Sourdough discard low iodine banana muffin, light and fluffy coming out of muffin tin
Home » Blog » A Favorite Sourdough discard low iodine banana muffins

A Favorite Sourdough discard low iodine banana muffins

—

by

Erin
in

These sourdough discard low iodine banana muffins are soft, naturally sweet, and made specifically for a low-iodine diet — using sourdough discard, lard instead of butter, and non-iodized salt throughout.

This low iodine banana muffin recipe was adapted from Little Spoon Farm. It was adapted FROM a standard recipe INTO a low-iodine version, with notes for converting back if not on the diet. Still an amazing muffin, they do not last in the kitchen. PS I am not a dietitian or a dr. These are just my experiences, please consult your dr if on a low iodine diet.

I reworked this recipe originally for our family’s low iodine diet. If you’re in that situation, the lard and egg white substitutions work perfectly — but please check with your doctor for your specific dietary needs. Always check your labels, not every product is created equal.

I do NOT earn commission on any of these links. I am sharing what has worked on our diet for cancer radiation treatment. We loved this one so we still make this recipe as we love it!

Truly The Sourdough Discard Low Iodine Banana Muffins

A delightful sourdough discard low iodine banana muffin recipe featuring wheat germ (instead of nuts) and loaded with ripe bananas! You’ll appreciate how soft these are, with a touch of crispness on top from the addition of bakers’ molasses (Low iodine option). They’re perfect for making ahead for busy mornings!

Low iodine Sourdough discard muffin batter scooping into bowl

A Few Notes On Sourdough Discard Low Iodine Banana Muffin Ingredients

Notes on specific ingredients:

I learned so much about dairy when we got the word we were going ahead with treatment. Dairy is excluded on a low-iodine diet for two main reasons: iodine is often added to cattle feed, and iodine-based sanitizers are commonly used to clean udders and equipment during milking. Both can transfer into the milk, which is why dairy products carry more iodine than naturally low-iodine foods like fruit.

Sourdough discard is something you really don’t see on low iodine recipes. I wanted my other half to have something special since he was going to miss out on his daily cheese intake! I use a a lot of discard in my no waste baking. Not only does the discard a flavor it adds moister and texture to these muffins.

I have become such a fan of lard after raising our own pigs. The leaf lard in baking is truly amazing. So when we needed a dairy free option this was the one I reached for. Since the lard landscape has changed so much, make sure you read the labels and make sure you have real lard or go straight to the butcher.

✅

LID Safety Breakdown

Checked against ThyCa.org Low-Iodine Diet guidelines — read the cautions, not just the checkmarks

Wet Ingredients

✔ Kentucky lard — 8 tbsp (113g) LID Safe

Rendered pork fat with no iodine and no dairy. ThyCa permits animal fats. If substituting butter for a dairy-free version, butter is NOT LID-safe — stick with lard or a plant-based fat instead.

✔ Organic white sugar — ¾ cup (150g) LID Safe

Plain refined sugar contains no iodine. ThyCa permits all plain sugars on the LID.

✔ Unsulfured baker’s molasses — ¼ cup (50g) LID Safe

Unsulfured molasses contains no added iodine compounds. ThyCa permits plain molasses on the LID.

⚠ Egg whites — 3 large Check Your Plan

Egg whites alone (without the iodine-concentrated yolk) are the ThyCa-recommended way to use eggs on a strict LID — this recipe already reflects that. If you are not iodine-restricted, whole eggs work fine, as noted.

✔ Ripe bananas — 3 (350g, about 1 cup mashed) LID Safe

Fresh bananas are naturally low in iodine and explicitly permitted on the LID per ThyCa’s fruit guidelines.

✔ Vanilla extract — 1 tsp (5g) LID Safe

Pure vanilla extract contains no iodine. ThyCa permits standard extracts and flavorings in small amounts like this.

✔ Sourdough discard — 1 cup (250g) LID Safe

A fermented culture of just flour and water — no dairy, no commercial yeast additives. Confirm your starter was built with non-iodized salt.

Dry Ingredients

✔ Organic all-purpose flour — ¾ cup (180g) LID Safe

Unbleached, unenriched, non-bromated flour (like Bob’s Red Mill or Sir Galahad) has no iodized dough conditioners. ThyCa permits plain wheat flour.

✔ Organic wheat flour — ¼ cup (60g) LID Safe

Plain whole wheat flour with no iodized additives. Permitted on the LID.

✔ Baking powder — 2 tsp LID Safe

Most baking powders are LID-safe, but some contain additives — always check that your brand doesn’t list iodine-based ingredients on the label.

✔ Baking soda — ½ tsp LID Safe

Plain sodium bicarbonate with no iodine. ThyCa permits baking soda on the LID.

✔ Kosher salt — 1 tsp (5g) LID Safe

Kosher salt is not iodized — the key distinction from table salt. ThyCa specifically recommends switching to kosher or non-iodized salt on the LID. Always double check your specific brand’s label.

✔ Pure Ceylon cinnamon — 2 tbsp LID Safe

A plain ground spice with no iodine. ThyCa permits standard spices including cinnamon.

⚠ Wheat germ — 1 cup (75g) Check Your Plan

Plain wheat germ contains no iodine and isn’t flagged by ThyCa as a restricted grain product. It’s noted here simply because it’s a less common LID ingredient — confirm it fits your specific medical team’s plan if you have additional restrictions.

ℹ️ Always verify labels before use, especially baking powder brands. Guidelines from ThyCa.org. Consult your endocrinologist or nuclear medicine team for personal guidance — especially if substituting any ingredient marked above.
Sourdough discard low iodine banana muffin, light and fluffy coming out of muffin tin

Low Iodine Banana Muffins (Dairy-Free, Sourdough Discard)

Print Recipe Pin Recipe
Prep Time 20 minutes
Cook Time 20 minutes
Servings: 12
Course: Breakfast
Cuisine: American
Ingredients Equipment Method

Ingredients
  

Dry Ingredients
  • 3/4 Cup Organic White Flour You can use AP Flour, I Liker Sir Galahad
  • 1/4 Cup Organic Wheat Flour
  • 2 tsp Baking Powder Check labels
  • 1/2 tsp Baking Soda Check labels
  • 1 tsp Kosher Salt Must Check label to make sure the brand does not use iodine
  • 2 tbsp Organic Ceylon Cinnamon Use what you have for Cinnamon this is just my preference
  • 1 Cup Wheat Germ Check with Dr. and Label. Omit if not wanted
Wet ingredients
  • 8 tbsp Kentucky Lard – pure lard Can substitute coconut oil
  • 3/4 cup Organic White sugar
  • 1/4 cup Unsulfured molasses must be unsulfured for low iodine
  • 3 lrg Egg whites – the whites only no yolks on low iodine diet
  • 3 lrg Very ripe banana makes about one cup mashed
  • 1 tsp Vanilla extract measure with Love
  • 1 cup Sourdough discard about 250 grams, can be discard or bubbly

Equipment

  • 1 Mixing Bowl
  • 1 Set of measuring cups
  • 1 Set of Measuring Spoons
  • 1 Mixing Spoon
  • 1 Hand mixer optional

Method
 

  1. Preheat oven to 350°F (176°C) lightly grease a 12-count muffin tin or use a liner of your choice. (mine made a baker's dozen)
  2. Whisk (or sift if you have a sifter) dry ingredients: the 2 flours, wheat germ, cinnamon, salt, baking powder, and baking soda together in a bowl and put it aside
  3. Utilize a different bowl for wet ingredients, use a fork to squash the bananas until smooth.
  4. Melt the lard or butter in a mixing bowl or use a pan on the stove let it cool a bit.
  5. Add remaining Wet ingredients to mashed banana: the egg whites, cooled lard, sourdough discard, and vanilla extract and mix until combined.
  6. Add the wet ingredients to the dry ingredients and mix until just combined. (Do not over mix!) It will be thick.
  7. Bake for 20-25 minutes (check at 15min) or until a toothpick inserted into the center comes out clean. Transfer to cooling rack. When cool they pop right out of the tin if it is greased 🙂

FAQ: Sourdough discard low iodine banana muffins

Can you eat bananas on a low-iodine diet?

The Thyca cookbook, page 9, states the LID goal is to “limit the quantity of foods moderate in iodine to (5-20 mcg per serving)”.
Bananas, according to the National Institute of Health, is 0 : https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/ Again I am not a Dr. So please check with your medical professional.

What fruits can I eat on a low-iodine diet?

According to the 9th edition of the LOW Iodine Cookbook “Fruit, fresh, frozen, or jarred, salt-free and without red food dye; canned in limited quantities; fruit juices” Dried fruit: cherries, blueberries, raisins, etc. (watch for food coloring and salt) Fresh fruit: apples, grapes, bananas, melon, peaches, etc.

Can I substitute the wheat germ if I have a nut allergy too?

Yes — nuts are actually allowed on a low-iodine diet according to ThyCa, but I used wheat germ instead for the fiber boost and nutty flavor. If you have a nut allergy on top of LID, wheat germ itself is a safe substitute, since it’s listed as an approved ingredient in many ThyCa cookbook recipes

Can I freeze these muffins?

Yes! Let them cool completely. Then flash freeze for one hour. Wrap individually, place in them all in an air tight container. When ready to eat, either thaw at room temp or pop them in toaster oven or microwave for a warm treat.

Looking for other Low Iodine recipes?

Stack of soft homemade flour tortillas made with sourdough discard, LID-safe and thyroid cancer diet friendly

Low iodine sourdough discard tortillas

Reference

Effects of iodine intake and teat-dipping practices on milk iodine concentrations in dairy cows” — Journal of Dairy Science, ScienceDirect, 2011.
URL: https://www.sciencedirect.com/science/article/pii/S0022030211006928

Thyca.org Cook Book:
https://thyca.org/wp-content/uploads/Cookbook.pdf