Stories and Science of SOURDOUGH



You know the little organism responsible for making fluffy bread? I’ve always thought it only came in packets or in a little jar. Turns out yeast is all around us, in the air, on our kitchen
surfaces, and in our flour. To make sourdough, you’re simply giving naturally occurring yeast time and food to grow so it can raise your bread. Mix some water and flour, set it on your counter, wait for it to bubble, and feed it when it’s hungry. Soon enough, you’ll grow enough little yeast cells to leaven your bread! The tangy flavor of sourdough bread is a byproduct of bacteria also feasting on the flour. Strange, isn’t it? When you make a sourdough start, you’re growing your own little ecosystem of fungi and bacteria. It’s a concoction of living organisms that will reward you with yummy baked goods for generations if you take care of it regularly.

Sourdough Starter

Day 1. Combine whole wheat flour with water in a nonreactive container. Stir everything together so there’s no dry flour anywhere. Cover the container loosely (using a paper towel will allow microbes to enter and exit). Let it sit at room temperature (about 70 F) for 24 hours.

Day 2. Discard half the starter; add a scant 1 cup of unbleached all-purpose flour and 1/2 cup water. Mix well and let sit for 24 hours

Day 3. You’ll likely see some bubbling, smell a fresh fruity aroma, and see some expansion. It’s now time to begin two feedings daily, as evenly spaced as you can. Stir down the starter, remove a generous 1/2 cup, and place in a clean container; discard the rest. Add a scant 1 cup of flour and 1/2 cup of water and mix. Wait approximately 12 hours before repeating. Repeat these steps for days 4-5. If you’re not seeing much expansion and bubbles between feedings, just wait until you do. I was following directions to a “T” and nothing seemed to be happening. As I waited a little longer between feedings I started seeing more growth. Different variables might mean your starter grows faster or slower. Be patient!

How do you know if your starter is ready? One way to tell is to drop a small scoop of your starter into water. If it floats, it’s ready; if it sinks, your starter will need more time to develop. Another way to tell is if it’s doubling in size within 4-6 hours.

To keep your starter going– most people recommend feeding it once a week by discarding half the starter and mixing in 1 cup of unbleached all-purpose flour and 1/2 cup water. It’s a good idea if you refrigerate your starter to take it out after feeding it and let it sit at room temp before using for a recipe. Scientist Carl De Smedt said you can go up to 2 months between feeding before you start losing the fungi and bacteria. If you see a pink or orange tint or streak, this is a sure sign that your sourdough starter has gone bad and should be discarded.


Creating a starter means throwing away or discarding about half of it each time you feed it. It’s important to discard some to keep your starter a manageable size and to have less yeast and bacteria competing for food. I didn’t have the heart to throw it all away, so I saved it all in a separate container and used it to make waffles, pancakes, and crackers. I really liked these sourdough discard waffles from the recipe linked below:

The Stories behind the Sourdough

Gloria Gross is holding a sourdough starter that dates back to 1960!!

Gloria D. Gross has had the same sourdough start in their family for many years now. Their sourdough has been continuously fed and used since sometime around 1960. LaMar Hortt is Gloria’s father, and he deserves some of the credit for the start she has now, although he wasn’t the one who actually created it. His father, James Henry Hortt, had a start and used it when he was in Southern Utah. LaMar went with his Dad for periods of time to help him with his work. He longed for the biscuits his father made for their meals, but his father’s start was gone. LaMar began experimenting with water and flour around 1960, attempting to grow his own starter. He forgot that sourdough needs time to raise and that is what kept him from success.

His sister, Beth Hortt Murphy, saw his efforts and decided to give it a try. She created the one Gloria still uses to this day. Here is an excerpt from her family’s history on their sourdough, written by Lila Hortt: “The stories are legend of how the miners in that long ago era loved the good bread that sourdough gave them. The alternative was “hard tack”, which must have been just what its name implies. It is said that if a miner lost his start, he would trade a Bull Durham sack of gold for a start from a more provident miner. The story goes that they would sleep with their start in order to keep it active and ready to go in the cold, icy northern mornings.”

Wendy holding her start

I love the idea of recording your sourdough’s story. Some starts get passed on from one generation to the next, but it’s currently impossible to know the age of a start by testing it. It’s a living thing, and you’re constantly adding new water and flour to it, so the only way to know when and where a start originated is to record its history.

Wendy Ann Heinze, a resident in Roy, works in the bakery at Kent’s Market, and she got her sourdough from her mother-in-law. Her mother-in-law told her it came across the plains with the pioneers to Utah. Wendy uses it regularly to make sourdough pancakes, and we included the recipe she shared; see below!

Deena Goins Harris got her start from a friend in Nevada

Rodney Marchant is a resident in Syracuse, and his start is on its third year now; he really likes the flavor. “It just adds so much, instead of using bread as a vehicle to transport the rest of the sandwich, it adds flavor itself.”

Deena Goins Harris, a North Ogden resident, has been baking with sourdough for a shorter amount of time, and she got her start from her friend in Nevada. Her friend bought her start from King Arthur Flour, a company that sells flour and sourdough starts. If you have any questions about sourdough, Deena recommends going to their website I found it very helpful as well.

The Science of Sourdough

Each of these people were kind enough to share their starts with me. It seems I have my own little sourdough library in my fridge now!

Scientist Carl De Smedt cares for 128 sourdough starts from all over the world in his sourdough library in Berlin. One start dates back to 1874 and came from Tokyo. A woman in China got hers from her grandmother, who got it from her grandmother, and no one is sure how far back it goes. The strangest sourdough they have in the library comes from Japan, and it is made with cooked rice. They can keep the sourdoughs dormant for up to 2 months, but they risk losing the microbes that make them unique if they go longer than that between feeding them. They also have 2179 registered sourdoughs in their online collection at, and you can register your own there or explore around to see the different starts from all over the world.

Temps 77 degrees and below, favor the yeast which gives more fruity flavors. Higher temperatures favor the bacteria which results in a really sour sourdough.

You might wonder how a start doesn’t go bad. To leave food out on the counter for days with a plan to eat it later goes against what I’ve been taught. Flour provides sugar and starch, which is food for the bacteria and yeast that exist in the environment already. As the bacteria metabolize the flour, they produce acid, which keeps other microbes from growing. This same acid gives sourdough its sour flavor. The yeast in the starter produces CO2 and makes the bread rise and affects texture. It is also responsible for the aromas that contribute to the complex flavors and smells.

There are thousands of types of yeast in the world but only three types are produced commercially. Scientists Lauren Nichols and Erin McKenney explained that baking bread with traditional store-bought yeast is like living in a world where only brown, black, and yellow labs exist. In reality, there are SO many more types of dog breeds, and yeasts, than that. Not only are there the different types of domestic dogs, but there are also wolves, foxes, and hyenas. Sourdough harnesses the diversity of yeasts in the world!

A sourdough start can change in flavor over time, but the key to a consistent flavor is consistent conditions. Feeding it the same flour, using the same type of water, and storing it at the same temperature will help. However, it is next to impossible to keep a start one hundred percent the same over time. Microbes and yeast drift in and out of our homes; even having an open window can change the concoction of microbes! Scientist Karl De Smedt explained that it’s difficult to change the flora once it is established. He said the dominant species remains the same, but less dominant species will fluctuate.

Hailey’s first loaf of sourdough

After looking at starters from around the world, they found that the variations in the yeast were linked to the geographic location. Bacteria, however, doesn’t seem to follow the same geographical rules that yeast does. For bacteria, it seems like the diversity depends on the flour you use, the bacteria on your hands, and whether you keep it on your counter or in the fridge. They have also found the temperature you store your starter affects the taste. Lower temperatures, like 77 degrees and below, favor the yeast which gives more fruity flavors. Higher temperatures favor the bacteria which results in a really sour sourdough.

After gathering the different starts and thinking my own start was failing, I sat on my couch feeling sure I was going to ruin the starts I was entrusted with! “Is it too cold in my house? Am I not feeding it often enough? Am I feeding it too much and diluting the bacteria and yeast that are trying to grow? What if I fail at my starter? I certainly can’t be trusted to keep these other starters alive then! AHHH!!!” I baked a loaf with Deena’s start first and she digitally held my hand through the process over Facebook messenger. I’ve learned sourdough starts are pretty resilient, so if you’re wanting to venture into the world of sourdough, remember to keep trying, and failure, or perceived failure, is just another part of growing. My sourdough start eventually made a delicious loaf of bread and, wow, I felt like a winner when that loaf came out of the oven all puffy and golden!

Click the links below for some great Sourdough Recipes!

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