Build your first sourdough starter in seven days

Starting a sourdough starter from scratch relies on flour, water, time and temperature. The useful signal is repeatable rise: a healthy culture expands after feeding and often collapses before the next one. This method uses a small jar and a week of regular checks, so it suits busy Australian kitchens without specialist equipment.

Gather everything before mixing and keep a note of the temperature where the jar will sit. Australian recipes generally favour metric weights, so use a scale for grams rather than spoons; a few extra grams can change how a young culture develops. Choose a week when you can inspect the jar twice each day, because the schedule depends on those observations.

Choosing flour, water and a jar

Plain white wheat flour makes a light loaf, while wholemeal wheat flour gives the culture more activity and structure. Australian supermarkets stock both, and a 50:50 blend is a useful start: 50 grams wholemeal wheat flour and 50 grams plain flour, plus 100 grams water. Rye is optional, and strong white flour alone can make the earliest mixture sluggish.

You need a clear jar of about 250 millilitres, a rubber band, a teaspoon and a loose lid. Mark the starting level with the rubber band. Do not seal the jar airtight, because fermentation releases carbon dioxide and condensation can develop under a tight cover. Clean utensils are enough; boiling or chemical sterilising is unnecessary.

Use potable water at roughly 24–26°C for an even start. Sydney’s mains water is chlorinated, although supplies differ across Australia, so use drinking water and let it stand, covered, if it has a strong chlorine taste. A steady indoor spot suits a cool Melbourne kitchen, while Brisbane’s warm, humid weather calls for shade from direct sun.

Day one: Mixing and resting

Combine both flours with the water in the clean jar. Stir until the dry patches disappear; a smooth paste is not essential, since small lumps break down during the first day. Cover loosely, mark the time and leave at room temperature for 24 hours. This blend is also called a levain or preferment, although its wild yeasts and lactic acid bacteria are still establishing themselves.

After 24 hours, look for a faint tang, a slightly domed surface or bubbles around the edge. Some mixtures barely change on day one. Resist adding extra flour or water to force a dramatic rise; the aim is a stable culture rather than an impressive first day. Smell the jar and inspect through the glass rather than repeatedly tasting the mixture.

Move on to the first feed if the mixture smells fresh. Keep the jar indoors and away from a hot oven. Pink, orange or black patches, or mould on the surface, mean the whole batch should be discarded; clean the jar and begin again with fresh flour and water.

Days two and three: The first feeds

On day two, discard all but 50 grams of the mixture, then add 50 grams plain flour and 50 grams water. This 1:1:1 feed is measured by weight. Stir, cover loosely and mark the new level. Bubbles may appear within hours in a warm kitchen; a cool room may need the full day, so feed again after 24 hours if nothing has changed.

On day three, the mixture should smell more like sour milk or yoghurt and may have doubled. A domed top or bubbles along the sides are encouraging, even if the surface has already fallen. Feed with 50 grams starter, 100 grams flour and 100 grams water. If the mixture runs down the jar, use a little more wholemeal flour in the next feed for structure.

A watery film can be hooch, a byproduct of bacteria in the culture. If the starter still smells clean and rises, pour off the liquid and continue feeding; a strong chemical smell alongside a film calls for a clean restart. Repeated hooch means keeping the jar cooler and using smaller, more frequent feeds rather than adding more water.

Days four to seven: Building strength

On day four, give the bubbly culture a 1:2:2 feed: 50 grams starter, 100 grams flour and 100 grams water. The fresh food should produce a clearer rise within four to six hours at room temperature. Pleasant aroma but no expansion means the culture needs more time, not a larger jar.

On day five, repeat that feed and time the rise. Doubling with a domed top is more dependable than foam alone. Draw a rubber band around the bottom of the highest point for an easy comparison. If the rise takes eight to twelve hours in a cool room, leave the culture there and let it work more slowly.

For a readiness test on day six, mix one teaspoon of active starter with 20 grams flour and 20 grams water. Cover and leave at room temperature for four to six hours. It should smell tangy, show bubbles and rise about one centimetre. Some lively starters rise unevenly, so a slight fall is acceptable if the aroma remains pleasant and the bubbles persist.

By day seven, use 50 grams of active starter within several hours of its peak. Keep notes on temperature, feeding times and expansion if you want repeatable results. This guide to growing a hobby blog shows how documenting those details can become a modest side project once the routine is reliable.

Comparing flour choices and readiness

Flour affects both fermentation and the finished loaf. Wholemeal ferments faster because it contains more bran and germ; white flour can make a lighter crumb; rye ferments quickly and creates a dense, malty loaf. Hydration is water weight divided by flour weight, so equal weights mean 100 per cent hydration. Change one variable at a time rather than rebuilding the whole routine.

Readiness depends on several signals: increased volume, bubbles held in the dough, a pleasantly sharp smell and enough strength to stretch without tearing. Time alone is unreliable because a Melbourne winter and a humid Brisbane summer can produce very different schedules. Judge the culture by its behaviour, then adjust the next feed.

Independent bakers around Melbourne’s Queen Victoria Market or Adelaide’s Central Market can be useful local sources of advice, and their loaves show how flour behaves in familiar ovens. Supermarket bread labelled “sourdough” may include commercial yeast alongside a preferment, so it is not always long-fermented. Food Standards Code 1.2.3 requires wheat to be declared as an allergen, so check the ingredient panel rather than relying on the front label.

A sustainable routine for regular baking

Once the culture is reliable, feed 50 grams of it with 100 grams flour and 100 grams water, then discard the remainder. Feed before baking instead of maintaining a large jar daily. In cool weather, refrigerate the starter and feed every second or third day; if it seems dry, add a teaspoon of water before closing the jar. Related low-waste ideas are part of the everyday approach at New Urban Habitat.

A few habits make the process economical and keep results easy to read:

• Weigh every ingredient and note the room temperature and time taken to double.
• Keep a backup jar in the refrigerator so one poor batch does not undo a week’s work.
• Use discard for pancakes or crackers, and bake some for croutons.
• Buy flour in quantities you will use within a few months and refresh the supply before a feeding cycle.

For a first loaf, mix 500 grams bread flour with 350 grams water and rest for 45 minutes. Add 10 grams salt and 50 grams active starter, knead until smooth and complete three sets of folds at 15-minute intervals. Let the dough rise by about 50 per cent, shape it into a boule and refrigerate seam-side up in a floured bowl for 8 to 12 hours. Bake at 230°C for 20 minutes in a covered casserole, then 220°C for 20 minutes uncovered. An oven thermometer helps because Australian ovens vary; a fan setting generally needs a lower temperature than a conventional setting.

Your first loaf may be dense, over-proofed or pleasantly rustic, and each bake clarifies the starter’s timing and the oven’s heat. Keep the successful schedule and adjust one variable at a time. The next concrete step is 50 grams of flour and 50 grams of water in a clean jar tonight, with checks scheduled for tomorrow morning and evening.