How does sourdough starter work and how to make your own from scratch in just a week. Learn how to create and maintain a strong, active starter.

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In this blog I want to teach you how you to make your own sourdough starter, and how to maintain it. I’ve seen so much hype built around starters that are as old as time, and while I appreciate the tradition or the legacy of it kept going, an ancient starter is not necessary for successful sourdough baking. I made my own starter over a year ago and it has resulted in beautiful things. It takes about a week to create an active starter, but it can take up to two weeks for your starter to be strong enough to use in bread.

All you need to make your own starter is:

1. Water: You can't just use straight tap water. You need water that's filtered or purified. Tap water contains chemicals and impurities that can harm the starter's natural yeasts and bacteria. Most bottled waters are ok to use, and any water that's run through a purifier or like an RO system.
2. Flour: As long as it's unbleached flour, any kind of flour will work to feed your sourdough starter. My go-to is unbleached, all-purpose white flour. 
3. Glass jar: You can use plastic too, but metal disrupts the bacteria and yeasts. Glass is a good choice because it doesn't absorb flavors or aromas, doesn't leach into the starter, and is dishwasher safe. Plus using a wide mouth jar is super handy for feeding and stirrring without making a big mess, and because it's clear you can see the strength of the starter by looking at the bubbles. 

Which flour and water to use:

There are so many opinions on which flour and water to use. I used unbleached all-purpose flour. Bleached flour has chemicals that will hinder the wild yeast from developing. You can also use whole wheat flour. Same with water, for best results, you can’t just use tap water. The chlorine and the possibility of chemicals will hinder the strength of your yeast. It is possible to get a rise when using tap water because I have done it, but the results were so inconsistent. I had many flops until I started using only filtered RO water. This is the RO system we have, and I highly recommend this one because it has the remineralizer. I also love that it goes under the sink and doesn’t need counter space. Alternatively, you can use bottled water. 

Day 1~

Mix ½ cup unbleached flour and ¼ cup filtered water together in a glass jar. Cover it with plastic wrap or a lid but don’t tighten it. Let it sit in a warm place for 24 hours, such as the kitchen counter. 

Day 2~

It’s possible you won’t see any bubbles yet on Day 2. Don’t feed it on day 2. It probably has bubbles already but they might still be hiding. The mixture has caught wild yeast and microbial communities- which are everywhere- and are working together in harmony to create a living organism. I think it makes more sense not to disrupt that on the first day and just let the wild yeast multiply.

Day 3~

Today we’ll “feed” the starter. Remember it’s alive and needs to be fed in order to grow in volume and strength. Remove half of the starter from the jar, and add the same amount of flour and water as on the first day. The mixture will be stretchy and you won’t see many bubbles, if any at all.

Day 4~

Repeat the feeding process from day 3.

"Do I really have to dispose half of the starter? Can't I use it somehow?"

hated the part where you waste the sourdough starter discard every time you feed it, but at this point it’s not strong enough yet to do anything with. The more in volume it gets, the more you have to feed it so it’s best to keep the amount small. When your starter is established you can use the sourdough discard in recipes like these sourdough donuts or pancakes. I have come to a point where I have very minimal waste, I keep my starter in the fridge when I’m not using it so I don’t have to keep feeding it.

The "hooch"

Today or tomorrow you might see what’s called “hooch” appear in the middle or on top of your starter. There’s nothing wrong if it doesn’t show up but I’ve noticed it is common. If it appears at any point, just know that it’s normal and it means that your starter needs to be fed. Some people stir the hooch into their starter, it won’t hurt if you do but it does make the starter more sour if that’s something you like. I discard it when I see it.

Day 5~

You will see your sourdough starter rise, and fall at some point. When it falls, repeat day 3. Discard half and feed it ½ cup unbleached flour and ¼ cup filtered water.

Tip: put a rubber band around your jar after you feed it to measure how high it rises.

Day 6~

You should see plenty of bubbles by now, if you don’t, just give it another day or two before giving up. Repeat what you did in the previous steps but do it twice a day, 9-12 hours apart. Environmental conditions affect rise time, and those are different in different places but they also change with the seasons. Warm temperatures will facilitate a faster rise time, while cold temperatures will make your starter slower. 

Day 7~

Repeat day 6.

My starter was nice and bubbly by day 7 but since it's a new starter, it was not strong enough to bake with. You know if you have a mature starter by how bubbly it is and if it doubles in size after feeding. It should have a pleasant but sour smell. You can test it via the float test by drpping a spoonful in room temperature water and if it floats then it’s ready.

At this point you can either bake with it if it passes the test, or keep repeating days 6 & 7 until it's ready.

How to maintain your sourdough starter:

What do I do with my starter now? What if I only want to bake every few weeks or just once a week? How much do I feed it each time?

Store your starter in the fridge if you're not planning on baking with it.

The good news is it’s really hard to kill an established starter. Yes it can look dead and hooch-y, but its most always revivable. When it looks that way though, it might take an extra day or 2 of feeding to regain its strength and be ready to bake again. I have found my starter to be resilient even if I forget about it in the fridge for over a month. I do recommend feeding it every two weeks even if storing it in the fridge.

If you’re planning on doing some baking right away, depending on your recipe, you need to build it up to the amount your recipe asks for. Instead of discarding, just feed it a ratio of water/flour depending on the amount of starter you have. I guestimate how much starter I have, keeping in mind the bubbles and that they don’t count for volume. Stir it to deflate if you having a hard time guessing.

If I have for example, 1 cup starter, I’ll add 1 cup flour and ½ cup water. This is known as 100% hydration starter, which means it has equal amounts of everything BY WEIGHT. A cup of flour is close in weight to ½ cup water. This doesn’t have to be 100% exact, I just eyeball it and it’s worked perfectly fine. If it’s too runny I’ll add a bit more flour and if it’s too thick I’ll add more water. I prefer it on the thicker side, like a thick pancake batter.

Cover your jar with a cheesecloth tightened with a rubber band, or with saran wrap, or a lid just don’t close it off completely. It needs oxygen. Make sure there are no gaps for fruit flies to get in.

It will rise to its’ peak anywhere between 2-12 hours. The best time to use it is when it is at its peak, and you can see lots of bubbles at its surface.

I go more into depth on the hows and whys of sourdough in this post:

“Why Sourdough?” if you want to go deeper in the sourdough world, but honestly you can bake a lot of amazing things without knowing much of the science behind it;). I did it for a long time.

Tips

• Warm Location: Keep your starter in a warm, draft-free area. Ideal temperature range is between 70-75°F (21-24°C). Higher temperatures can speed up the process, while lower temperatures can slow it down.
• Time: It can take up to two weeks for your starter to become strong enough for baking. Patience is key during this initial phase.
• Activity Signs: Look for bubbles, a pleasant sour smell, and noticeable rise and fall after feedings as indicators of an active starter.
• Consistency: The starter should have a thick, pancake-batter-like consistency. Adjust the water or flour slightly if it’s too thin or thick.
• Smell and Appearance: If your starter develops a pink or orange tint or smells off, discard it and start over. A healthy starter should have a tangy, slightly sour smell.
• Mold: If you see mold, discard the starter and start fresh. Mold indicates contamination.
• Once Active: Once your starter is active and bubbly, you can reduce feedings to once every 12 hours if you’re baking frequently, or store it in the refrigerator and feed it weekly if you’re baking less often.
• Refrigerated Starter: If stored in the refrigerator, bring the starter to room temperature and feed it a few times (every 12 hours) to revive it before baking.
• Use a Kitchen Scale: Measuring ingredients by weight ensures consistent and accurate feeding ratios.

FAQs

1. What is a sourdough starter?

• A sourdough starter is a mixture of flour and water that has been colonized by wild yeast and lactic acid bacteria. It serves as a natural leavening agent for baking bread, providing both rise and flavor.

2. How does sourdough starter work?

• Sourdough starter works by harnessing wild yeast and bacteria from the environment and the flour. These microorganisms ferment the sugars in the flour, producing carbon dioxide gas, which makes the dough rise, and lactic acid, which gives the bread its tangy flavor.

3. How do I start a sourdough starter?

• Combine equal parts flour and water in a clean container. Stir well, cover loosely, and let sit at room temperature. Feed it daily with equal partsfresh flour and water, discarding a portion of the old starter before each feeding.

4. How long does it take to make a sourdough starter?

• It typically takes about a week to create an active starter, though it can take up to two weeks for the starter to become strong enough to use in bread baking.

5. What kind of flour should I use?

• Unbleached all-purpose flour works well, but you can also use whole grain flours like whole wheat or rye for a more robust starter. Whole grain flours tend to have more wild yeast and bacteria.

6. How often should I feed my starter?

• Feed your starter once every 24 hours during the initial creation phase. Once it’s active, you can feed it every 12 hours if you’re baking frequently, or store it in the refrigerator and feed it weekly if baking less often.

7. What is the best temperature for my starter?

• Keep your starter in a warm, draft-free area with a temperature range of 70-75°F (21-24°C) for optimal activity.

8. How do I know if my starter is ready to use?

• Your starter is ready when it’s bubbly, active, and has doubled in size within 4-6 hours of feeding. It should also pass the float test (a small amount of starter should float in water).

9. Why does my starter smell bad?

• A healthy starter should have a tangy, slightly sour smell. If it smells like nail polish remover or has an off, unpleasant odor, it may be due to insufficient feedings. Increase feeding frequency and discard more of the old starter.

10. Can I speed up the starter development process?

• You can try placing the starter in a slightly warmer environment (around 80°F or 27°C) to encourage faster yeast and bacterial growth. However, avoid temperatures above 85°F (29°C) to prevent killing the yeast.

11. What if I see mold on my starter?

• If you see mold or a pink or orange tint, discard the starter and start over. Mold indicates contamination and can be harmful.

12. How should I store my starter when not in use?

• Store your starter in the refrigerator in a loosely covered container. Feed it once a week to keep it healthy. Before baking, bring it to room temperature and feed it a few times to revive its activity.

13. Can I use my starter for other baked goods?

• Yes, a sourdough starter can be used in a variety of baked goods such as pancakes, waffles, muffins, and even pizza dough.

14. Why do I need to discard some starter during feedings?

• Discarding some of the starter helps manage its growth and maintains a healthy balance of yeast and bacteria. It also prevents the starter from becoming too large and unmanageable.

Storage

Short-Term Storage (Room Temperature)

Daily Feeding:

• Frequency: Feed your starter once every 24 hours.
• Amount: Use equal parts starter, flour, and water by weight.
• Environment: Keep it in a warm, draft-free spot around 70-75°F (21-24°C).

Long-Term Storage (Refrigerator)

Weekly Feeding:

• Frequency: Feed your starter once a week.
• Preparation: Before refrigeration, feed your starter and let it sit at room temperature for a few hours to become active.
• Storage: Place the starter in a clean, loosely covered container in the refrigerator.
• Revival: Before baking, bring the starter to room temperature and feed it a couple of times (every 12 hours) to reactivate it.

Freezing

For Extended Storage:

• Feeding: Feed your starter and let it become active.
• Preparation: Spread a thin layer of the starter on a piece of parchment paper and let it air-dry completely.
• Storage: Break the dried starter into pieces and store them in an airtight container or zip-lock bag in the freezer.
• Revival: To reactivate, crumble a piece of dried starter into water, let it dissolve, then feed it with flour and water. Repeat feedings until it's active and bubbly.

Freeze-Drying

For Very Long-Term Storage:

• Preparation: Use a freeze-dryer to thoroughly dry your starter.
• Storage: Store the freeze-dried starter in an airtight container, vacuum-sealed bag, or jar with a desiccant packet.
• Revival: Rehydrate the freeze-dried starter in water and start feeding it with flour and water until it becomes active and bubbly.

Tips for All Storage Methods

• Cleanliness: Always use clean utensils and containers to prevent contamination.
• Labeling: Label your containers with the date of storage and the type of flour used.
• Feeding Ratio:Stick to a 1:1:1 feeding ratio (starter:flour by weight) for consistency

Try one of these incredible sourdough recipes and let me know what you think!

• Sourdough Pumpkin Cinnamon Rolls
• Sourdough Baked Pumpkin Donuts