How to Make a Sourdough Starter from Scratch and Keep It Alive

A sourdough starter is a living culture of wild yeast and lactic acid bacteria made from flour, water, time, and a little patience. Once it is established, it can leaven bread, deepen flavour in pancakes, enrich crumpets, and turn everyday baking into something with far more character. The process is simple, although the culture will behave differently depending on your flour, room temperature, water, and the season.

For Australian home cooks, the biggest variable is often climate. A starter may race ahead during a humid Brisbane summer, while one in a cool Melbourne kitchen can take several days to become reliably active. Treat the timetable as a guide rather than a rule, and learn to read the signs: bubbles, a clean pleasantly sour aroma, and a rise that repeats after feeding.

What You Need To Begin

Use a clean glass jar with plenty of room for expansion. A 750 ml jar is a practical size for a small household starter, and a rubber band placed around the jar at the starting level makes rising easy to track. Cover the opening loosely with a lid, cloth, or reusable cover. The culture needs protection from dust and insects, but it should not be sealed tightly while fermentation is active.

Begin with wholemeal rye or wholemeal wheat flour if you can find it. The outer parts of the grain contain minerals and microorganisms that help a new culture get moving. Australian supermarkets such as Coles and Woolworths usually carry wholemeal flour, while independent grocers, organic shops, and specialist mills may offer rye flour or freshly milled options. A plain white bread flour can be introduced later once the starter is vigorous.

Place the jar somewhere stable and out of direct sunlight. Around 22–26°C is comfortable for fermentation, though your starter can work outside that range. In a hot Queensland kitchen, keep it away from the oven and consider using cooler water. During a chilly Southern Highlands or Tasmanian winter, a cupboard or switched-off microwave may provide a steadier environment.

A Simple Feeding Routine

On the first day, mix 50 grams of wholemeal flour with 50 grams of water. Filtered water is useful if your tap water has a strong chlorine smell, since chlorine can slow microbial activity. Stir until no dry patches remain, scrape down the sides, cover loosely, and leave it for 24 hours.

On day two, you may see a few bubbles, a thin liquid layer, or no visible change at all. Discard half the mixture, then feed the remainder with 50 grams of flour and 50 grams of water. Removing some culture prevents the jar from becoming enormous and keeps the balance of flour, water, yeast, and bacteria manageable.

Repeat this process every 24 hours. Once the starter begins rising and falling within a predictable period, switch to a smaller maintenance quantity: retain 25 grams of starter and add 50 grams of water and 50 grams of flour. This creates a 1:2:2 feeding ratio by weight. A digital scale is far more reliable than cups because flour compresses differently from one scoop to the next.

A young starter can appear lively on the second or third day, then go quiet. This false burst is normal and does not mean the culture is ready. Continue feeding patiently until it rises after each refreshment and smells pleasantly tangy, fruity, yoghurty, or mildly yeasty rather than harsh or rotten.

How To Tell When It Is Ready

A mature sourdough culture should double in volume within roughly four to eight hours of feeding, depending on temperature and the flour used. It should have bubbles throughout the mixture, a domed or slightly rounded surface at its peak, and a network of air pockets visible against the glass. The strongest test is repetition: it should perform this way for several feedings in a row.

The popular float test can offer a clue but should not be treated as a final verdict. Drop a small spoonful of recently fed starter into water. If it floats, enough gas may be trapped inside to leaven dough. If it sinks, the culture could simply be young, hungry, or past its peak. Timing, rise, aroma, and texture tell you more than the float test alone.

A sharp acetone smell usually means the starter is hungry. Feed it more often, or increase the amount of fresh flour and water in relation to the old culture. A greyish liquid on top, called hooch, is another sign that the culture has used up its food. Stir it in for extra acidity or pour it off before feeding if the smell is particularly strong.

Discard the starter if you see fuzzy mould or pink, orange, or red streaks. These indicate unwanted contamination. A dark, dry crust around the jar is usually harmless if the inside looks healthy, but keeping the sides clean makes the culture easier to inspect and reduces the chance of mould developing.

Adjusting For Flour, Weather, And Storage

A starter does not have to be fed with the same flour forever. Wholemeal flour gives excellent early momentum, bread flour creates a milder culture, and rye often produces vigorous fermentation with a distinct earthy aroma. You can feed it with a blend, such as 25 grams rye and 25 grams white flour, then adjust the mix according to the flavour and activity you prefer.

Hydration changes the character of the culture. Equal weights of flour and water make a thick batter, known as 100 percent hydration. A stiffer starter ferments more slowly and may be easier to manage in a hot kitchen, while a looser one can show bubbles quickly but may rise and collapse before you notice. If your starter seems runny and sluggish, reduce the water slightly at the next feeding.

Australian weather calls for flexibility. In summer, a culture may need feeding twice a day, especially in Darwin, Cairns, or a warm pantry in Perth. In winter, it may need 24 to 36 hours between feeds. Use lukewarm water in cold weather and avoid placing the jar directly on a hot appliance. If you are heading out for the arvo, feed the starter before leaving and mark the level so you can see how far it has travelled.

For a starter that you bake with once or twice a week, refrigerate it after feeding. The cold slows fermentation and allows it to rest for several days. When you plan to bake, bring it to room temperature, discard most of it, and feed it once or twice until it rises strongly again. A starter kept in the fridge may need more than one refreshment after a long absence.

Baking With It And Keeping It Healthy

When a starter is active, use it close to its peak. This is generally when it has doubled, looks aerated, and has a gently domed surface. If it has collapsed, it is still usable, but the dough may ferment more slowly and taste more acidic. Reserve a small amount in the jar before taking starter for bread so the culture continues from a healthy base.

A basic loaf might use 100 grams active starter, 350 grams water, 500 grams bread flour, and 10 grams salt. Mix the flour and water first, rest for 30 minutes, then add the starter and salt. During the first few hours, fold the dough every 30–45 minutes to build strength. Let it rise until puffy rather than relying only on the clock, shape it, and refrigerate overnight before baking in a covered Dutch oven.

Your discard does not need to be wasted. Stir it into pikelets, crackers, waffles, pizza dough, or savoury fritters. Its tang works especially well with robust herbs and vegetables; a batch of discard crackers would be a natural partner for fresh herb chimichurri. In Australian homes, where a barbecue or shared plate is often part of the weekend, sourdough discard can add an appealing crisp, fermented note to snacks and flatbreads.

For seasonal serving ideas, sourdough can sit alongside vegetables as comfortably as it does with butter and jam. Toasted slices are excellent with soup, poached eggs, or a warm salad, and their nutty flavour suits roasted cauliflower with turmeric. Browse regional food traditions for further inspiration too, including the garden-to-table spirit found at Il Mondo di Ortolandia.

Habits That Keep A Starter Reliable

• Keep a small maintenance culture so daily feeding uses less flour and creates less discard.
• Mark the jar after feeding and record the time, flour blend, and room temperature when troubleshooting.
• Feed by weight rather than volume for consistent hydration and predictable fermentation.
• Refrigerate the starter when you are not baking regularly, then give it one or two room-temperature feeds before use.
• Use a clean jar and utensils, especially after scraping dried starter from the rim.

A little routine makes sourdough far less demanding. Feed it when you are already making breakfast, keep notes during the first week, and adjust the schedule to your kitchen rather than forcing the culture to follow an exact calendar. Once the starter becomes predictable, it turns from a science experiment into a dependable pantry staple: fragrant, active, and ready whenever the next loaf begins.