Keto lemon poppy seed loaf is a moist, tangy take on the coffee-shop classic, made with coconut flour and erythritol instead of sugar and wheat. Fresh lemon zest and juice run through the batter, and a simple cream glaze soaks into the warm top. It's the guilt-free companion for a hot cup of coffee.
There’s something magical about a bright, zesty slice of lemon loaf alongside a hot cup of coffee. My husband’s love for the famous Starbucks version inspired this recipe, but I knew I could create a version without all the sugar and carbs. This Keto Lemon Poppy Seed Loaf is everything you love—moist, tangy, and bursting with fresh lemon flavor—but made with wholesome ingredients you can feel good about. It’s the perfect treat to bake at home and bring along on your next coffee run!
Ingredients
• For the Loaf
• ½ cup / 64g (2.26 oz) coconut flour
• ½ cup / 96g (3.39 oz) granular erythritol
• 2 teaspoons / 8g (0.28 oz) baking powder
• ¼ teaspoon / 1g (0.04 oz) xanthan gum
• ¼ teaspoon / 1.5g (0.05 oz) salt
• 3 large eggs, room temperature
• ½ cup / 120g (4.2 oz) sour cream, room temperature
• 1 tablespoon / 15ml (0.5 fl oz) avocado oil
• ½ teaspoon / 2.5ml (0.1 fl oz) vanilla extract
• 1 tablespoon / 9g (0.32 oz) poppy seeds
• 1 large lemon, for zest and juice
• For the Optional Glaze
• ¼ cup / 60ml (2 fl oz) heavy whipping cream
• ¼ cup / 48g (1.69 oz) confectioners’-style erythritol
Instructions
1. Preheat your oven to 325°F / 165°C. Prepare a 9×5-inch loaf pan by lining it with parchment paper, leaving an overhang on the sides to act as handles for easy removal.
2. In a medium bowl, whisk together the dry : coconut flour, granular erythritol, baking powder, xanthan gum, and salt to break up any clumps.
3. In a separate large bowl, whisk the eggs until light and frothy. Add the sour cream, avocado oil, and vanilla extract, and whisk until the mixture is smooth and fully combined.
4. Gradually pour the dry into the wet , stirring with a spatula until just combined. Do not overmix. Gently fold in the poppy seeds, lemon zest, and fresh lemon juice.
5. Pour the batter into the prepared loaf pan and smooth the top with your spatula. Bake for 50-60 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean.
6. While the loaf bakes, prepare the glaze. In a small bowl, whisk the heavy whipping cream and confectioners’-style erythritol until smooth and the sweetener has completely dissolved. Set aside.
7. Remove the loaf from the oven and let it cool in the pan for 15 minutes. Pour the glaze evenly over the warm loaf. Allow the loaf to cool completely in the pan before using the parchment handles to lift it out, slice, and serve.
Nutritional Information
• Yield: 8 servings
• Serving Size: 1 slice
• Calories: 150kcal
• Fat: 12g
• Carbohydrates: 5g
• Protein: 4g
• Net Carbs: 2g (0.07 oz)
• Please note that is an estimate and can vary based on the exact and brands used.
Pro Tips
• for the Perfect Lemon Loaf
• Ensure your eggs and sour cream are at room temperature. This helps the batter mix together smoothly and results in a more tender, evenly baked loaf.
• Coconut flour is very absorbent. Mix the batter only until it is just combined to avoid a dry or dense texture.
• For an extra burst of lemon flavor, poke small holes in the top of the warm loaf with a toothpick before pouring over the glaze. This allows the tangy glaze to seep into the cake.
• Store leftovers in an airtight container at room temperature for up to 3 days or in the refrigerator for up to a week. This loaf tastes fantastic when chilled!
FAQ
Q: Can I use a different flour instead of coconut flour
A: This recipe is specifically developed for coconut flour, which is highly absorbent and cannot be substituted 1:1 with other flours. Using a different flour would require significant adjustments to the wet ingredients to achieve the correct texture.
Q: Why do my ingredients need to be at room temperature
A: Using room temperature eggs and sour cream helps the batter mix together smoothly and evenly. This creates a better emulsion, leading to a more tender and uniformly baked loaf.
Q: How do I store this keto lemon loaf
A: Store leftovers in an airtight container at room temperature for up to 3 days. For longer freshness, you can refrigerate it for up to one week. The loaf tastes great chilled or at room temperature.
Q: What can I use instead of erythritol
A: While this recipe was tested with erythritol, you can typically substitute it with another granular keto-friendly sweetener like monk fruit or allulose in a 1:1 ratio. Be aware that this may slightly alter the final texture and taste.
Pro Tips
- Bring the eggs and sour cream to room temperature — the batter mixes smoothly and bakes into a more tender, even loaf.
- Coconut flour is extremely absorbent, so mix the batter only until just combined; extra stirring is what makes the loaf dry and dense.
- Poke small holes in the top of the warm loaf with a toothpick before pouring over the glaze so the tangy glaze seeps into the cake.
- This recipe is built specifically for coconut flour — it can't be swapped 1:1 with other flours without reworking the wet ingredients.
- Store the loaf in an airtight container at room temperature for up to 3 days or refrigerate it for up to a week; it's especially good chilled.
Frequently Asked Questions
Can I use a different flour instead of coconut flour?
Not as a 1:1 swap. Coconut flour's high absorbency means another flour would need significant adjustments to the wet ingredients to hit the right texture.
Why do my ingredients need to be at room temperature?
Room temperature eggs and sour cream emulsify into a smooth batter, which bakes up more tender and uniformly.
How do I store this keto lemon loaf?
Airtight at room temperature for up to 3 days, or in the refrigerator for up to a week. It tastes great both chilled and at room temperature.
What can I use instead of erythritol?
A granular keto-friendly sweetener like monk fruit or allulose works at a 1:1 ratio, though it may slightly change the final texture and taste.
Recipe card below.
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Keto Lemon Poppy Seed Loaf
Ingredients
Method
- Preheat your oven to 325°F / 165°C. Prepare a 9x5-inch loaf pan by lining it with parchment paper, leaving an overhang on the sides to act as handles for easy removal.
- In a medium bowl, whisk together the dry : coconut flour, granular erythritol, baking powder, xanthan gum, and salt to break up any clumps.
- In a separate large bowl, whisk the eggs until light and frothy.
- Add the sour cream, avocado oil, and vanilla extract, and whisk until the mixture is smooth and fully combined.
- Gradually pour the dry into the wet , stirring with a spatula until just combined.
- Do not overmix. Gently fold in the poppy seeds, lemon zest, and fresh lemon juice.
- Pour the batter into the prepared loaf pan and smooth the top with your spatula.
- Bake for 50-60 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean.
- While the loaf bakes, prepare the glaze.
- In a small bowl, whisk the heavy whipping cream and confectioners'-style erythritol until smooth and the sweetener has completely dissolved.
- Set aside.
- Remove the loaf from the oven and let it cool in the pan for 15 minutes.
- Pour the glaze evenly over the warm loaf. Allow the loaf to cool completely in the pan before using the parchment handles to lift it out, slice, and serve.
