Do you keep a sourdough starter in your kitchen? If you answered yes, then chances are you are always looking for new ways to use up that discard starter after you refresh it. One great way to use up discard starter that may be a day or two old is baking quick breads and muffins with it!
This sourdough banana bran muffins recipe is one of my creations for substituting discard starter into a previously non-sourdough recipe. Essentially you just use the discard starter as a substitute for some of the flour and liquid in the original recipe. But don’t worry, I’ll walk you through all the substitutions! I’ll also give you some basic guidelines for how to experiment with starter as a substitute in your baking.
This banana bran muffins recipe is an easy (and tasty!) way to use up that discard starter. I hope this not only gives you a new recipe to try, but some ideas for how else you might substitute discard starter into other recipes you like to bake!
If you aren’t currently keeping a starter and you want to get one going, or if you want to read more about the basics of keeping, feeding, and using a sourdough starter, check out the article I’ve written on the what, why, and how of sourdough starter.
A couple of my other go-to recipes for using up discard starter are the cracker and oatmeal pancake recipes below.
How to Substitute Sourdough Starter in a Recipe
I have found a lot of great baking substitution advice on the Wild Yeast Blog, particularly for quick breads and muffins. The author dissects the use of sourdough in different types of recipes and talks about ways to make substitutions in those recipes. There are also some excellent recipes featured over there! This site has been a great resource in my sourdough baking adventures. I highly recommend you take a look for yourself.
When substituting sourdough starter into a recipe, the key substitutions to calculate are for flour and liquid. Basically, you substitute all or a portion of the flour and liquid in the original recipe with your starter, and voila!
If you are in a pinch to have enough liquid volume in a recipe to substitute with your starter, you can also consider replacing some of the fat like oil or butter.
One last tip to keep in mind when experimenting with a sourdough substitution. If the bread (or muffin, etc) you are baking turns out too dense, try adding 1/2 – 1 tsp of baking soda to the recipe. The baking soda reacts with the acid in the starter causing additional rising when baking. This banana bran muffins recipe already includes some baking soda. But I wanted to call this out specifically in case you decide to experiment beyond this exact recipe 🙂
Some Numbers to Keep in Mind
- The starter that I keep is a 100% hydration starter, which means equal parts by weight of flour and water. So in 100g of starter, there are 50g flour, and 50g water.
- Many baking recipes don’t include weights, but just measurements. Since we need to substitute by weight, it is helpful to note that 1 cup of water = 237g and 1 cup of all purpose flour is ~120g.
Picking a Bran Muffins Recipe to Work With
I decided to work off this recipe from Eating Well. I chose this recipe for a couple reasons:
- Ingredients. I love recipes that use enriched ingredients like buttermilk, and in my opinion cinnamon makes anything better.
- Texture. I like the texture of quick breads and muffins that use oil as the fat.
- Flexibility. Since it includes 1 cup of buttermilk, that gives me the flexibility I need with the liquid component for subbing in sourdough starter. Not all recipes include this volume of liquid!
Making the substitutions
In the original
Flour in the original recipe:
- 3/4 cup all purpose flour = 90g
- 1 cup whole wheat flour = 152g (Bob’s Redmill stone ground whole wheat flour)
After converting the measurements to weight, this bran muffins recipe has 242g of flour in total.
Liquid in the original recipe:
- 1 cup buttermilk = 4 tablespoons powdered buttermilk plus 1 cup water (237g)
In order to keep the buttermilk but substitute in the liquid portion of my starter, I switch to powdered instead of liquid buttermilk. I always keep a container of Saco powdered buttermilk on hand for baking recipes like this! Subbing in powdered buttermilk gives me 237g of water to work with in my substitution. If you can’t find powdered buttermilk, you can use powdered milk instead. It will still add a nice enrichment to your batter. And any acidity that is needed from the buttermilk will be covered with the addition of the starter.
In the sourdough version
- 300g sourdough discard starter (150g flour + 150g water)
- 92g whole wheat flour (242g of flour in the original recipe minus 150g of flour from the starter leaves us with 92g of flour to add in)
- 87g water (237g of water in the original recipe minus 150g of water from the starter leaves us with 87g of water to add in)
Now let’s put it all together for the final sourdough banana bran muffins recipe! Compared to the original recipe, I also reduced the sugar, and substituted applesauce for the oil. Just for an extra healthy twist on these bran muffins 🙂 And bonus – they still taste A-Mazing! I hope you love these muffins as much as we do! I also hope this recipe gives you some ideas for how to use that discard starter in new ways. Happy baking!
- 3-4 mashed ripe bananas (about 1 cup)
- 70 g applesauce (about ¼ cup, or substitute oil by volume (¼ cup) – 56g for vegetable oil, 60g for EVOO)
- 2 large eggs
- 60 g brown sugar
- 300 g discard sourdough starter
- 90 g filtered water
- 1 tsp vanilla extract
- 60 g wheat bran (I like Bob's Redmill brand)
- 95 g whole wheat flour
- 25 g powdered buttermilk (I keep Saco or Bob's Redmill brands on hand for baking)
- 1½ tsp baking powder
- ½ tsp baking soda
- 1 tsp ground cinnamon
- ¼ tsp salt (table salt)
- 50 g raisins
- 75 g walnuts (toast if desired)
- Preheat the oven to 400°F.
- Mash the bananas. If they were frozen, transfer to a fine colander to drain out any excess liquid.
- Add the applesauce to the colander as well to also drain excess liquid.
- Whisk together the eggs and brown sugar.
- Add the vanilla, water, and starter and whisk until combined.
- Add the mashed banana and applesauce (after straining excess liquid).
- Mix in the wheat bran.
- Whisk together the remaining dry ingredients and add to the wet ingredient mixture above – mix just until combined.
- If adding walnuts and/or raisins, mix them in now.
- Let the batter sit for about 5 minutes – it should thicken up a bit and start to get a little bubbly.
- While the batter is resting, prep 12 muffin tins with liners, or spray with nonstick spray.
- Spoon the batter into the tins, you can fill most of the way to the top.
- Bake @ 400°F for about 20 minutes, until springy to the touch and a toothpick inserted into the center comes out clean.