Sourdough Basics

What is a sourdough starter?

A starter is a community of wild yeast and friendly bacteria living in flour and water. The yeast makes gas that lifts the dough, and the bacteria produce acids that give the bread its tang and help it keep longer.

You can begin a starter by mixing flour and water and feeding it regularly, or by getting some from a friend or neighbor. A shared starter often gets going faster.

The word sourdough covers many styles, from tangy to mild. Flavor depends on flour, water, temperature and how often you feed the starter.

• Keep it fed on a schedule
• Keep it clean and covered loosely
• Keep notes on how it behaves

How do you make and feed a starter?

To create one, mix flour and water in a clean jar, cover loosely, and feed on a regular schedule by discarding some and adding fresh flour and water. It takes days to become active, and early stages can smell odd or look quiet before it takes off.

Once active, the starter rises and falls predictably after a feeding. Feed it often at room temperature, or keep it in the refrigerator and feed it less often. Instructions from a tested baking source will give you ratios and timing.

• Use a clean jar and a loose cover
• Feed on a regular schedule
• Refrigerate when you bake less often
• Wake a chilled starter with a feeding or two before baking

How do you know a starter is ready?

A ready starter doubles in a reasonable time after a feeding, shows bubbles throughout, and smells pleasantly tangy or yeasty. A common test is whether a spoonful floats in water, though it is not perfect.

Do not rely on one sign. Look at rise, bubbles and smell together, and keep track from day to day.

Keep a simple log with the date, feeding amounts and how high the starter rose. A pattern appears within a week or two and helps you plan baking days.

What does a first loaf involve?

A basic sourdough loaf mixes starter, flour, water and salt, rests, is folded a few times, rises slowly, is shaped, and is baked in a hot oven. The long, slow rise builds flavor and structure, and the timing flexes to fit your day.

Cold room temperatures slow everything, and warm ones speed it up. Learn to judge by how the dough looks and feels, not just by the recipe clock.

Plan your timing backward from when you want to bake. Many people mix in the evening, shape in the morning and bake in the afternoon, using a cool spot or the refrigerator to hold the dough.

What problems are common?

A starter that is slow is usually cold, hungry or fed with chlorinated water in some cases, so try warmer conditions, more frequent feeding or a different water source. A layer of dark liquid on top is hunger. Stir it in or pour it off and feed.

Pink or orange streaks, fuzzy mold or a truly foul smell mean the starter has spoiled and should be discarded. Start fresh with a clean jar rather than risk eating it.

Wash the jar from time to time, because dried bits on the glass can grow mold. Move the starter to a clean jar if you see any.

• Hooch, the gray liquid layer, means hungry, not spoiled
• Pink, orange or fuzzy growth means discard
• Warm spots speed a slow starter

What do you do with discard?

Discard is the portion removed when feeding. It can go into pancakes, crackers, flatbreads and muffins. Using it reduces waste and keeps flour costs down.

If you bake rarely, keep the starter small and refrigerated. A small amount fed less often is enough.

How do you keep learning?

Bake the same loaf several times before changing the recipe. Notes on flour, water temperature, rising time and results will teach you what your own starter does. A neighbor with experience is worth more than a dozen videos.

If anyone in your household has a gluten condition, talk to a doctor or dietitian, because sourdough is not gluten-free unless made with gluten-free flour.

Last reviewed: November 12, 2026. Written by the Rural Farm Life Editorial Team. See our editorial policy.