A sourdough starter is nothing more than flour and water that has been given time to gather wild yeast and friendly bacteria. It sounds mysterious, but it is one of the simplest and most rewarding things you can make in your kitchen. With a little patience, you can have a lively starter in about a week, ready to raise bread for years to come.
What You Need
You do not need any special equipment. Gather a clean glass jar, a kitchen scale, a spoon or spatula, a rubber band and a loose lid or cloth. For ingredients, you only need whole wheat or rye flour, plain white flour and water.
Choosing Your Flour
Whole grain flours contain more natural yeast and nutrients, which is why we recommend starting with whole wheat or rye. After the first few days you can switch to plain white flour for feedings. Unbleached, stone-ground flour tends to give the fastest, most reliable results.
Choosing Your Water
If your tap water is heavily chlorinated, let it sit out for an hour or use filtered water. Lukewarm water, around 25 degrees Celsius, helps get things moving.
Day-by-Day Instructions
Day 1: Mix
In your jar, stir together 50 grams of whole wheat or rye flour and 50 grams of lukewarm water until no dry flour remains. Cover loosely and leave it at room temperature, ideally between 22 and 26 degrees Celsius, for 24 hours.
Day 2: Rest
You may see a few small bubbles, or nothing at all. Both are normal. Give the mixture a good stir, cover it again and wait another day.
Days 3 to 5: Start Feeding
Now begin the daily feeding routine. Discard all but 50 grams of the starter, then add 50 grams of white flour and 50 grams of water. Stir well, scrape down the sides and mark the level with a rubber band so you can see how much it rises. Around day three or four, the starter may smell sharp or even unpleasant for a short time. This is a normal phase and it will pass.
Days 6 and 7: Build Strength
By now the starter should be doubling in size within four to eight hours of feeding, with plenty of bubbles and a pleasant, tangy, slightly fruity smell. If it is not there yet, keep feeding daily. Some starters need ten days or two weeks, especially in cooler kitchens.
How to Know It Is Ready
A healthy starter reliably doubles after feeding, is full of bubbles throughout, and smells fresh and tangy rather than sour or harsh. A simple test is to drop a spoonful into a glass of water. If it floats, it is full of gas and ready to bake with.
Troubleshooting Common Problems
A Layer of Liquid on Top
This grey or brownish liquid is called hooch, and it simply means your starter is hungry. Pour it off or stir it in, then feed more often or use a little more flour.
No Activity
Move the jar somewhere warmer, switch to whole grain flour for a few feedings, and be patient. Cold is the most common reason for a slow starter.
Mould
Fuzzy spots in pink, orange or green mean the batch should be thrown away. Start again with a freshly sterilised jar.
Keeping Your Starter Healthy
If you bake often, keep your starter on the counter and feed it daily. If you bake once a week, store it in the fridge and feed it weekly, then give it one or two feedings at room temperature before you bake. Always use up your discard in pancakes, crackers or flatbreads so nothing goes to waste.
Once your starter is bubbly and reliable, you are ready to make your first loaf. Treat it well, and it will reward you with years of beautiful bread.
