Purple Sweet Potato Sandwich Loaf
1714kcal
Ingredients
Sourdough Starter Levain (Night 1)
- 7 g Sourdough starter
- 35 g Water
- 35 g Bread flour
Main Dough (Day 2)
- 300 g Bread flour (100%)
- 120 g Roasted and mashed purple sweet potato (cooled completely)
- 125 g Water
- 1 Large Egg
- 30 g Sugar (10%)
- 60 g Active sourdough levain (20% – from stage above)
- 6 g Salt (2%)
- 30 g Softened or melted butter (10%)
- 0.5 g Dry yeast (optional, added with water to reduce sourness)
Equipment
- Stand Mixer (fitted with dough hook attachment)
- Standard Loaf Pan
- Parchment Paper (or butter for greasing pan)
Method
1. Night 1: Build Levain & Roast Potato (10:00 PM)
- In a small jar, whisk 7 g starter into 35 g water, then add 35 g bread flour. Cover loosely and let ferment at room temperature 74–78°F (23–26°C) for 8–10 hours until peak (at least triples).
- Roast purple sweet potato until fork-tender, cool completely, and mash thoroughly until smooth.
2. Day 2: Mixing & Cold Retard
- Autolyse (8:00 AM): In stand mixer bowl, combine 125 g water, 300 g bread flour, 120 g purple sweet potato mash, 1 large egg, 30 g sugar, 60 g active levain, and optional 0.5 g dry yeast. Cover and let autolyse for 1 hour.
- Mixing (9:00 AM): Knead on low speed for 2–3 minutes (or KitchenAid speed 3 for 3–4 minutes). Add 6 g salt and mix for 2 more minutes until a cohesive ball forms.
- Butter Incorporation: Add 30 g soft/melted butter, increase speed to medium, and knead for 10 minutes until smooth and passes the windowpane test.
- Bulk Proofing: Cover and proof for 3–4 hours at 76–80°F (24–28°C), performing 2 stretch-and-folds during this window until slightly puffy.
- Cold Retard (1:00 PM): Transfer dough container to refrigerator for 8–9 hours of cold fermentation.
3. Night 2: Shaping & Overnight Proof (10:00 PM)
- Remove dough from fridge. Roll into a smooth cylinder half the length of your loaf pan.
- Line bottom of loaf pan with parchment paper (or grease with butter and dust with flour). Place shaped roll into pan.
- Cover dough and let proof overnight at 72°F (22°C) for 7–9 hours until doubled or more in volume (rising past the pan rim by morning).
4. Day 3: Bake (7:00 AM)
- Preheat oven to 375°F (190°C).
- Bake loaf for 35–40 minutes until golden brown on top.
- Cool completely on a wire rack before slicing.
Nutrition
Calories1714kcalCarbohydrates299gProtein48gFat34gSaturated Fat18gPolyunsaturated Fat4gMonounsaturated Fat8gTrans Fat1gCholesterol228mgSodium2662mgPotassium813mgFiber12gSugar36gVitamin A18018IUVitamin C3mgCalcium125mgIron5mg
Notes
- The Starch Secret Behind Ultra-Soft Sandwich Loaves: Incorporating mashed potatoes into bread dough is an old-world baking secret for creating a cloud-like texture. Potatoes are packed with gelatinized starches that disrupt the wheat gluten network just enough to prevent the crumb from turning tough or rubbery. Furthermore, these starches hold onto moisture significantly longer than wheat flour alone, keeping your sandwich slices soft and fresh for days without stale staling.
- Why the Final Pan Rise Happens Overnight on the Counter: Enriched doughs packed with dense potato flesh, eggs, sugar, and butter ferment significantly slower than standard lean flour-and-water artisan loaves. Giving the shaped pan loaf a slow, 9-hour room temperature proof on your kitchen counter overnight allows the wild yeasts to work steadily over many hours, ensuring a gorgeous, towering oven spring by the time you wake up.
- Achieving an Ultra-Smooth Potato Mash: To avoid unappealing pockets of unmixed potato throughout your beautiful purple crumb, ensure your sweet potato is boiled until completely falling apart. Running the hot potato chunks through a fine mechanical potato ricer or a mesh sieve yields a silky, velvety paste that incorporates seamlessly into the milk and flour matrix during the autolyse stage.