How to Make Your Own Sourdough Starter

The simplest definition of sourdough comes from the dictionary: leaven, especially fermented dough retained from one baking and used, rather than fresh yeast, to start the next. But sourdough is so much more than simply a way to make bread rise.

It's an enticing, tangy flavor; a snapshot of American culinary history, and a classic ingredient in everything from pancakes to pretzels. It's a part of the family for its aficionados—a living ingredient that thrives on flour and water and love.

And most of all, it's an endlessly fascinating subject for bakers of all stripes. From the beginner first picking up a bowl and spoon to the veteran who's kept a starter happy and lively for 30 years, sourdough reaches out and grabs our imagination, reminding us that the simplest beginning—flour and water—can lead to magic.

What is sourdough, anyway?

Sourdough refers both to bread, and to the starter used to make it. Sourdough starter begins with a combination of flour and liquid. The proportion and type of flour and liquid can vary dramatically, from a stiff starter made entirely with rye flour and water, to a liquid batter of milk and cornmeal, and everything in between.

Friendly bacteria (lactobacilli), present in our natural environment; and the wild yeast attracted to and living on flour begin to work with one another when flour is mixed with warm water. The result: sourdough starter. These tiny living creatures (lactobacilli and yeast, collectively called the sourdough's microflora) generate byproducts that cause bread to rise and give it complex, rich flavor.

But sourdough starter's not just for bread. Our early settlers used it to leaven pancakes and biscuits; today, we enjoy sourdough starter in treats as diverse as chocolate cake and pizza, where we value it for its rich, complex flavor as much as its ability to make things rise.

How does sourdough make things rise?

Wild yeast is a tiny fungus. It exists all around us in varying degrees—in the air, settled on work surfaces, and in some of the ingredients you bake with: most importantly, flour.

Lactobacilli are also all around us. They have a wonderfully symbiotic relationship with wild yeast; when the two are brought together with flour and water, the result is high-rising, delicious bread, or light, fluffy pancakes.

How does it all work to make dough rise? Lactobacilli (remember, they're all around us; you don't need to "add" them) break down flour's complex carbohydrates into simple sugars—exactly what yeast needs for food. The yeast, feeding on these simple sugars, produces carbon dioxide bubbles. The elastic wheat gluten in bread dough traps these carbon dioxide bubbles, causing the dough to expand as if it contained a million tiny balloons.

When you put a risen loaf into the oven, the yeast quickly dies; but the CO₂ it generated remains trapped beneath its flour/water matrix, producing a golden loaf of beautifully risen bread.

reference :

http://www.kingarthurflour.com/recipes/sourdough-starter-recipe

How to Make Your Own Sourdough Starter

What You Need

Ingredients
100 gr        Hard Flour
60 gr        Water

Equipmentglass or plastic container
Scale (highly recommended) or measuring cups
Mixing spoon
Plastic wrap or clean kitchen towel

Instructions

Making sourdough starter takes about 7 days. Each day you "feed" the starter with equal amounts of fresh flour and water. As the wild yeast grows stronger, the starter will become more frothy and sour-smelling. On average, this process takes about 7 days, but it can take longer depending on the conditions in your kitchen. As long as you see bubbles and sings of yeast activity, continue feeding it regularly.

Day 1: Make the Starter

Weigh the flour and water, and combine them in the container. Stir vigorously until combined into a smooth batter. It will look like a sticky, thick dough. Scrape down the sides and loosely cover the container with plastic wrap or the or with a clean kitchen towel secured with a rubber band 

Temperature :
Put the container somewhere with a consistent room temperature of 70°F to 75°F (like the top of the refrigerator) and let sit for 24 hours. 

Condition :
o   The color is bright and white
o   Texture is sticky
o   Smells like usual dough
 

Day 2: Feed the Starter   

4 ounces (3/4 cup + 2 tablespoons) all-purpose flour

4 ounces (1/2 cup) water 

Take down your starter and give it a look. You may see a few small bubbles here and there. This is good! The bubbles mean that wild yeast have started making themselves at home in your starter. They will eat the sugars in the the flour and release carbon dioxide (the bubbles) and alcohol. They will also increase the acidity of the mixture, which helps fend off any bad bacterias. At this point, the starter should smell fresh, mildly sweet, and yeasty.

If you don't see any bubbles yet, don't panic — depending on the conditions in your kitchen, the average room temperature, and other factors, your starter might just be slow to get going.

Weigh the flour and water for today, and combine them in the container. Stir vigorously until combined into a smooth batter. It will look like a sticky, thick dough. Scrape down the sides and loosely cover the container with plastic wrap or with a clean kitchen towel secured with a rubber band. Put the container somewhere with a consistent room temperature of 70°F to 75°F (like the top of the refrigerator) and let sit for 24 hours. 

Day 3: Feed the Starter

 

4 ounces (3/4 cup + 2 tablespoons) all-purpose flour
4 ounces (1/2 cup) water 

Check your starter. By now, the surface of your starter should look dotted with bubbles and your starter should look visibly larger in volume. If you stir the starter, it will still feel thick and batter-like, but you'll hear bubbles popping. It should also start smelling a little sour and musty.

Again, if your starter doesn't look quite like mine in the photo, don't worry. Give it a few more days. My starter happened to be particularly vigorous!

Weigh the flour and water for today, and combine them in the container. Stir vigorously until combined into a smooth batter. It will look like a sticky, thick dough. Scrape down the sides and loosely cover the container with plastic wrap or with a clean kitchen towel secured with a rubber band. Put the container somewhere with a consistent room temperature of 70°F to 75°F (like the top of the refrigerator) and let sit for 24 hours. 

Day 4: Feed the Starter

4 ounces (3/4 cup + 2 tablespoons) all-purpose flour
4 ounces (1/2 cup) water

Check your starter. By now, the starter should be looking very bubbly with large and small bubbles, and it will have doubled in volume. If you stir the starter, it will feel looser than yesterday and honeycombed with bubbles. It should also be smelling quite sour and pungent. You can taste a little too! It should taste sour and somewhat vinegary.

When I made my starter here, I didn't notice much visual change from Day 3 to Day 4, but could tell things had progress by the looseness of the starter and the sourness of the aroma.

Weigh the flour and water for today, and combine them in the container. Stir vigorously until combined into a smooth batter. It will look like a sticky, thick dough. Scrape down the sides and loosely cover the container with plastic wrap or with a clean kitchen towel secured with a rubber band. Put the container somewhere with a consistent room temperature of 70°F to 75°F (like the top of the refrigerator) and let sit for 24 hours. 

Day 5: Starter Is Ready to Use

Check your starter. It should have doubled in bulk since yesterday. By now, the starter should also be looking very bubbly — even frothy. If you stir the starter, it will feel looser than yesterday and be completely webbed with bubbles. It should also be smelling quite sour and pungent. You can taste a little too! It should taste even more sour and vinegary.

If everything is looking, smelling, and tasting good, you can consider your starter ripe and ready to use! If your starter is lagging behind a bit, continue on with the Day 5 and Beyond instructions. 

Day 5 and Beyond: Maintaining Your Starter

 

4 ounces (3/4 cup + 2 tablespoons) all-purpose flour
4 ounces (1/2 cup) water

Once your starter is ripe (or even if it's not quite ripe yet), you no longer need to bulk it up. To maintain the starter, discard (or use) about half of the starter and then "feed" it with new flour and water: weigh the flour and water, and combine them in the container with the starter. Stir vigorously until combined into a smooth batter.

If you're using the starter within the next few days, leave it out on the counter and continue discarding half and "feeding" it daily. If it will be longer before you use your starter, cover it tightly and place it in the fridge. Remember to take it out and feed it at least once a week — I also usually let the starter sit out overnight to give the yeast time to recuperate before putting it back in the fridge. 

How to Reduce the Amount of Starter

 

Maybe you don't need all the starter we've made here on an ongoing basis. That's fine! Discard half the starter as usual, but feed it with half the amount of flour and water. Continue until you have whatever amount of starter works for your baking habits. 

How to Take a Long Break from Your Starter

 

If you're taking a break from baking, but want to keep your starter, you can do two things:

1. Make a thick starter: Feed your starter double the amount of flour to make a thicker dough-like starter. This thicker batter will maintain the yeast better over long periods of inactivity in the fridge.
2. Dry the starter: Smear your starter on a Silpat and let it dry. Once completely dry, break it into flakes and store it in an airtight container. Dried sourdough can be stored for months. To re-start it, dissolve a 1/4 cup of the flakes in 4 ounces of water, and stir in 4 ounces of flour. Continue feeding the starter until it is active again.