Starting a sourdough starter at home is surprisingly simple. With just flour, water, and a little patience, you can create a living culture that will raise bread, pancakes, waffles, and more for years.

This guide walks through everything you need to know to start, feed, store, and troubleshoot a sourdough starter in a home kitchen.

What Is a Sourdough Starter?

A sourdough starter is a mixture of flour and water that has been colonized by wild yeast and lactic acid bacteria. These microorganisms:

  • Eat sugars in the flour
  • Produce gas (which makes dough rise)
  • Create acids (which give sourdough its tangy flavor and help preserve the bread)

Once established, a starter is like a low-maintenance pet: feed it regularly and it will keep working for you indefinitely.

Tools and Ingredients You’ll Need

You don’t need anything fancy to get started. Here’s a simple list:

  • Flour – All-purpose or bread flour works; many bakers like to start with whole wheat or rye for extra activity
  • Water – Room temperature, non-chlorinated if possible (filter or let tap water sit out for a few hours)
  • Container – Glass jar or clear plastic container (about 16–32 oz / 500–1000 ml)
  • Scale (preferred) – A digital kitchen scale makes feeding more precise
  • Spoon or spatula – For mixing
  • Loose cover – Lid set on top, coffee filter, or clean cloth with a rubber band (you want to keep dust out but still allow air to escape)

Optional but helpful:

  • Rubber band or tape to mark the starter’s level
  • Second container for clean transfers once in a while

Basic Ratios: By Weight and By Volume

Starters are most often kept at 100% hydration, which means:

  • Equal parts flour and water by weight, e.g.
    • 50 g flour + 50 g water
    • 75 g flour + 75 g water

If you don’t have a scale, approximate by volume:

  • 1/2 cup flour
  • A scant 1/2 cup water (you want a thick, pourable batter)

The exact thickness can vary a bit. Think pancake batter: not soup-thin, not dough-stiff.

Step-by-Step: Creating Your Starter (Days 1–7)

This is one simple, reliable approach. Room temperature is assumed to be around 68–75°F (20–24°C).

Day 1

  1. In your jar, mix:
    • 50 g (about 1/3–1/2 cup) flour
    • 50 g (about 1/4–1/3 cup) water
  2. Stir until no dry flour remains.
  3. Scrape down the sides, loosely cover, and leave at room temperature for 24 hours.

It may look boring today. That’s fine.

Day 2

  1. You may or may not see small bubbles. Either way, stir well once or twice during the day to mix in oxygen.
  2. In the evening (or after 24 hours), feed it:
    • Discard roughly half of the mixture (you can throw it away at this point).
    • Add 50 g flour + 50 g water, stir, and cover again.

Days 3–4

You should start seeing some activity:

  • Bubbles on the surface or sides of the jar
  • A slightly tangy or fruity smell
  • The starter rising somewhat between feedings

Continue a once-a-day feeding:

  1. Stir down the starter.
  2. Discard all but about 50 g (roughly 1/4 cup).
  3. Add 50 g flour + 50 g water.
  4. Mix, mark the level with a rubber band, and cover.

Days 5–7

By now, the starter may be rising noticeably—sometimes doubling in volume between feedings.

Shift to twice-a-day feedings if it’s very active and your kitchen is warm:

  • Morning: Discard down to 50 g, then feed 50 g flour + 50 g water.
  • Evening (about 12 hours later): Repeat the discard and feed.

You’ll know your starter is ready to bake when, after a feed, it:

  • Rises to at least double in size within 4–8 hours
  • Smells pleasantly yeasty, tangy, or slightly fruity
  • Has lots of bubbles throughout, not just on top

This usually takes 5–10 days, but exact timing varies with temperature and flour.

How to Feed and Maintain a Mature Starter

Once your starter is active and reliable, you can keep it going with very little effort.

Room-Temperature Routine

Keep your starter on the counter if you bake frequently (daily or almost daily). A simple daily routine:

  1. Stir down the starter.
  2. Discard all but about 25–50 g.
  3. Feed at least an equal amount of flour and water, e.g.:
    • 50 g starter
    • 50 g water
    • 50 g flour

If your kitchen is warm or the starter is very active, you may need twice-daily feedings at room temperature to prevent it from getting too hungry and sour.

Fridge Routine (Low-Maintenance)

If you bake once a week or less, the refrigerator is your friend:

  1. Give your starter a normal feeding.
  2. Let it sit at room temperature for 1–2 hours to start waking up.
  3. Cover and place it in the fridge.

In the fridge, you can usually feed:

  • Once a week if using regularly
  • Every 2 weeks if you’re occasionally baking

When you’re ready to bake:

  1. Remove the starter from the fridge.
  2. Stir and discard down to about 25–50 g.
  3. Feed as usual and let it warm and rise at room temp.
  4. If it’s sluggish, give it 2–3 room-temperature feedings (12 hours apart) before using it in dough.

Using and Saving “Discard”

Every feeding creates discard, the portion you remove before adding fresh flour and water. Discard is necessary to keep your starter from growing uncontrollably, but it doesn’t have to be waste.

You can use discard in recipes where you don’t rely on its rising power, such as:

  • Pancakes or waffles
  • Crackers or flatbreads
  • Muffins, quick breads, or banana bread
  • Pizza dough (with added yeast)
  • Biscuits and scones

Store discard in a jar in the fridge for up to a week or so, and use it in recipes that call for “sourdough discard.”

Signs of a Healthy Starter

A healthy, happy starter usually:

  • Rises and falls predictably after feedings
  • Smells pleasantly tangy, yeasty, or slightly fruity
  • Has a bubbly, airy texture
  • Forms strands and webs when you pull some up with a spoon

Over time, you’ll get to know your starter’s “personality”: how fast it rises, what it smells like when hungry, and when it’s at peak strength.

Troubleshooting Common Problems

Don’t panic—starters are tougher than they look. Here are common issues and how to fix them.

It Smells Like Nail Polish Remover or Solvent

This often means the starter is underfed or has been sitting too long between feedings.

Fix:

  • Give it a couple of feeds in a row at room temperature.
  • Discard heavily (keep just a spoonful) and rebuild with fresh flour and water.
  • Keep your feeding schedule more regular.

There’s a Gray/Brown Liquid on Top (Hooch)

That liquid is called hooch, a sign that your starter is hungry. It’s usually harmless.

Fix:

  • Stir the hooch back in for more sour flavor, or pour it off for a milder taste.
  • Feed the starter more often or increase the feed size.

It’s Not Rising Much

Common causes:

  • Temperature too low
  • Not enough feed or irregular feedings
  • Very new starter that needs more time

Fix:

  • Move the starter to a warmer spot (70–78°F / 21–26°C is ideal).
  • Feed more consistently for a few days.
  • Try a couple of feeds with whole wheat or rye flour to boost activity.

There’s Mold or Colored Streaks

If you see:

  • Pink, orange, green, black, or fuzzy growth
  • Strong rotten or putrid smells

It’s safest to throw it out and start over. Mold usually means contamination, and it’s not worth salvaging.

To reduce the risk next time:

  • Use a clean container and spoon.
  • Avoid letting food particles or other ingredients get into the jar.
  • Keep the lid loose but not wide open.

Adjusting Flour Types and Hydration

Once your starter is stable, you can customize it.

  • Flour type: Switch gradually by feeding with a different flour (e.g., from all-purpose to whole wheat). Over several feedings, the starter will adapt to the new flour.
  • Stiffer starter: Use more flour than water (e.g., 100 g flour + 60 g water) for a dough-like starter. This ferments more slowly and can be easier to handle.
  • Looser starter: Use a little more water for a very soft, batter-like starter. This can ferment faster.

Changes in flour and hydration will affect flavor, speed, and how your dough behaves, so make notes and adjust according to what you like.

A Simple Weekly Routine Example

Here’s one low-fuss routine if you bake once a week:

The day before baking:

  1. Take starter out of the fridge in the morning.
  2. Discard down to 25–50 g and feed 50 g water + 50 g flour.
  3. Let it rise at room temp.
  4. In the evening, if it has peaked and fallen, feed once more.

Baking day:

  1. Use the active starter for your dough when it’s near its peak rise.
  2. After measuring out what you need, feed what’s left in the jar.
  3. Let it sit for 1–2 hours at room temp and then put it back in the fridge.

Repeat weekly.

Final Thoughts: Don’t Overthink It

Sourdough can look complicated from the outside, but the core idea is simple:

  • Mix flour and water
  • Feed it regularly
  • Use it when it’s lively and bubbly

Your starter doesn’t have to be perfect to make good bread. Treat it like a living, forgiving roommate rather than a fragile science project. With a few weeks of practice, feeding and baking with your starter will become just another comfortable kitchen habit.