1:2:2 ratio (total = 5 parts):

• 200g ÷ 5 = 40g per part
• Use 40g starter + 80g flour + 80g water = 200g total

Common Feeding Amounts

Common Feeding Mistakes

What to avoid and why

1. Measuring by Volume Instead of Weight

The mistake: Using cups or tablespoons to measure flour and water

Why it’s wrong: Volume measurements are wildly inconsistent. 1 cup of flour can weigh 120g-150g depending on how densely packed. This creates unpredictable hydration and feeding ratios.

Solution: Always use a digital kitchen scale. Weigh everything in grams. Costs $15 and eliminates the biggest source of inconsistency.

2. Using Chlorinated Tap Water

The mistake: Feeding with heavily chlorinated tap water directly from faucet

Why it’s problematic: Chlorine inhibits microbial growth – which includes the beneficial yeast and bacteria in your starter. Heavy chlorination can weaken or slow your culture.

Solution: Use filtered water, spring water, or let tap water sit uncovered for 24 hours (chlorine evaporates). If your tap water is lightly chlorinated, it’s usually fine.

3. Feeding Too Frequently

The mistake: Feeding every 4-6 hours before starter reaches peak

Why it’s wrong: Doesn’t allow complete fermentation cycle. Microorganisms don’t fully consume the food, culture doesn’t strengthen properly, and you create excessive discard.

Solution: Let starter reach peak (doubled, bubbly, passes float test) before feeding. This usually takes 8-12 hours for refrigerated starters returning to room temp, 4-8 hours for actively maintained starters.

4. Not Mixing Thoroughly

The mistake: Leaving dry flour pockets or not incorporating water completely

Why it’s wrong: Dry flour can’t be consumed by microorganisms. Uneven hydration creates inconsistent fermentation. Dry pockets can develop mold.

Solution: Stir vigorously for 30-60 seconds until mixture is completely smooth and uniform. Scrape down jar sides. No dry flour should remain.

5. Sealing Jar Tightly

The mistake: Screwing lid on tight or using airtight container

Why it’s wrong: Fermentation produces CO2 gas. Sealed container can build pressure and potentially explode (rare but possible). Starter also benefits from some air exchange.

Solution: Cover loosely – lid resting on top (not screwed), cloth secured with rubber band, or jar with airlock. Starter needs protection from dust/insects but not an airtight seal.

Troubleshooting Feeding Issues

Solutions to common problems

Problem: Starter Not Rising After Feeding

Possible causes:

• Too cold (below 65°F slows activity dramatically)
• Starter too young (needs more time to establish)
• Chlorinated water killed microorganisms
• Ratio too high (1:10:10 with immature starter can be too much food)

Solutions:

• Move to warmer spot (70-75°F ideal)
• Continue daily feedings for new starters – can take 7-10 days
• Switch to filtered or spring water
• Use lower ratio (1:1:1) to build activity

Problem: Starter Smells Like Acetone/Nail Polish

Cause: Very hungry starter, past peak, producing excess alcohol

Solution: Feed more frequently. If you’re feeding once every 24 hours and getting this smell, feed every 12 hours instead. For refrigerated starter, feed weekly instead of every 2 weeks.

Problem: Hooch Appearing Frequently

Cause: Starter consuming all food and entering starvation phase before next feeding

Solutions:

• Feed more frequently (reduce interval between feedings)
• Use higher feeding ratio (more food = lasts longer)
• Example: If you feed 1:1:1 and get hooch in 16 hours, switch to 1:2:2 or feed every 12 hours instead of every 24

Problem: Starter Takes Forever to Peak (12+ hours)

Possible causes:

• Temperature too cool
• Feeding ratio too high
• Weak or underfed starter

Solutions:

• Increase ambient temperature (place near oven, use proofing box, or warming mat)
• Lower feeding ratio (1:5:5 → 1:2:2 → 1:1:1)
• Feed daily at 1:1:1 for a week to strengthen culture

Problem: Starter Peaks in 2-3 Hours (Too Fast)

Possible causes:

• Temperature too warm (above 80°F)
• Feeding ratio too low
• Very active, healthy starter

Solutions:

• Move to cooler location
• Increase feeding ratio (1:1:1 → 1:5:5 or higher)
• If starter is just very strong, this isn’t a problem – use it when ready or increase ratio for longer window

Conclusion: Feeding Becomes Second Nature

When I started maintaining a starter, feeding felt like a delicate science experiment. Measure precisely, check temperature, watch timing obsessively. Within a few weeks, it became routine. Now I feed my starter while coffee brews – weigh jar, dump excess, add flour and water, stir, mark level, done.

The process doesn’t change. Discard, feed, wait for peak, use or refrigerate. The variables change (ratio, temperature, timing) based on your schedule, but the fundamentals stay the same.

Once you’ve fed your starter 10-15 times, you’ll develop a feel for it. You’ll recognize peak just by looking. You’ll know if your kitchen is warm or cool and adjust timing accordingly. Feeding transforms from a careful procedure into an automatic habit.

The reward is consistent access to active starter that produces better bread than commercial yeast can deliver. That’s worth 3 minutes of weekly maintenance.

Frequently Asked Questions