Potato Flake Sourdough Brownies (quick or ferment)

These potato flake sourdough brownies are perfectly fudgy and have that signature crackly top that everyone loves in a brownie!  Using a potato flake sourdough starter takes these brownies to a new level, making the grains more digestible and full of flavor! This is a great make ahead recipe as it can be refrigerated for up to 24 hours and baked right before serving! Add this recipe to your potato flake sourdough discard recipe favorites! 

This post contains affiliate links, which means I make a small commission at no extra cost to you. See my full disclosure here.

Tools you will need:

Large bowl

Small or Medium sauce pan

Whisk

Rubber Spatula

9×9 baking pan

Parchment paper

Ingredients:

All-purpose flour: All-purpose flour provides structure, but be careful not to over-mix. The more the dough is mixed, the more gluten is developed. Gluten is not needed for brownies because we want a fudgy brownie, not cake like brownie. Whole wheat flour can be used in place of all purpose flour, but I wouldn’t use bread flour.

Granulated sugar & Dark brown sugar: Using both granulated sugar and dark brown sugar adds complexity to the sweetness of the brownies. 

Unsalted butter: If you only have salted butter on hand, that perfectly okay! Just be sure to eliminate the salt in the recipe. 

Semisweet chocolate chips: Semisweet is the best chocolate for the best balance of sweetness in a brownie. Of course, other types of chocolate, like dark or milk chocolate,  can be used. 

Cocoa Powder: Cocoa powder enhances the chocolate flavor, making the brownies rich and indulgent.

Vanilla Extract: Vanilla add delicious flavor to these brownies. It enhances the flavor of the cocoa and chocolate. 

Large Eggs: Eggs are one of the main liquids in this recipe.  

Potato flake sourdough starter: This type of starter uses instant potato flakes, warm water, sugar, and commercial yeast to cultivate wild yeast from the environment. Once it is established, commercial yeast is no longer needed. It is different from the traditional sourdough starter made from flour and water. It can sometimes be confused with an Amish friendship bread starter. The starter can be kept active by regular feedings or stored in the fridge when not in use. For this recipe it can be an active (recently fed) starter or can be discard starter (not recently fed or used directly out of the fridge.) 

Salt: If you use salted butter, be sure to eliminate the salt! Sea salt or table salt are both great options.

How to make the perfect potato flake sourdough brownies

Preparing the Butter and Sugar Mixture

Combine Sugars and Butter: In a medium saucepan over medium heat, combine the 1/2 cup of sugar, 1/2 cup of brown sugar, and butter. Heat and stir until the butter is melted and the sugars are well combined. This is one of the most crucial steps to getting a good brownie with the crackly top.  

Add Chocolate Chips: Once the butter is melted, take the saucepan off the heat and add the chocolate chips. Stir until the chocolate is fully melted and the mixture is smooth.

Cool the Mixture: Place the mixture in the fridge to cool slightly. Be cautious not to leave it in too long, as the butter will solidify. The goal is to bring the mixture to a slightly warm temperature.

Mixing the Wet Ingredients

Beat the Eggs: In a large mixing bowl, beat the eggs for one minute until they are light and well mixed. (This can be done with a hand whisk or in a stand mixer)

Add Vanilla and Starter: Mix in the vanilla extract and the 1/4 cup of starter. The starter can be recently fed or one that has been sitting in the fridge.

Incorporate Cocoa Powder: Add the cocoa powder and whisk to combine.

Combining Mixtures

Check Temperature: Ensure the butter and chocolate mixture is not hot. Warm will be fine, but hot will cook the eggs and kill the active sourdough starter.

Mix Together: Combine the butter mixture with the egg mixture, stirring until just combined.

Add Flour: Add the all-purpose flour and mix until you do not see any more white flour. Avoid over-mixing to keep the texture fudgy.

Fermentation (Optional)

Cover and Refrigerate: Cover the mixture with plastic wrap and place it in the fridge for at least 10 hours, up to 24 hours, for a long fermentation process. This may seem like a long time, but cold will slow down the fermentation process. This step enhances the flavor, texture, and makes the grains more digestible, thanks to the wild yeast in the sourdough starter.

Jumpstart Fermentation: If you want to speed up the fermentation, leave the batter at room temperature for a few hours before refrigerating.

Baking the Brownies

Prepare the Pan: The next day, line the bottom of a 9×9 pan with parchment paper and spray with cooking spray.

Spread the Batter: Pour the thick batter into the prepared pan. If the batter has fermented, it will be thicker – this is normal. Spread it as evenly as possible.

Bake: Bake the brownies in a preheated oven at 350°F for about 40 minutes. At 35 minutes, check to see if the middle is set.

Cool Completely: Allow the brownies to cool completely in the pan before slicing. This helps them set and makes cutting easier.

Tips for Perfect Brownies

• Don’t Over-Mix: After adding the flour and cocoa powder, do not over-mix the batter. Over-mixing introduces air, resulting in a cakey texture.
• Avoid Over-Baking: Be careful not to over-bake the brownies. They should remain fudgy in the center.
• Cutting Warm Brownies: If you need to cut the brownies while they are still warm, use a plastic knife and saw-like strokes for cleaner cuts.

Optional Add-Ins:

Feel free to personalize your brownies with these optional add-ins:

• Nuts: Crushed walnuts, peanuts, almonds, or pecans.
• Extra Chocolate: Chocolate chips, peanut butter chips, or chocolate chunks.
• Dried Fruit: Cranberries, raisins, or other dried fruits.

Fermentation for this potato flake starter recipe:

Long Fermentation

Fermenting the brownie batter with an active starter for 10 to 24 hours allows the wild yeast and bacteria in the potato flake sourdough starter to break down complex carbohydrates and proteins in the flour. This process not only enhances flavor but also improves the nutritional profile and digestibility of the brownies. The slight tang from the sourdough complements the sweetness and richness of the chocolate, creating a more balanced and sophisticated dessert.

Room Temperature and Fermentation

Leaving the batter at room temperature or in a warm place for a few hours before refrigerating can jumpstart the fermentation process. This is especially useful if you’re short on time but still want to benefit from the health benefits and flavor development that fermentation provides.

Don’t Have Time to Ferment

Sometimes planning ahead for a chocolate craving just isn’t possible. This recipe can be made without long fermenting and will still be super delicious! The purpose of the fermentation is mainly to ferment the grains to make it more easy to digest. It is not necessary to wait the long fermenting time if you need the brownies ASAP!

Common Questions and Troubleshooting

Why is My Batter So Thick?

A thick batter is normal, especially after fermentation. This is due to the flour absorbing moisture and the natural thickening from the sourdough starter. Simply do your best to spread the batter evenly in the pan.

Can I Use a Different Type of Chocolate?

Yes, you can use dark chocolate or even milk chocolate if you prefer a sweeter brownie. Dark chocolate provides a richer, more intense flavor. Semisweet creates the perfect “middle of the road” brownie, as far as sweetness goes.  

What if I Don’t Have a Potato Flake Starter?

If you don’t have a potato flake sourdough starter, you can easily make your own! The starter ingredients are: warm water, potato flakes, sugar and commercial yeast. I explain exactly how to make your own potato flake starter in this post. You can use this starter to make all types of things! Grab your loaf pans and make some homemade sourdough bread. Cinnamon rolls, dinner rolls, and banana nut muffins are some of our favorite potato flake sourdough recipes! I also have several discard recipes you might enjoy too!    

You’re sure to love these potato flake sourdough brownies!

Making potato flake sourdough brownies is a delicious way to use up excess sourdough starter and enjoy a rich, fudgy dessert. The process is straightforward, with the optional step of fermentation adding a unique twist to traditional brownies. Remember to handle the ingredients carefully, especially the mixing and baking times, to achieve the best texture and flavor. Whether you’re an experienced baker or trying this for the first time, these brownies are sure to impress and satisfy your sweet tooth. 

Pin for later and share with a friend!

Add all of my recipes to your meal planning app!

Use my link to get 20% off your first year of using plan to eat! Not only do you get an amazing meal planning tool, but you also will get ALL of my recipes from the blog added to your meal planning app. PLUS you will gain access to exclusive recipes not found on the blog!

Potato Flake Sourdough Brownies

These potato flake sourdough brownies are perfectly fudgy and have that signature crackly top that everyone loves in a brownie!  Using a potato flake sourdough starter takes these brownies to a new level, making the grains more digestible and full of flavor!

5 from 2 votes

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 40 minutes mins

Fermenting 12 hours hrs

Total Time 13 hours hrs

Course Dessert

Servings 9 brownies

Equipment

• Large bowl
• Small or Medium sauce pan
• Whisk
• Rubber Spatula
• 9×9 baking pan
• Parchment Paper

Ingredients

  

• ⅔ cups all-purpose flour
• ½ cup granulated sugar
• ½ cup brown sugar sugar
• ½ cup unsalted butter If using salted butter remove the ¼ teaspoon of salt
• 7 ounces melted dark chocolate or semisweet chocolate
• 2 tablespoons cocoa powder
• 1 teaspoon vanilla extract
• 2 large eggs
• ¼ cup potato flake starter
• ¼ teaspoon salt if using unsalted butter

Instructions

 

• In a medium saucepan over medium heat, combine white sugar, brown sugar, and butter. Heat and stir until the butter is melted. Take off heat and add chocolate chips. Stir until all melted together. Place in the fridge to cool slightly until read to mix with the rest of the ingredients (Don’t forget and leave it in there or the butter will get hard. This is just to help cool it down.)
• In a large mixing bowl beat the eggs for one minute. Next, mix in the vanilla. Add in the potato flake starter and mix together. It can be a recently fed starter, or a starter that has been sitting in the fridge.
• Add in the cocoa powder. Whisk to combine.
• Make sure the butter mixture is not hot. If it is warm, that is okay. Mix with the egg mixture until just combined.
• Add in the flour and only mix until you do not see any more white. Stop as soon as it is incorporated.
• Cover with plastic wrap and place in the fridge for at least 10 hours, up to 24 hours for a long fermentation of the grains. If you want to jump start the fermentation before placing it in the fridge, leave the batter out at room tempature for a few hours and then place it in the fridge to finish the fermentation.
• If you do not want to long ferment your brownies, skip this step and jump right into the next step.
• Prepare a 9×9 pan by lining the bottom with parchment paper and oiling the sides.
• Pour the thick batter into the prepared 9×9 pan. If fermented, it becomes even thicker, this is okay! Do your best to spread the mixture out into an even layer.
• Bake 40 minutes at 350℉ in the prepared 9 X9 pan. Set a timer for 35 minutes to check and see if the middle is set. When it is baked to your doneness preference, remove from the oven.
• Allow to cool completely before slicing and serving. This will help it set up and keep them from falling apart as easily.

Notes

Don’t over-mix after adding the dry ingredients or else the texture of the brownies will change!
Don’t over-bake or else the inside of the brownies will become more cake-like rather than staying fudgy.
I repeat Do NOT over beat your batter once the flour is added. It  will give you cake-like textured brownies.
If you want to cut your brownies while they are still warm, use a plastic knife and use small saw-like strokes for cleaner cut lines.

Cool down your butter mixture quicker by sticking it in the fridge for a few minutes, but don’t leave it for too long or the butter will solidify again! 

Keyword potato flake starter recipes