Creating a sourdough starter from store-bought yeast and flour is a bit different from the traditional method of using wild yeast. The sourdough flavor primarily comes from wild yeast and lactobacilli bacteria present in the environment, so using commercial yeast won't give you the same depth of flavor. However, if you want to try making a "faux" sourdough starter, here's how you can do it:
Ingredients:
- All-purpose flour or whole wheat flour (unbleached is preferable)
- Store-bought active dry yeast
- Lukewarm water (chlorine-free, as chlorine can interfere with yeast activity)
- A glass or plastic container (avoid metal containers, as they can react with the acidic environment of the starter)
Day 1:
Start by mixing 1/2 cup of flour (either all-purpose or whole wheat) with 1/3 cup of lukewarm water until you get a thick but smooth consistency. This is your initial mixture.
Add 1/4 teaspoon of store-bought active dry yeast to the mixture. The yeast will act as the initial leavening agent for the starter.
Transfer the mixture to the container, loosely cover it with a lid, cloth, or plastic wrap, and leave it at room temperature (ideally around 70-75°F or 21-24°C) for 24 hours.
Day 2:
Check your starter to see if there are any signs of activity. It might have risen a bit, and you may notice some bubbles forming.
Discard half of the starter (approximately 1/2 cup), and add 1/2 cup of flour and 1/3 cup of lukewarm water to the remaining starter. Mix well until smooth.
Cover the container again and let it sit at room temperature for another 24 hours.
Day 3 and onward:
Continue with the same "discard and feed" process once a day, roughly at the same time. By the third or fourth day, your starter should start showing more signs of life, with increased bubbling and a pleasant sour aroma.
On days when your starter seems weak or sluggish, you can feed it twice a day to strengthen it.
Note: Keep in mind that this method may not produce a true sourdough starter, as the wild yeast and bacteria that develop naturally in traditional starters contribute significantly to the sourdough flavor. However, this faux starter should give you a yeasted bread with some mild sourdough characteristics.
After a week or so, you should have a fairly active starter. At this point, you can experiment with using it in various sourdough recipes, though it may not have the same depth of flavor and complexity as a fully developed traditional sourdough starter. If you're looking for a more authentic sourdough experience, consider starting a new sourdough starter from scratch using just flour and water, and allowing it to capture wild yeast from the environment.