Starting a Sourdough Starter

Getting a sourdough starter is easy. Anyone can do it as long as you observe some simple directions. Flour wants to ferment; you just need to get out of the way and let it happen.

There are many different ideas out there about how to get sourdough started, and numerous different techniques for maintaining a starter, many of which are baked into the cultural history of a particular region. My instructions are based off my experimentation using several different techniques. This guide produces a 100% hydration starter, meaning equal parts water and flour. You can experiment with different hydration levels. My preference is actually 80% hydration, but most recipes are written assuming your starter is at 100%, so for simplicity’s sake we’ll use that as our starting point.

The first thing you’ll need is flour. There are different ideas about this as well, but I recommend starting with 100% whole grain flour. The natural yeasts that ferment a sourdough starter live primarily on the wheat bran. White flour has had the bran removed. Although you can start a sourdough starter with white flour, you will have better odds starting with whole wheat. You can always transition your starter to using white flour (either all purpose or bread flour) later if you don’t want to use whole wheat for baking. If you prefer, you can also start with half whole wheat and half white flour.

The second thing you’re going to need is a clear container for your starter to live in. I like to use a pint-size Mason jar. It’s important to pick a container that is larger than you think you’ll need, because your starter will grow. Your sourdough starter needs to be covered but not sealed. I found I can use an inverted soufflé ramekin on top of my mason jar to keep it closed and safe from the elements. Basically you need to be able to keep dust and mold spores from getting into it, while allowing CO₂ to easily escape (hence why you don’t want it sealed).

The third thing you need is a scale capable of measuring in grams. You’re going to need this for baking anyway, so pick one up if you don’t have one.

Lastly, it’s really handy to have some chopsticks as well. They are really useful for mixing up starter. If you don’t have any chopsticks, no biggie, you can also use a butter knife.

Instructions

Day 1

1. Before starting, make sure everything is immaculately clean with no soap residue: your hands, the jar/container, your work surface, your utensils, etc. Sourdough is most vulnerable to mold issues in the first week or so, so we want to eliminate any extra sources of bacteria and mold spores.
2. Using your scale, weigh the jar or container your sourdough is going to live in. Take note of the weight in grams somewhere handy because you’ll be referring back to it regularly.
3. Add 50 grams of whole wheat flour to the jar.
4. Add 50 grams of lukewarm (about 72°F) water to the jar.
5. Stir it vigorously with your chopstick or butter knife until it forms a paste.
6. Cover it with plastic wrap or some other loose covering.
7. Place it in a warmish, non-drafty spot, such as on top of your fridge.

That’s it! Your sourdough starter has been born! Write down the date and give it a name. Tradition dictates that you pick a French name, but it can be whatever name you want. From here, it’s important to examine your starter periodically. Look at it for signs of activity. Smell it too—your nose will tell you when things are going the right way.

Over the following 24-72 hours you will probably see quite a lot of activity from your starter. Bubbles and gas will form, causing the starter to double or even triple in size. The smell will go from a wet cereal smell to something more complex (and sometimes kind of funky, especially at first). Competing bacteria and yeasts will fight over the starches in the flour, causing a lot of bubbling. You may also see hooch (alcohol) production, which will look like water on top of the starter. All of this is totally normal and good. What we are waiting for at this point is for the starter to become acidic. The lactobacillus bacteria naturally present in the flour will produce lactic acid, causing the pH of the starter to drop. As this happens, it creates an environment that is especially conducive to the yeasts and bacteria that we want in the starter. As the starter becomes acidic, this also makes it more resistant to mold and bad bacteria that we don’t want growing in the starter.

If, after 72 hours, you don’t observe any activity, give it another couple of days. Sometimes it takes up to a week to really show signs of activity, especially if you are starting it in the winter. As long as it doesn’t become moldy, it should be fine.

Feeding Your Starter (Day 5-7+)

At some point you will need to start to feed your starter. When the first feeding takes place depends on the activity level of the starter, but usually I wait until activity seems to have slowed down a bit and the smell is faintly (or strongly) yeasty. Typically, in my experience starting sourdough in summer, this is usually between day 5-7 or so. There’s no great harm in feeding it early, so don’t stress about the timing too much.

1. Stir down the starter using your chopstick or butter knife. Give it a whiff. It should smell pretty good at this point, but if it still smells a bit funky or like old cheese, don’t worry.
2. Discard all but 20 grams of the starter. The easiest way to do this is to use your scale. Find the weight of the jar that you wrote down on day one and add 20 grams to that. Discard until you reach the target weight. Note that 20 grams isn’t much. You’ll probably end up with about a teaspoon of starter in the bottom of the jar and a bunch stuck to the walls. That’s fine; you really don’t need much.
3. Add 40 grams of lukewarm (about 72°F) water to the jar. Using your chopstick, vigorously mix the starter and scrape down the sides a bit to dissolve as much of the starter as possible in the water.
4. Add 40 grams of whole wheat flour to the jar and stir vigorously with your chopstick until it forms a paste.
5. Cover and place back in its spot.

You can save your discarded starter eventually by throwing it in a container in the fridge, using it in pancakes or other recipes like that, but for the first feeding, just toss it.

As long as your sourdough starter is kept at room temperature, you need to feed it daily from here on out. I like to feed it in the morning so I can observe it throughout the day to really know when it’s ready to bake with.

How Do I Know when It’s Ready to Use?

Your sourdough starter will be ready to use when it can reliably double within 6-8 hours after each feeding. There should be a nice, pleasant smell to it as well, somewhat yeasty, reminiscent of beer, with some cereal undertones. How long this will take really depends. Some starters are ready for baking within a week or so, sometimes it takes two weeks. Again, a lot of it depends on the time of year you start your starter and the corresponding ambient temperature of your house.