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Back to Basics: Sourdough

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Earlier this week we talked about yeast: what it is, how it works, and the differences between types of yeast. Today we are going to continue that lesson by learning about sourdough.

Side view of bubbly sourdough starter in a glass jar in front of a marble backsplash

Sourdough is a special type of dough that differs from other yeast dough in that it contains naturally occurring yeasts (as opposed to the cultivated yeasts that we discussed earlier) in combination with a Lactobacillus culture and requires a long fermentation process.

Wait a second. We already learned that yeast is a fungus…and now we are adding bacteria to the mix? You bet!

But before you get too grossed out, remember that Lactobacillus cultures are used in the production of all kinds of other foods, including yogurt, cheese, pickles, beer, and wine, just to name a few. It is the lactic acid produced by the Lactobacilli that gives sourdough its distinctly sour taste.

In order to make sourdough bread, you must begin with a sourdough starter.

There are many types of starters, but the most basic ones are made of flour and water. The starter allows the yeast and bacteria to grow and develop, which ultimately develops the flavor of the bread and allows the dough to rise.

Because the starter is, in fact, alive, it must be taken care of and “fed” regularly with additions of flour and water. In this way, sourdough starters can be kept alive for years – there are even stories of sourdough starters being passed down from generation to generation.

Now, all of this may sound like a lot of work. Having to keep something alive and tend to it?

You might be thinking that this just isn’t for you. I once felt the same way! But really, starting and tending to a sourdough starter is not as difficult as it may seem.

To start, get a 2-quart glass jar or other container. Using the recipe below, combine your starchy potato water, flours and a bit of yeast in the jar, stirring vigorously to combine.

While natural yeasts will eventually develop, we are adding a bit of cultivated yeast to our starter just to give it a little kick-start.

Cover the jar with cheesecloth and set it in a warm place.

That is it! Once a day, give it a good stir. Smell it. Is it starting to smell slightly sour and fermented? (Read: Is it starting to smell a little like beer?) You’re on the right track!

Overhead view of bubbly sourdough starter in a glass jar on a marble counter

In about 4-10 days it will start to smell nice and sour. Once it reaches this point, pour out half of the starter. You may use or throw away this starter – although, if you choose to use it, it will not have developed a very distinct sourdough flavor yet, as that takes time to develop and will get stronger with age.

Pour the other half of the starter into a clean jar and add 1 cup of white flour and just shy of 1 cup of water – you want your starter to be about the consistency of pancake batter. Cover it again with the cheesecloth and allow the starter to sit in a warm place overnight.

In the morning, place it in the refrigerator.

At least once a week, repeat the feeding process: use, discard or give away half of the starter, and add 1 cup of flour and less than 1 cup of water to the other half, leave it out overnight and return it to the fridge the next morning.

When you go to feed your starter, you may notice that a liquid has gathered at the top, ranging in color from light yellow to dark brown. This is just the alcohol produced by the yeast; simply stir this into the starter before dividing it.

However, if you notice any mold growing on the top of your starter, it means that your starter has died and you need to start over – or snag some starter from someone else. This actually happened to me once and I had to snag some of my mother’s starter.

The best way to prevent this from happening is to be diligent about feeding your starter regularly, and try not to go longer than a week between feedings.

So, what can we do with our sourdough starter? Well, for starters (see what I did there?), we can make an easy sourdough bread – and that’s exactly where we will begin on Friday! Other options include pancakes, waffles, dinner rolls, sourdough banana bread…the possibilities really are endless, and will all be explored here in due time.

So for now, get yourself a jar and get growin’!

Sourdough starter adapted very slightly from How to Bake a Perfect Life.

Easy Sourdough Starter

Overhead view of bubbly sourdough starter in a glass jar on a marble counter
Prep Time 5 minutes
Inactive Time 10 days
Total Time 10 days 5 minutes


  • 2 cups potato water
  • 1/2 cup rye flour
  • 1/2 cup whole wheat flour
  • 1 cup unbleached all-purpose flour
  • 2 teaspoons active dry yeast


  1. In a 2-quart jar, mix all of the ingredients until smooth. Cover loosely with cheesecloth and let stand in a warm spot. Stir every 24 hours, until bubbly and agreeably sour, usually 4-10 days.
  2. When it is ready, store loosely covered in the fridge.
  3. Once a week, feed your starter: Remove from the fridge and stir vigorously, then divide starter in half. Either use, throw away or give away one half. Pour the other half into a clean 2-quart jar; add 1 cup of unbleached white flour and just enough water to make consistency similar to pancake batter (usually 1/2 to 3/4 of a cup). Re-cover with the cheesecloth and allow to sit in a warm place overnight, placing back in the fridge the next morning.


To make potato water, boil potatoes in water until tender. Drain, reserving the water for your starter. Use the cooked potatoes as you wish!

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Rustic Sourdough Bread

Lizanne Jordaan

Saturday 21st of March 2020

Hi there from South Africa. Just a quick question. Do I have to use rye flour as I don't have any. Can I just use regular wheat cake flour?


Saturday 16th of May 2020

Hi Lizanne - I haven't tried this particular starter without rye, but I have done other starters with just all-purpose flour. Seems worth a try!


Wednesday 11th of March 2015

My starter's name is Herman. He is my pet and so we call him "my pet Herman." Always have. :) Love that I'm not the only one that named her starter!


Wednesday 18th of March 2015

Love that!!

KC the Kitchen Chopper

Monday 27th of October 2014

I'm always so curious as to what you'll bring to #theWeekendSocial table. I can almost smell the sourdough baking from here. Thanks for this Starter recipe. Pinned. Can't wait to see you're up to this week. Pinned!

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