How to Make a Sourdough Starter from Scratch
A simple, accurate day-by-day method, plus a feeding-ratio helper, maintenance and troubleshooting.
A sourdough starter is a live culture of wild yeast and lactic bacteria, grown from nothing more than flour and water. Those microbes are already present on the flour and in the air of your kitchen. When you feed them a steady supply of flour and water, they wake up, multiply, and begin to ferment. The yeast produces the gas that makes bread rise, and the bacteria produce the acids that give sourdough its flavor and keeping quality.
It works because you are not adding anything exotic. You are simply building a stable home for wild microbes and feeding them on a routine until they are strong and predictable. From a cold start it usually takes about 5 to 10 days to establish a starter that rises reliably and is ready to bake with. Once it is going, it can live in your kitchen for years.
This is a homestead-kitchen staple in the same family as preserving. A jar of starter on the counter turns a bag of flour into bread, crackers and pancakes, and it costs almost nothing to keep alive.
What You Need
Keep it simple. A starter needs flour, water, a container and a way to weigh things accurately.
- Flour. Whole wheat or rye flour is the best way to start, because it carries more wild microbes and minerals and gets things moving faster. After the first few days you can switch to all-purpose or bread flour, or keep a whole wheat blend. Either way, an unbleached flour works best.
- Non-chlorinated water. Chlorine in tap water can slow the wild microbes. If your tap water is chlorinated, let it sit in an open pitcher for a few hours so the chlorine dissipates, or use filtered or bottled water. Room temperature, never hot.
- A jar. A clean glass jar of about 2 to 4 cups (500 mL to 1 liter) is ideal. Rest the lid on loosely or use a cloth and band, so gas can escape. Never seal it tight.
- A scale. A simple kitchen scale is the single biggest help. Sourdough is much easier when you work by weight in grams rather than by volume, because flours pack differently and accuracy keeps your feeds balanced. The amounts here are given in grams, with rough cups as a backup.
Day-by-Day Method
This is the standard, reliable method. Use equal weights of flour and water and feed once a day. A small starter is easier to manage and wastes less flour.
| Day | What to do | What you should see |
|---|---|---|
| Day 1 | Weigh 50 g whole wheat or rye flour and 50 g water into the jar. Stir to a thick paste. Rest the lid on loosely and leave in a warm spot, ideally 72 to 79 degrees Fahrenheit. | Nothing yet. This is normal. |
| Day 2 | Stir. If there is little or no activity, simply leave it for another day without feeding, or begin the daily routine below. | Sometimes an early burst of bubbles. This is often the wrong microbes and will settle. Do not be fooled into thinking it is ready. |
| Days 3 to 7 | Once a day, discard most of the starter so about 50 g remains, then feed 50 g flour and 50 g water. Stir, loosely cover and return to the warm spot. This is the 1:1:1 feed by weight. | Bubbles through the mixture, a pleasant sour or yogurt-like smell, and the starter rising then falling between feeds. Activity may surge, go quiet, then return stronger. |
| Day 7 onward | Keep feeding daily until it is reliably active. Test it before baking with it. | The starter consistently doubles within 4 to 8 hours of a feed and passes the float test. |
The 1:1:1 feed explained
A 1:1:1 feed means equal weights of starter, flour and water. Keep 50 g of starter, add 50 g flour and 50 g water. Discarding most of the old starter before each feed matters: it keeps the jar a manageable size and gives the microbes a fresh, generous supply of food rather than diluting them into a tired, acidic mix.
How to know it is ready
Your starter is ready to bake with when two things are true. First, it reliably rises to roughly double its volume within 4 to 8 hours of feeding, then slowly falls. Second, it passes the float test: drop a small spoonful of risen starter into a glass of water and it floats, because it is full of gas. A young starter that bubbles but does not yet double needs more days of feeding.
Feeding-Ratio Helper
Tell the helper how much starter you want to keep, and it works out the three common feeds by weight. The 1:1:1 is the everyday counter feed. The 1:2:2 and 1:5:5 give the microbes more food, so they take longer to peak, which suits a slower schedule or a starter that has been in the fridge. All amounts are equal flour and water by weight, so they are the same whatever flour you use, with rough cups shown as a backup.
Work out your feed
Each card shows how much flour and water to add to the starter you keep, and the total weight you will end up with. Cups are approximate. Discard or use any extra starter before you feed.
Maintaining Your Starter
Once your starter is established, you choose how often to feed it based on how often you bake.
- Daily on the counter. If you bake often, keep it at room temperature and feed it once or twice a day with a 1:1:1 feed. A counter starter is at its most active and ready to bake at short notice.
- Weekly in the fridge. If you bake occasionally, store it in the fridge. The cold slows everything down, so it only needs feeding about once a week. To bake from a fridge starter, take it out and give it one or two room-temperature feeds first so it wakes up and gets lively again.
Reviving a neglected starter
Most starters are tougher than they look. If yours has been forgotten in the fridge for weeks and has a layer of liquid and a sharp smell, it is usually still alive. Pour off any liquid, discard all but a tablespoon, and feed it 1:1:1. Repeat once or twice a day at room temperature. Within a day or two it should be bubbling and rising again. Only give up if you see actual mold.
Hooch, the gray liquid
A thin gray or clear liquid on top is called hooch. It is alcohol produced by hungry yeast and it is a sign your starter wants feeding more often, not a sign it has gone bad. You can stir it back in for a slightly tangier result, or pour it off before feeding. Either is fine.
Troubleshooting
Not rising
The usual causes are cold, youth and underfeeding. Move the jar somewhere warmer, around 72 to 79 degrees Fahrenheit, keep feeding daily, and give it time. Many starters are quiet for the first few days, then build steadily by day 5 to 7. As long as there is no fuzzy mold, keep going.
Smells like nail polish or acetone
A sharp solvent or nail polish smell means the starter is hungry and has run out of food. It is not spoiled. Feed it more often, or feed a larger ratio such as 1:5:5 to give it more to work with, and the smell will settle back to a pleasant sour tang within a feed or two.
Mold, when to discard and start over
Too sour
An overly sour starter is simply over-fermented and acidic. Feed it more often, use a larger feed ratio like 1:5:5, keep it a little cooler, and use it closer to its peak rise rather than after it has fallen. A milder, sweeter starter follows within a few feeds.
Using It
Once your starter is lively, you have a free, renewable leaven for the kitchen. The starter you discard at each feed does not have to be wasted. Stir it into pancakes or waffles, or roll it thin with a little oil and salt and bake it into crisp sourdough crackers. These discard recipes are a great way to use the culture while it is still building.
This guide is about the starter itself, the part most people find fiddly. Turning it into a loaf is the next step: a basic sourdough bread comes down to mixing your active starter with flour, water and salt, building strength with folds, a long slow rise, then baking. Keep the starter healthy and the baking gets easy.
A jar of bubbling starter sits right alongside a shelf of preserves and a worm bin in the homestead picture. It is the same idea as preserving the harvest: take a simple raw ingredient, work with natural processes, and turn it into something that feeds you for a long time. It is one of the cheapest, most satisfying steps toward a self-sufficient kitchen.
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Open the App →Frequently Asked Questions
How long does it take to make a sourdough starter?
Most starters become active and bakeable in 5 to 10 days. You will usually see the first bubbles around day 3 to 5. The starter is ready once it reliably doubles within 4 to 8 hours of a feed and passes the float test. Warm kitchens speed this up, cool ones slow it down.
Why is my sourdough starter not bubbling?
Most often it is too cold, too young, or underfed. Move it to a warmer spot around 72 to 79 degrees Fahrenheit, keep feeding it daily, and be patient through the first few days. Many starters surge with activity around day 2 to 3, go quiet, then come back stronger by day 5 to 7. As long as there is no fuzzy mold, keep going.
Can I use tap water for a sourdough starter?
Yes, as long as it is not heavily chlorinated, because chlorine can slow the wild microbes. If your tap water is chlorinated, leave it in an open pitcher for a few hours so the chlorine can dissipate, or use filtered or bottled water. Avoid hot water, which can kill the culture. Room temperature water is best.
How often should I feed my sourdough starter?
While you are establishing it, feed once a day. A mature starter kept on the counter is usually fed once or twice a day. If you keep it in the fridge, feed it about once a week. Always discard most of the starter before each feed so the fresh flour and water are not overwhelmed.
Should I keep my sourdough starter on the counter or in the fridge?
Keep it on the counter if you bake often, as a daily-fed starter at room temperature is at its most active. Keep it in the fridge if you bake occasionally, where it slows right down and only needs feeding about once a week. To bake from a fridge starter, take it out and give it one or two feeds at room temperature first.
What is the float test?
The float test checks whether a starter is active enough to leaven bread. Drop a small spoonful of recently fed, risen starter into a glass of water. If it floats, it is full of gas and ready to use. If it sinks, give it more time or another feed. It is a useful guide rather than a perfect rule, so also look for a starter that has roughly doubled and is full of bubbles.
My starter smells like nail polish or acetone, is it ruined?
No. A sharp solvent or nail polish smell means the starter is hungry and has run out of food. It is not spoiled. Feed it more often, or feed it a larger ratio such as 1 part starter to 5 parts flour and 5 parts water, and the smell will settle back to a pleasant sour tang within a feed or two.
When should I throw a sourdough starter away?
Throw it out and start again if you see fuzzy mold of any color, or pink, orange or red streaks, which signal harmful contamination. A gray or clear liquid on top, called hooch, and a strong sour or solvent smell are normal and fixable. Mold is not. When in doubt about mold, do not taste it, discard the whole jar, wash it well and begin a fresh starter.
See also: Preserving the Harvest and Homemade Feeds and Sprays