Sourdough Protein Bars (15g Protein + Great for Active Starter or Discard)

If you haven’t heard already… you probably need more protein in your diet 😄. I’ve got a great option for you that doesn’t include eating a container of cottage cheese…lol.

These sourdough protein bars are one of my favorite ways to use extra sourdough starter or discard and they come together quickly with simple ingredients..

These bars have become one of my bakery’s most popular items — and for good reason. They’re soft, filling, and actually satisfying.

Each bar has 15g of protein or more, making them perfect for:

• a quick breakfast
• post-workout snack
• grab-and-go meal

---

Why You’ll Love This Recipe

• Uses sourdough starter or discard
• High in protein (15g+ per bar)
• Easy to customize flavors
• Stores well for weeks
• Great for meal prep

---

Ingredient Notes (important for success)

For best results, I highly recommend using:

👉 Unflavored, unsweetened protein powder

Flavored or sweetened powders can:

• throw off the flavor
• change the texture
• require adjusting the honey

I personally use beef isolate protein for baking, but any clean, unsweetened protein will work. I also mix whey and beef isolate and they come out great. Just look for single ingredient protein powders. In my opinion, those work best for baking.

---

Flavor Variations (this is where it gets fun)

One of my favorite things about this recipe is how customizable it is.

Keep mix-ins to about 2 cups total, and try combinations like:

Chocolate Espresso

• walnuts
• chocolate chips
• chocolate-covered espresso beans

White Chocolate Pistachio

• pistachios
• white chocolate chips

Peanut Butter Chocolate Chip

• peanut butter
• chocolate chips

S’mores

• chocolate chips
• graham crackers
• mini marshmallows

Apple Cinnamon

• walnuts
• dried apples
• cinnamon

Banana Nut Bread

• mashed banana
• walnuts
• cinnamon

Pumpkin Spice Chocolate Chip

• pumpkin
• pecans
• chocolate chips
• pumpkin spice

Blueberry Walnut

• walnuts
• pumpkin seeds
• freeze-dried blueberries

---

🥣 Step-by-Step Overview

If this is your first time making these, here’s exactly what it should look like at each step:

Step 1: Mix the Base

Combine honey, protein powder, water, vanilla, oil, and salt.

👉 It will look thick and a little dry at first — that’s normal.

---

Step 2: Add Starter + Eggs

Mix in your sourdough starter and eggs.

👉 This is where the mixture starts to loosen up and come together.

---

Step 3: Add Oats + Mix-Ins

Stir in oats, chia seeds, and your flavor add-ins.

👉 Now it should look like a thick, scoopable batter.

---

Step 4: Fill the Molds

Scoop into silicone molds or a baking dish.

👉 I use these silicone bar trays — they make shaping and removal really easy.

---

Step 5: Bake

Bake at 300°F for about 45-50 minutes.

👉 Edges will set first — centers should be firm but not dry.

---

Step 6: Cool

Let cool before removing.

👉 If you try to take them out too early, they’ll fall apart.

Tips for Best Results

• The mixture will be thick — this is normal
• Mix protein powder well to avoid lumps
• Silicone molds work best (easy removal + even shape)
• Don’t skip cooling time — they will fall apart if removed too early

---

Storage Tips

These bars store really well, which makes them perfect for meal prep.

• Refrigerate for up to 3 weeks
• Wrap individually in parchment OR
• Vacuum seal for best freshness

Vacuum sealing keeps them just as fresh as the day you made them. If you want a good bag for vacuum sealing, these work perfect!

👉4 x 8 Inch Vacuum Sealer Bags

---

Sourdough Tip

This recipe works great with:

✔ active starter
✔ discard

It’s a great way to use extra starter without wasting it.

---

Final Thoughts

If you’re baking sourdough regularly, this is one of those recipes that just makes sense to have on hand.

Simple, filling, and easy to customize — and a great way to use what you already have in your kitchen.

---

If you need a strong starter to get started…

I use the same organic sourdough starter in my own kitchen every week. If you want to skip the trial-and-error, you can find it here.

👉Organic Sourdough Starter

Continue Your Sourdough Journey

👉Simple Farmhouse Sourdough Bread Recipe (Beginner-Friendly + Digestible)
Learn the full beginner-friendly process for mixing, fermenting, shaping, and baking sourdough bread.

👉Beginner Sourdough Mistakes: Why Your Loaf Is Flat, Dense, or Gummy (And How to Fix It)
Common reasons sourdough loaves turn out flat, dense, or gummy — and how to fix them.

👉My Exact Sourdough Baking Schedule (How I Make It Work In My Home Bakery)
See how I manage fermentation, shaping, and baking when making dozens of loaves each week.

👉Browse All Blog Posts

If you try this recipe, I’d love for you to leave a rating below ⭐⭐⭐⭐⭐— it helps others and supports my small bakery.

Frequently Asked Questions

Can I use sourdough discard for protein bars?
Yes, this recipe works great with both active starter and discard.

How much protein is in each bar?
Each bar contains about 15g of protein or more, depending on your mix-ins.

How long do sourdough protein bars last?
They can be stored in the refrigerator for up to 3 weeks.

Can I freeze these protein bars?
Yes, they freeze well and can be thawed as needed.