How to build a sourdough starter from scratch

A sourdough starter is a living culture of wild yeasts and lactic acid bacteria. Once fed regularly, it captures airborne and flour-borne microbes, producing the gas and acidity that make bread rise and develop flavour. Unlike a commercial yeast sachet, a starter is maintained over time and can become a dependable part of a home kitchen routine.

Building one takes patience rather than specialist equipment. A small quantity of flour and water is combined, then discarded and refreshed each day while the culture strengthens. Visible activity may appear within several days, although a cool kitchen can take longer than a warm one. A new starter can smell yeasty, grassy or faintly sour before it is ready to leaven dough.

The flour changes how quickly the culture develops and how the finished bread tastes. Plain supermarket flour creates a mild starter, while strong white flour gives it strength and wholemeal encourages vigorous activity. Because Australian kitchens span very different seasons, temperature matters at least as much as the recipe. Treat the feeding ratio as a flexible system rather than a fixed timetable.

Clean tools, a ventilated jar and consistent measurements are the practical foundations. Keep the culture away from persistent mould, and discard the entire mixture if coloured or fuzzy growth appears. Once the starter doubles reliably and smells pleasantly tangy, it can be used for bread, pancakes, crumpets or lighter discard-based recipes.

Flour	Typical Australian protein	Starter behaviour	Best fit
Plain flour	8–9%	Mild aroma and moderate activity	Economical starter and everyday loaves
Strong white or bread flour	11–13%	Strong rise and resilient dough	Beginner sourdough and open-crumb bread
Wholemeal	11–13%	Quick, tangy activity	Robust starter and rustic loaves
White wholemeal	10–12%	Milder than wholemeal	A balance of flavour and colour

Choose Australian flour and water

Coles, Woolworths and independent bakeries generally stock plain, strong and wholemeal wheat flour. Plain flour is affordable and mild, strong flour has more protein for better dough structure, and wholemeal adds bran that feeds bacteria quickly. For people sourcing from local sellers rather than supermarkets, Market Up’s Australian buying guides can help compare available products before committing to a large bag.

Tap water is usually suitable, although filtered water is a sensible choice if your local supply has a strong chlorine taste. Keep the flour and water at roughly the same temperature, ideally between 24°C and 27°C. A Melbourne kitchen may sit below 20°C in winter, while a Brisbane bench can exceed 28°C in summer. Sydney’s humidity often matters more during dough proofing than during starter maintenance.

Australian recipes benefit from accurate metric measurements, so a small kitchen scale is more useful than relying on volume. Weigh flour, water and starter every time, especially while learning how the culture responds to different flour. Wholemeal can make a starter expand rapidly but produces a more acidic smell; mixing it with strong white flour often gives beginners a balanced and forgiving culture.

Mix and begin the culture

Combine 50 grams of flour with 50 grams of lukewarm water in a clean 250-millilitre container. Stir until no dry flour remains, cover with a loose lid or cloth, and secure it with a rubber band. Mark the starting level with a pen so expansion is easy to see. Avoid a tightly sealed jar because fermentation produces carbon dioxide.

The container does not need to be sterile, but it should be washed with hot soapy water and rinsed before every new batch. Keep it away from direct sunlight, excessive heat and household chemicals. A daily reminder helps because early feeding often produces little visible change. During those quiet intervals, IllusiDuniawi’s curated lifestyle stories can provide light reading without distracting from the routine.

Expect the first day to look much like thin paste. By day two, there may be small bubbles, a slightly domed surface or a sharper smell. Discard all but about 50 grams of the mixture, then add 50 grams of fresh flour and 50 grams of water. Repeat this process daily until the starter rises reliably and smells pleasantly yeasty rather than aggressively sour.

Feed the starter and watch its signals

A simple equal-parts feed works well for most home bakers. Place 50 grams of active starter in a clean container, add 50 grams of flour and 50 grams of water, then stir and mark the level. If the culture is especially lively, a one-to-two-to-two ratio—10 grams starter, 20 grams flour and 20 grams water—can keep it vigorous while using less discarded starter.

A useful rise test uses 50 grams of starter, 100 grams of flour and 100 grams of water. The mixture should roughly double within four to six hours at room temperature. Bubbles along the sides and a domed top are stronger indicators than a floating test, which can be unreliable. If it barely moves, continue feeding daily for several more days rather than rushing the process.

A layer of clear or cloudy liquid can form above the culture; this is alcohol produced during an overly long period between feeds. Pour it away, then feed the remaining starter. Any pink, orange, green or black fuzzy growth calls for disposal of the entire batch, not careful scraping. When troubleshooting becomes visual, the fresh visual perspectives at Seeing New Data can complement close observation of bubbles, texture and colour.

Turn the starter into a first loaf

For a straightforward loaf, combine 100 grams of active starter with 500 grams of strong white flour, 375 grams of water and 10 grams of fine salt. This creates roughly 71% hydration when the flour and water already present in the starter are included. Mix the starter with most of the water, rest for 30 minutes, then add the flour, salt and remaining water. Perform several sets of folds during the first two hours.

Let the dough prove until visibly puffy and capable of holding a partial shape. Melbourne ovens and rooms may require a longer proof, while Brisbane kitchens can move quickly, especially in summer. Sydney bakers often find that humid conditions keep dough softer but make shaping more delicate. Bake in a preheated lidded casserole at 240°C for about 20 minutes, then remove the lid and reduce the temperature to 220°C for another 20 to 25 minutes.

An oven thermometer is worthwhile because domestic temperatures vary considerably. Let the loaf cool before slicing so the crumb can set. Sourdough also travels well: while planning a trip, compare photogenic travel streets and look for local bakeries serving naturally leavened bread. Their methods can provide useful reference points when adjusting your own hydration and fermentation times.

Maintain the culture and remember its value

Store an active starter in a clean jar with a loose lid, then feed it once daily when the kitchen is warm or every two or three days when it is cool. During a Melbourne winter, a refrigerated feed every two days may be more practical. In Brisbane heat, smaller feeds and shorter intervals can prevent the culture from becoming overly acidic. Refresh it thoroughly before returning it to the refrigerator.

Home baking for personal use has different obligations from selling food. If bread or starter is packaged for sale, Food Standards Australia New Zealand requirements apply to ingredient lists and mandatory allergen declarations, including wheat. State council licensing and food-business rules also vary, while the Australian Consumer Law prohibits misleading claims. Online side projects require equally clear disclosure of paid relationships, a commercial principle illustrated by affiliate program updates.

The lasting lesson is that a sourdough starter is not a one-time mixture but a small biological partnership. Feed it with measured flour and water, adjust the schedule to the local temperature, and watch its behaviour rather than relying on a fixed calendar. Its strength comes from consistency: once kept alive and used while lively, it rewards attention with dependable rise, complex flavour and bread that reflects the baker’s own kitchen.