How to Make Sourdough Starter: Feeding, Readiness and Care

Make sourdough starter by combining flour and water, then repeatedly keeping a small portion and feeding it fresh flour and water until it rises predictably. You are building a living culture, not making a loaf on the first day. The most useful beginner habit is keeping a simple feeding record: what you added, when you added it, and how much the mixture rose afterward. That turns an unfamiliar jar of bubbles into something you can understand.

What you need before starting

Choose a clean, clear container with plenty of room above the mixture, a kitchen scale, a spoon or spatula, and a loose-fitting cover. Clear sides help you compare the level immediately after feeding with the level later. Use food-safe glass, plastic or stainless steel; avoid reactive metals such as uncoated copper or aluminum. Ordinary drinkable tap water usually works, and you do not need an expensive jar or a famous old culture. King Arthur’s sourdough myth guide explains why neither special water nor a starter’s impressive age guarantees better bread. Put the container somewhere you will remember it. Our practical suggestion is to keep a notebook beside the flour rather than trusting your memory about the last feeding. Label the jar with its start date and use an external rubber band or removable mark to show the freshly mixed level.

A small-batch feeding schedule

This schedule summarizes King Arthur’s starter method. Use a loosely covered, nonreactive ½- to 1-quart container, kept around 70°F (21°C). Mix thoroughly, leaving no dry flour.

Day 1	50 g whole-wheat flour + 50 g water; rest 24 hours
Day 2	Keep 50 g starter; add 50 g all-purpose flour + 50 g water. Rest 24 hours.
Day 3 onward	Repeat that feeding about every 12 hours. Remove the excess before each feeding.
Readiness	Reliably doubles within about 6–8 hours after feeding, with plentiful bubbles and a pleasant tangy smell.
If not ready	Continue the feeding cycle; day five is not a deadline.

Weigh the ingredients. Equal weights of flour and water do not mean equal cup measures. Each standard feeding leaves 150 g total: 50 g retained starter plus 50 g flour plus 50 g water. Keeping all the old mixture while adding the same small feeding changes the ratio.

Why an exciting early rise can disappear

A new starter may puff up impressively and then seem to stop. That is not automatically evidence that you ruined it. During the early days, the microbial community is changing as the mixture becomes more acidic. An initial burst can fade before a stable culture develops. King Arthur describes this early false start and advises looking for predictable rising and falling after continued feeding. Keep following one method rather than switching flour, water quantity and feeding intervals all at once. A single large bubble or one dramatic overnight expansion is a weak basis for planning a loaf. Compare several feedings in your notes. Record a quiet day as a quiet day, not as a diagnosis. This patience advice applies to a normal-looking culture; visible mold or unusual pink or orange growth is a separate problem addressed below.

How to judge readiness without relying on a float test

Watch the culture in its container. Mark the starting height after mixing, note the time, and check later without stirring it down. You want a repeatable pattern of expansion, bubbles throughout and a pleasantly acidic aroma. Do not taste it. The popular test of dropping a spoonful into water is not a dependable shortcut: a sample can float before the culture is ready to raise bread. King Arthur recommends tracking growth instead. Also compare like with like. A stiff starter made with less water looks different from the batter-like method here, and a photograph of someone else’s jar cannot establish that yours is ready. In your record, “rose from the mark to twice its height after the morning feeding” is more useful than “looks about right.” Photograph your own jar from the side at consistent intervals if that makes the change easier to see.

Clean handling and signs that mean start over

Flour is a raw ingredient, so starter is not a food to taste before cooking. Wash your hands, clean the work surface and use clean utensils. Keep the container loosely covered to reduce contamination while allowing fermentation gas to escape. Colorado State University Extension’s starter guidance emphasizes both regular feeding and safe handling. If you see fuzzy or colored mold, discard the entire starter and thoroughly clean and rinse the container before beginning again. Do not scrape off the visible patch and save what is underneath. A liquid layer with an alcoholic smell can be a fermentation byproduct rather than mold, but it is not a reason to ignore other signs of spoilage. If you cannot confidently distinguish normal liquid from suspicious growth, replacing a small starter is a better choice than trying to rescue an uncertain culture.

King Arthur’s sourdough FAQ also identifies pink or orange discoloration and an abnormal odor as reasons to throw a starter away. Keep this decision separate from whether a healthy-looking starter happens to be slow. More feeding is not a remedy for visible contamination.

Once established, choose a maintenance routine

After the culture is reliably active, your baking frequency can guide storage. King Arthur’s maintenance method offers a daily room-temperature feeding or approximately weekly feeding for a refrigerated starter. For refrigeration, keep 50 g starter, feed 50 g flour and 50 g water, let it stand at room temperature for 1–2 hours, then refrigerate. Before baking, give it room-temperature feedings until it again rises reliably; taking a cold jar out of the fridge does not instantly make it ripe. Set aside a portion to maintain before using the rest in a recipe. That small habit prevents the disappointing discovery that your entire starter went into the dough. Follow a recipe written for sourdough starter rather than replacing packaged yeast with a random spoonful: starter contributes both flour and water as well as leavening, so the dough formula changes.

Troubleshooting without changing everything at once

If progress is slow, check the actual room conditions and your measurements before adding extra ingredients. A cool spot slows fermentation. A cover that lets too much moisture escape can leave the surface drying out. An Extension response on slow starter development notes that some cultures can take up to two weeks and recommends attention to warmth and the container cover. Use a loose lid rather than leaving the jar exposed. Avoid setting it in an oven that someone might turn on; a stable spot on the counter is easier to manage safely. For each feeding, write down the retained starter weight, new flour and water weights, room temperature if available, and the time. If you ask an experienced baker for help, those details are far more informative than a photograph alone.

What to bake while your starter develops

You do not need to rush the culture to enjoy homemade bread. Our beginner white-bread guide uses packaged yeast and teaches kneading, shaping and cooling. Our pizza dough guide offers another way to practice handling dough. Treat those as separate recipes, not as instructions to add commercial yeast to this starter. For this project, the goal is a repeatable feeding routine and a dependable culture; the first sourdough loaf comes afterward.

Sources and image notes

The feeding schedule is based on the linked King Arthur starter recipe; maintenance, readiness and troubleshooting sources are linked beside the advice they support. Food-handling guidance comes from Colorado State University Extension. The seven photographs are licensed examples from different bakers, not a continuous test of this method. Two images show a deliberately stiffer culture for comparison. Creator and license links appear in every caption.