Gluten-Free Sourdough Starter

Gluten-free sourdough starter might not be the most common, but it’s no less easy to make at home than classic wheat or rye sourdough starter. In this guide you will learn how to create and maintain a healthy gluten-free sourdough starter, step-by-step, so you can start enjoying delicious, homemade sourdough bread in about a week!

Most cultures around the world rely on the actions of microbes to ferment food. Think about miso from Japan, kimchi from Korea, sauerkraut from across Europe, kombucha from China/Russia, or sourdough from ancient Egypt. Although fermented foods were initially produced as a means of preservation, it became quickly apparent that these foods possessed other desirable attributes. Compared to the raw ingredients from which they are made, fermented foods have unique flavors, textures, appearances, and nutritional value. 

Fermentation is a natural preservation process but one that few people do on their own anymore. Most people purchase pasteurized vegetables in supermarkets instead of fermenting their own. Yeast-risen breads are far more common than breads leavened with a sourdough starter. Canned carbonated tea is undeniably more convenient than brewing kombucha at home. I get it.

However, fermenting foods at home provides an opportunity to combine science with art to craft something nourishing and wholesome. An opportunity to embrace slower, more mindful cooking processes. And what better place to start than with the food the unites the majority of the world’s civilizations: bread.

Sourdough Starter

All yeast-leavened breads rely on the actions of microbes. The yeast used to make bread can be either cultivated from the environment around us in the form of a levain (sourdough starter) or commercially-manufactured (baker’s yeast).

The main difference between the two is yeast cultures. Sourdough starter is made up of many different “wild” yeasts and lactic acid bacteria, whereas baker’s yeast is is made up of only one yeast species. This is why each levain has a unique flavor and texture. No two sourdough breads are alike. 

A fun fact – the properties of a sourdough starter are actually based on local strains of yeast and bacteria. This variability in yeast influences the flavor and leavening time, which is why every region of the world produces a different type of sourdough bread. 

What is Sourdough Starter

Sourdough starter is essentially a medium for cultivating a symbiotic community of wild yeast and lactic acid bacteria. Wild fermentation depends on microorganisms that are naturally present around us whether it’s in raw food, in the jar where the sourdough is fermenting, or in the air. Since both wild yeast and bacteria are present on grains, an easy way to “capture” them is to combine flour and water, and let the mixture ferment for a few days.

When flour and water mix, enzymes (amylases) in flour convert long starch molecules into simple sugars. Both yeast and lactic acid bacteria feed on the simple sugars – yeast prefers to feed on glucose and fructose while lactic acid bacteria likes maltose. After a day or two, bubbles start to form in the starter, indicating that the microbes are starting to become active and multiply. The wild yeast begins to release CO2, which creates the rise and texture in sourdough bread. The lactic bacteria release lactic acid and acetic acid to create the sour flavor that sourdough is known for. And the enzymes unlock minerals otherwise unavailable to us. In other words, the complex, symbiotic ecosystem of a sourdough starter – a combination of wild yeast, bacteria and enzymes – works to leaven, flavor and build the structure of the dough. 

In about a week, the sourdough starter becomes a reliable “natural yeast” culture that can be used to leaven breads.

Gluten-Free Sourdough Starter

The majority of sourdough starters is not gluten-free. While fermentation makes sourdough bread more gut-friendly, it does not make it gluten-free.

The wild yeast and bacteria in a sourdough starter break down some of the carbohydrates and proteins found in flour, including gluten. However, the amount of gluten does not reach 20ppm (parts per million) or less of gluten, which is how the United States defines gluten-free foods. The only way to make gluten-free sourdough bread is to use gluten-free sourdough starter made with gluten-free ingredients.

Liquid Starter vs Stiff Starter

There are two types of sourdough starter – liquid and stiff. The difference lies in hydration, that is the amount of water compared to the amount of flour.

1. Liquid starter: the hydration of a liquid starter is typically 75% and above. It has a loose, bubbly consistency with a lot of aeration. Liquid starter is more favorable for the development of lactic acid, which produces a smooth, creamy tang.
2. Stiff starter: the hydration of a stiff starter is usually around 65% and below. It has a dough-like consistency and forms a dome when rising. Stiff starter is favorable for the development of acetic acid, which produces a sharp, sour tang.

Which one is better? It comes down to a personal preference. Some people find mixing a batter consistency starter easier, while others prefer the ease of mixing a firm ball of dough. Personally, I prefer a liquid starter. As for the proportion of each acid in the final loaf, it can be manipulated regardless of the starter. 

It’s worth mentioning that professional bakers typically maintain both starters. However, if you’re just making a couple of loaves of sourdough a week, there’s no reason to necessarily do that. It’s easy to convert liquid starter to stiff and vice versa by making small adjustments to the water and flour ratio.

Tips for Making Gluten-Free Sourdough Starter

Ingredients

Sourdough starter requires only two simple ingredients:

• Flour: many gluten-free recipes call for several flours to make gluten-free sourdough starter, generally because each flour replicates some property in wheat-based baking. Some flours are higher in starch, while others contain more protein. High-starch flours produce light and airy baked goods, but don’t provide a lot of structure. High-protein flours produce dense and chewy baked goods, but provide a lot of structural stability. Combining them creates better texture in baked goods. My go-to is a combination of buckwheat flour and sweet white rice flour.
  • High-starch gluten-free flours: sweet white rice flour, white rice flour
  • High-protein gluten-free flours: buckwheat flour, quinoa flour, teff flour

Whichever flour(s) you decide to use, make sure they are unbleached and do not contain any chemicals. Enriched flours are fine to use. 

• Water: filtered or bottled water is best. Try to avoid chlorinated tap water as chlorine can cause the starter to die. To remove chlorine from tap water by evaporation, fill a bottle with tap water and let it sit uncovered for 24 hours. Can sourdough starter thrive with tap water? Yes, but it’s better to stack the odds in your favor. Also, room-temperature water is ideal – hot water will kill the microbes; cold water will slow the growth of microbes.

How to Make Gluten-Free Sourdough Starter 

• Find a warm place for the starter to grow. Yeast and lactobacilli bacteria tend to ferment most efficiently at 70°F/21°C – 75°F/25°C.  At this temperature range, they consume sugars from the dough with the least amount of byproduct, producing mild sourdough. The further away the temperature is from the optimal fermentation range, the more byproduct is produced in the dough. The more byproduct, the more sour the flavor. 

	Temperature Range	Fermentation Time	Flavor
Hot	82°F – 85°F (28°C – 29°C)	4 – 6 hours	base sourness
Warm	70°F – 75°F (21°C – 24°C)	6 – 12 hours	mild
Cold	35°F – 50°F (2°C – 10°C)	12+ hours	tangy sourness

I keep my gluten-free sourdough starter on the kitchen counter, away from the direct sunlight, with an ambient temperature around 75°F/24°C. If the ambient temperature of your kitchen/house is cooler than 70°F/21°C , you’ll need to create a warm spot. There are a few ways to do that:

• Turn the oven light on (not the oven!) and let the starter ferment in the oven. Use an ambient thermometer to keep an eye on the temperature.
• Place the starter in the microwave with the door just barely shut, so the light stays on. Use an ambient thermometer to keep an eye on the temperature.
• Put the starter next to a heating system, such as the fireplace, furnace, or water heater. Use an ambient thermometer to keep an eye on the temperature.
• Wrap the starter jar in a heating pad with an adjustable temperature.
• Use a proofer – Brod & Taylor is perhaps the most popular
• Prepare the sourdough starter container. To prevent any bad bacteria from developing, wash the container with hot water and soap, and rinse it thoroughly. Make sure there is no soap (or other chemical residue) left, potentially killing off the yeast. I like glass jars (inexpensive, clear, easy to sterilize) with straight sides (easy to monitor rising volume), wide mouth (easy to stir the starter), and a lid (for either a loose or an airtight cover). Weck jars are my go-to choice because they fulfil all those requirements and come with a glass lid that fits loosely but securely, allowing the sourdough starter to ‘breathe’ without drying out.
• Make the sourdough starter (day 1). Add 2 Tbsp./20 g buckwheat flour, 2 Tbsp./20 g sweet white rice flour, and ¼ cup/60 ml water into a glass jar, and mix until well combined. The consistency should be thick yet pourable. Cover the jar loosely with a lid or a damp tea towel, and allow it to sit at warm temperature for 24 hours. 
• Feed the sourdough starter (day 2). Discard half of the starter from the previous day. Feed the remainder with 2 Tbsp./20 g buckwheat flour, 2 Tbsp./20 g sweet white rice flour, and ¼ cup/60 ml water, and mix until well combined. Try to keep the jar as clean as possible – scrape down as much starter off the sides of the jar as possible, reincorporating it back into the mixture, and then wipe the top of the jar with a piece of paper towel. Cover the jar loosely with a lid or a damp tea towel, and allow to sit at room temperature for 24 hours.
• Feed the sourdough starter (day 3 – 7+). Repeat the process from day 2. Keep noting the consistency of the starter and add more/less water to get it to a thick yet pourable consistency. Sometime between days 5 and 10, you’ll notice that the starter has become puffy, is actively bubbling, and has a pleasant sweet-sour aroma. Typically, sourdough starter is ready for baking when it’s doubled in size a few hours after it’s been fed. To tell if your starter is doubling, use a glass marker or a rubber band on the outside of the jar to mark where the top of the starter is after feeding. After the starter reaches its peak, it will begin to lose its strength and fall back down, leaving streaks on the side of the container.

How to Maintain a Sourdough Starter

Once the starter is active, you can keep it indefinitely. Starters are often passed down in a family and kept for decades. However, to keep a healthy sourdough starter, you will need to maintain it (refresh it). There are a few ways to do that.

Short-Term Sourdough Starter Storage

• Keep it at room temperature. If you’re an avid baker and plan to use your starter weekly, you can keep it on the counter and feed it daily. 
• Refrigerate it. If you don’t plan on baking frequently, you can refrigerate a sourdough starter for about a week. Cold temperatures slow down yeast and bacteria activity, and will naturally extend how long a starter can sit between feedings. Before refrigerating the sourdough starter, discard a portion and give it a regular feeding. Allow it to sit at room temperature for roughly 1 hour before transferring it to the fridge. After about a week, refresh the starter – discard down and add fresh flour and water. Cover the jar with a lid and let the starter sit on the counter for ~12 hours before returning it to the refrigerator. Repeat the process every week. When the sourdough starter is young, it’s good to feed it once a week, but the more mature it is, the longer you can leave it in the refrigerator before feeding again. Starters have been known to be left for 10 days, 2 weeks, 1 month (or even longer) with no issue of coming back to full activity.

Long-Term Sourdough Starter Storage

• Dry it. If you’re not going to be using your starter for a while, you can dry it. Thinly spread a starter that is at its peak on a piece of parchment paper and allow it to dry out completely. Break it into little pieces, and store it in an airtight container. When you next want to use the starter, rehydrate it and feed it. To rehydrate a sourdough starter, add 1 Tbsp. dehydrated sourdough starter and 1 Tbsp./15 ml water into a glass jar and mix until all the starter is dissolved. You might need to let the starter sit fir a while. Once dissolved, add 2 Tbsp./20 g buckwheat flour, 2 Tbsp./20 g sweet white rice flour, and ¼ cup/60 ml water and mix until well combined. Continue feeding the starter until it has resumed regular activity levels.

Troubleshooting Tips

My sourdough starter isn’t doing anything.

Your starter won’t probably be showing any signs of activity within the first few days of fermenting. It’s completely normal. However, if your starter isn’t active within the first three days (that is, no visible bubbles, no rise, no sweet-sour odor), it could be because of:

• Low temperature: if the ambient temperature is too low (below 70°F/21°C), the fermentation will significantly slow down. Try to find or create a warm spot (above 70°F/21°C) or use more lukewarm water for feeding. Continue feeding the starter according to the instructions.
• Direct sunlight: the UV radiation sunlight emits can be harmful to yeast, depending on the species. So avoid direct sunlight.
• Insufficient feeding: the easiest way to revive a starter is to feed it more often. If there are no signs of bubbling or rising after day 3, begin to feed the starter twice a day (switching from a 24-hour schedule to a 12-hour schedule). 
• Chlorinated water: chlorine is used to sanitize (i.e. to kill bacteria, yeast, and fungi), so using filtered water is best. That being said, most modern water systems use a charcoal filtration process that radically reduces the need for chlorine. So, even straight from the tap the chlorine level is very low. If your local water department uses low-chlorine system, tap water is likely not an issue.

There is no need to throw away an inactive starter. If your starter isn’t showing any activity, make any necessary changes from the list above and continue feeding the starter according to the instructions.

My sourdough starter is active, but barely rising between feedings.

If your starter is not doubling or growing substantially in volume between feedings, it is not strong enough to leaven dough. Be patient and continue with regular feedings until the starter strengthens. You want to see consistent signs of fermentation day after day before you use the starter for leavening. 

My sourdough starter died after a lot of activity in the first couple of days.

In the first few days of building a sourdough starter, you will most likely see lots of bubbles and activity. This initial activity may suddenly stop and make it seem like something has gone wrong. This initial burst of activity is typically a different type of bacteria in the sourdough starter that will eventually be replaced by lactic acid bacteria. As you continue feeding and discarding your starter, it will slowly become more and more acidic. The other bacteria that might be present die off, which allows the wild yeast and lactic acid bacteria to take over, become more stable, and create an active gluten-free sourdough starter that is strong enough to leaven all manner of baked goods.

My sourdough starter is dead.

Sourdough starters are extremely resilient and it is unlikely that you actually killed your starter. However, there are a few things that will kill even the most mature starter:

• High-heat: yeast dies at 140°F/60°C and suffers at temperatures above 100°F/38°C. So, if you let your sourdough starter ferment in the oven or in the microwave, and then turn the appliance on, your starter will most likely die.
• No feeding: It’s fine to skip a feeding here and there, but if you forget about your starter for a few days, bad bacteria will take over. At that point, you will need to start over.

My sourdough starter has a weird smell.

The smells that are produced at each stage of sourdough development depend on the kind of flour you are using and the microbes who are working on the flour. 

• Alcohol/nail polish removal smell: when sourdough starter isn’t fed often enough, it will begin consuming discarded yeast, as well as its own waste, leading to the unpleasant aroma of alcohol or nail polish remover. The best way to prevent this from happening is to feed the sourdough starter more often. 
• Yeasty smell: when the sourdough is at the peak of it’s rise, it will smell yeasty-bready. It’s a sign that the starter is ripe and well-fed.
• Tangy/vinegary smell: the more acetic acid the starter contains, the more tangy it will smell. To reduce the assertive sour smell, feed the starter more often.

There is dark liquid on top of my starter.

The liquid is called hooch and it’s the alcohol given off as wild yeast ferments. Hooch is formed and thrown off when a starter is fed too little, and too infrequently. If you have just a bit, stir it in and feed the starter. If you have a lot (more than 1 inch/2.5 cm in a quart/946 ml jar, pour it off, replace it with water, and then feed the starter. You can prevent hooch by keeping your starter fed well and often.

My sourdough starter is developing mold.

While mold on a sourdough starter is fairly rare, it does happen from time to time. Mold can occur on the surface of the starter or on the jar itself. Its appearance can range from pink and white to green, dark brown, and black. The cause is usually some sort of contamination with food or weakened yeast due to a forgotten feeding. If you see any type of mold, throw the starter out and start over. There is no way to fix or salvage a moldy starter. 

Sourdough Starter Recipes

The great thing about gluten-free sourdough starter is that you can use it instead of commercial yeast in any bread recipe. Not all sourdough breads are sour; in fact, some barely have any note of sourness at all. This all depends on how you feed your starter and when you use it. 

Recipes coming soon!