Keeping a Sourdough Starter Alive

If you’ve started sourdough, you’ve probably asked yourself at least once:

“How do I not kill this thing?”

Good news — sourdough starters are far more resilient than people think.

I keep mine at 100% hydration, store it in the fridge between uses, and bake with it 1–2 times per week. It’s simple, sustainable, and low maintenance.

Let’s walk through exactly how to keep your starter alive — long term.

What Does 100% Hydration Mean?

100% hydration simply means: Equal weight of flour and water. Not equal volume — equal weight.

For example:

50 g water + 50 g flour
100 g water + 100 g flour
4 oz water + 4 oz flour

At 100% hydration, your starter will be thick but stirrable — like pancake batter.

How I Maintain My Starter (Fridge Method)

After feeding and letting it become active, I store my starter in the refrigerator.

Since I bake 1–2 times per week, here’s what that looks like:

Typical Feeding

50 g starter (1.8 oz | about ¼ cup loosely measured)
100 g water (3.5 oz | about ½ cup)
100 g flour (3.5 oz | about ¾ cup loosely measured)

This is a 1:2:2 ratio.

Let it rise at room temp until active (usually around 8 hours), then store in the fridge.

How Long Can Starter Stay in the Fridge?

If you bake weekly:

Feed once per week.

If you bake every other week:

Feed every 10–14 days.

If life gets busy?

Healthy starters can survive:

3–4 weeks with no feeding
Some people report 2–3 months in the fridge

I’ve heard from friends who’ve left theirs in the fridge for 2–3 months, then fed it a couple of times at room temperature and brought it right back to life. If it develops hooch (liquid on top), that’s okay. Stir it in or pour it off and feed.

If it smells like acetone or nail polish remover — it’s just hungry.

If you see pink, orange, or fuzzy mold — discard and start fresh.

Understanding Feeding Ratios (The Math Made Simple)

Feeding ratios are written like this:

Starter : Flour : Water

1:1:1

50 g starter
50 g flour
50 g water

Faster fermentation. Smaller rise window. Rises faster and falls faster.

1:2:2 (My Usual)

50 g starter
100 g flour
100 g water

Balanced and predictable.

1:5:5

20 g starter
100 g flour
100 g water

Slower fermentation. Great for warm kitchens or a wider time range for use.

1:10:10

10 g starter
100 g flour
100 g water

Very slow, strong feeding. Good for strengthening a weak starter.

Higher ratios = slower fermentation = longer peak window.

What About Discard?

When feeding, you remove some starter to keep it from growing endlessly.

Instead of throwing it away, I collect mine in a jar in the fridge.

Yes — from the same jar.
Yes — for months.

Because discard is unfed starter, it becomes more acidic over time, but that acidity actually works well in many recipes.

How Long Is Discard Good For?

In the fridge:

Easily 1–2 months
Often longer if it smells clean and tangy
No mold, no off colors

Stir occasionally if liquid forms.

What to Watch For (And What’s Totally Normal)

Sourdough starters look… alive. Because they are.

Here’s how to know what’s fine — and what’s not.

Hooch (Liquid on Top)

You may see a gray, brown, or clear liquid forming on top of your starter.

That’s called hooch. It simply means your starter is hungry. You can:

Stir it back in for a more tangy flavor
Or pour it off before feeding

Either way is fine. Hooch is not mold. It’s just fermentation byproduct.

Strong Smell (Acetone or Nail Polish Remover)

If your starter smells sharp, like acetone, that just means it needs food.

Feed it a couple of times at room temperature using a higher ratio (like 1:5:5 or 1:10:10), and it should bounce back.

Thin or Sluggish Texture

If it looks watery or isn’t rising well it may just be cold from the fridge or it may need 1–2 room temperature feedings to strengthen. Most starters recover quickly.

Mold (This Is When You Toss It)

Mold is the one thing that means it’s time to discard and start fresh.

Look for:

Pink streaks
Orange spots
Fuzzy green, black, or white growth
Anything that looks hairy or powdery

If you see mold, do not try to scrape it off.

Discard the entire starter and sanitize the jar before starting again.

Normal Starter Behavior

Totally normal things:

Bubbles
Slight separation
A strong sour smell
A layer of hooch
Rising and falling

Starters are active cultures — they aren’t meant to look sterile.

5 Things You Can Make With Discard

Sourdough pancakes or waffles
Pull apart garlic bread
Biscuits
Banana bread
Noodles

Discard adds flavor, tenderness, and depth — without needing a full rise.

How to Dehydrate Your Starter (Backup Insurance)

Every sourdough baker should do this once.

It takes 10 minutes and gives you peace of mind.

To Dehydrate:

Feed your starter and let it become active.
Spread a thin layer on parchment paper.
Let it air dry completely (24–48 hours).
Break into flakes.
Store in an airtight jar.

No heat needed — just room temperature.

To Rehydrate:

Weigh 10 g dried starter flakes (0.35 oz).
Add 10 g warm water.
Let sit until softened.
Feed 1:1:1.
Repeat feedings for a few days until active.

It comes back surprisingly well.

Tools That Make This Easier

A digital kitchen scale removes all the guesswork.

There are also sourdough starter kits available that include:

A marked jar
Cloth cover
Thermometer
Feeding ratio guides
Spatulas and scrapers

They make the math much simpler if you’re just starting out. Extra simple if you also get a kitchen scale.

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Final Thoughts

You don’t need to overcomplicate sourdough.

Feed it.
Use it.
Store it in the fridge.
Revive it when needed.
Dry some as backup.

Starters are resilient. Much more than we give them credit for.

If you bake 1–2 times per week like I do, the fridge method keeps everything simple and sustainable.

And once you understand the ratios — it stops feeling intimidating.

It just becomes part of your rhythm.