The Keto Baking Mechanic™ — Recipe

Keto Sourdough Brioche Bagels

Where We Create, Tweak and Enhance
Keto and Low Carb Breads and Baked Goods

🥐 Full Deli-Size Shape, Brioche-Light Crumb, 2.23g Net Carbs per Serving

This is a new style of Keto sourdough bagel that combines the bagel shape and size, but with a light, pillowy, Brioche-style crumb on the inside. That combination — real size and real softness at the same time — is what vital wheat gluten makes possible, and it’s the whole idea behind this recipe.

A traditional deli bagel of this size runs 50g or more in carbs — before you even add a topping. This one gives you the full shape and the satisfying chew of the real thing at 4.46g net carbs per bagel — just 2.23g per serving (half a bagel), because the dough leans on vital wheat gluten, almond flour, and a Brioche-style enrichment instead of refined wheat flour.

https://sinlesssourdough.com/shop/

Why This Recipe Works

What Makes These Brioche Bagels Different?

Most keto bagel recipes solve the structure problem by going small and dense — a flattened, heavy puck that holds together because there isn’t much of it to hold. This recipe solves it a different way: it builds enough real structure into the dough that it can afford to be big and light at the same time.

Why Does This Recipe Work?

Qualities of the Main Ingredients

Vital Wheat Gluten

This is the backbone of the recipe — roughly 75–80% pure protein by weight. It’s what gives this dough enough strength to hold a full, large bagel shape through shaping, proofing, and baking without collapsing or going dense in the centre.

Almond Flour and Coconut Flour

Sifted together, these soften the crumb so the bagel doesn’t eat like pure gluten. Coconut flour is very absorbent, which is one reason the milk amount can vary from batch to batch.

Biome Boss™ Living Starter

Your living sourdough starter or discard adds tang and supports fermentation. Its moisture level varies, so it directly affects how much milk the dough needs — always start with 1 cup of milk and add more only if needed.

Whole Psyllium Husks

Whole psyllium husks (not powder) absorb moisture and form a gel that binds the crumb together, which matters even more in a larger bagel — it helps keep the centre from crumbling once you’ve got more dough to support.

Ingredients

Wet Ingredients

• 1 cup Fairlife 2% milk, warmed (240 mL), plus more if needed (or almond or coconut milk)*
• 1 tbsp instant yeast (10–11 g)
• 1 tsp sugar (4 g)
• 3 large eggs
• 1 cup Biome Boss™ Living Starter (240 g)
• ¼ cup unsalted butter, softened (57 g)
• ¼ cup cream cheese, softened (60 g)

*Always start with 1 cup of milk, then add more only if needed. The amount required depends on the moisture of your discard.

Dry Ingredients

• 1 cup almond flour + 2 tbsp coconut flour, sifted together (110 g + 16 g)
• 2 cups + 2 tbsp vital wheat gluten (250 g)
• 3 tbsp whole psyllium husks
• 1 tbsp double-acting baking powder (12 g)
• 1 tsp healthy salt (6 g)
• 2 tsp xanthan gum (optional and not mentioned in the video) — keeps the bagels from deflating

Egg Wash

• 1 egg yolk
• 2 tbsp Fairlife 2% milk (30 mL)

Equipment

• Stand mixer with beater attachment (strongly recommended — this dough is stiff)
• Kitchen scale (for dividing the dough evenly)
• Sifter or fine-mesh sieve
• Tea towel
• Cookie sheet lined with parchment
• Instant-read thermometer
• Aluminum foil (for tenting)
• Wire cooling rack

How Do You Make Perfect Keto Brioche Bagels?

Phase 1: Combine Milk, Yeast, and Sugar

Pour 1 cup of warm Fairlife 2% milk into the stand mixer bowl. Add the instant yeast and sugar, stirring briefly to dissolve.

Phase 2: Add the Remaining Wet Ingredients

Add the eggs and mix lightly. Then add the Biome Boss™ Living Starter, softened butter, and softened cream cheese. Mix on low speed for 10–15 seconds, just until loosely combined.

Phase 3: Add the Dry Ingredients and Check Moisture

Sift the almond flour and coconut flour together. Add the vital wheat gluten, the sifted almond-coconut flour mixture, whole psyllium husks, baking powder, salt, and xanthan gum (if using) on top of the wet ingredients. Mix on low speed with the beater attachment for about 2 minutes, until a shaggy dough forms.

Check the moisture of the dough. If it’s too dry, add more milk 1 tbsp at a time until the dough is sticky but holds together. It needs to be dough, not batter.

Phase 4: Rest (Autolyse)

Cover the bowl with a tea towel and let it rest for exactly 30 minutes at room temperature. The vital wheat gluten will tighten, the psyllium will form a gel, and the dough will become firmer and smoother.

Phase 5: Knead / Windowpane Test

Knead on medium-low speed for about 5 minutes. If the dough is too wet, mix in 1–2 tbsp whole psyllium husks, then remove the bowl and let the dough stiffen in the refrigerator for about 15 minutes. If it’s too dry, add milk 1 tbsp at a time until the dough pulls together. Knead for about 8 minutes more, until the dough is smooth, elastic, and slightly tacky (not sticky).

Perform the windowpane test: stretch a small piece of dough — it should form a thin, translucent membrane without tearing. If it’s too soft, add another 1 tbsp psyllium. If it’s too firm, add 1–2 tsp warm milk.

Phase 6: Shape the Bagels

Divide the dough into 2 equal portions (use a kitchen scale for precision). Roll each portion into a tight ball by tucking the edges underneath and rolling in circular motions. Divide each portion into 6 balls, for 12 in total.

Stretch and fold each ball at least 4 or 5 times to create tension on top of the dough. Flatten the ball on your work surface into a disk, then push your thumb through the centre to create the bagel hole. Mould the dough with your hands so the ring is the same width all the way around. Repeat for all 12 pieces and set each bagel on the parchment-lined cookie sheet.

Phase 7: Second Proof

Proof for 30 to 60 minutes, until the dough expands. Preheat the oven to 350°F (180°C) while the dough finishes proofing.

Phase 8: Glaze and Bake

Brush the tops with egg wash for that signature golden sheen, and sprinkle with your favourite seasonings.

Bake for 25 to 30 minutes, until the tops are light golden and the internal temperature reads 190–200°F (90–94°C). Tent with foil if they’re browning too quickly after 20 minutes — watch closely, as they brown quickly.

Turn off the oven and leave the bagels inside for 5 to 10 minutes. This keeps them from deflating too much.

Phase 9: Cool Completely

Remove the bagels from the oven and cool them on the cookie sheet for 10 minutes to set the structure. Transfer to a wire rack and cool completely for 2 hours before slicing — this prevents a gummy texture.

Troubleshooting

Variations

• Everything Bagel: Top with everything bagel seasoning before baking
• Cinnamon Raisin: Add 1 tsp cinnamon to the dry mix and fold in 2 tbsp chopped raisins
• Jalapeño Cheddar: Fold in ½ cup shredded sharp cheddar and 1 diced jalapeño
• Blueberry: Fold in ⅓ cup fresh blueberries (adjust bake time slightly for extra moisture)
• Asiago Herb: Top with grated asiago and dried Italian herbs before baking
• Chocolate Chip: Fold in ⅓ cup sugar-free chocolate chips

Variations add their own carbs and calories — the nutrition facts below are for the plain bagel.

Nutrition Facts

Note: all nutritional values are estimates only. Actual values vary with ingredient brands, product formulations, measuring methods, and nutritional standards in different countries. Using Fairlife Skim instead of 2% saves about 49 kcal and 4.7g fat for the whole recipe; Fairlife 3.25% whole milk adds about 38 kcal and 3.6g fat. Carbs and net carbs stay the same. Replacing Fairlife with almond, coconut, or another milk will change the totals, so recalculate using your own ingredients. If you shape the dough into fewer, larger bagels, the per-bagel numbers will be higher.

Why these macros fit a flexible keto lifestyle: a high protein-to-carb ratio, meaningful fibre, and a net carb count low enough to fit most daily targets even at this full, satisfying size.

Serving Ideas

• Classic deli-style: cream cheese, smoked salmon, red onion, capers
• Breakfast sandwich: fried egg, cheddar, bacon
• Toasted and buttered: simple, warm, and satisfying on its own
• Open-faced melt: turkey, swiss, and a quick broil

Storage

Room Temperature: Up to 2 days in an airtight container.

Fridge: Up to 1 week, well wrapped.

Freezer: Up to 3 months. Slice before freezing so you can toast individual halves straight from frozen.

Why Is Your First Bake a Practice Bake?

Oven Variations: Every oven runs a little hot or cool. A large bagel needs even heat all the way through, so your first batch tells you whether your oven needs a few extra minutes or earlier tenting with foil.

Ingredient Brand Differences: Vital wheat gluten, coconut flour, and psyllium husks absorb liquid differently between brands, and starter moisture varies too. Your first bake shows you whether your dough needs a touch more or less milk next time.

Personal Palate Adjustments: Some bakers want more tang (let the starter ferment longer), some want it milder (use a freshly fed starter). Adjust to taste on your second batch.