Sourdough Discard Irish Soda Bread – Crust & Crumb Academy

Recipe Pantry • Sourdough Discard

Sourdough Discard Irish Soda Bread

⏱

Prep

10 min

🔥

Bake

40-45 min

⏳

Total

55 min

🍞

Yield

1 loaf

💧

Hydration

75%

📊

Level

Beginner

Your discard deserves better than the trash. Irish soda bread upgraded with sourdough discard — richer flavor, same quick bake. No rise time, no fuss.

Ingredients

The Dough

Metric	Volume	Ingredient
250g	2 cups	All-purpose flour
100g	¾ cup	Whole wheat flour
150g	½ cup + 2 tbsp	Sourdough discard (100% hydration, unfed)
120g	½ cup	Cold buttermilk
6g	1 tsp	Baking soda
6g	1 tsp	Fine sea salt

Optional Add-Ins

Metric	Volume	Ingredient
8g	1 tbsp	Caraway seeds
80g	½ cup	Raisins or currants

Process

Combine dry ingredients

Whisk together all-purpose flour, whole wheat flour, baking soda, and salt. Add caraway or raisins if using.

Add the discard

Add the sourdough discard to the bowl. Use a fork to break it up and distribute through the flour. It'll look crumbly and messy — that's fine.

Add buttermilk and bring together

Pour in cold buttermilk and mix with a fork or your hand just until a rough dough comes together. Sticky and shaggy is right. Don't smooth it out.

Shape into a round

Flour your hands lightly. Turn dough out and gently form into a round ball, tucking edges underneath. Press to about 3 inches tall.

Score the cross

Using a sharp knife, cut a deep cross (½ inch deep) across the top, extending nearly to the edges. This lets the bread expand and the center cook through.

Preheat to 425°F (220°C) 30 min

Preheat oven with your Dutch oven or cast iron inside. Hot vessel = better bottom crust.

Transfer and bake (first stage) 20 min

Lower the loaf on parchment into the hot vessel. Bake at 425°F (220°C) for 20 minutes.

Reduce heat and finish 18-22 min

Lower to 400°F (205°C) and bake 18-22 more minutes. Watch the color — discard versions can go dark faster than the classic.

Check doneness

Tap the bottom — hollow means done. Internal temperature should reach 195-200°F (90-93°C).

Cool on a wire rack 30 min

Move to a wire rack immediately. Wait at least 30 minutes — the discard version has more moisture and needs the full rest to set the crumb.

🧪 What the Discard Actually Does

Sourdough discard contains lactic and acetic acids from fermentation. Those acids interact with baking soda like buttermilk does — but they also bring a complex fermented flavor that plain buttermilk can't replicate. You need both: the discard for flavor, the buttermilk for the chemical reaction to fully kick off.

Baker's Percentages

All-purpose flour

71.4%

Whole wheat flour

28.6%

Sourdough discard

42.9%

Buttermilk

34.3%

Baking soda

1.7%

Salt

1.7%

📐 Learn How Baker's % Works →

Henry's Tip

Discard dough is stickier than the classic version. Flour your hands, not the dough. If your discard is cold from the fridge, that's fine — and actually preferred. Older discard (3-5 days) gives more complex flavor.

Storage

🏠 Room temp: Best the day it's baked. Wrap in cloth or paper bag for up to 2 days.

❄️ Frozen: Slice first, wrap tightly, freeze up to 4 weeks. Toast from frozen.

🔄 Refresh: Toast slices or warm at 350°F (175°C) for 8-10 minutes.

Classroom Lessons

🎓 Crust & Crumb Academy

📖

Crust & Crumb GlossaryEvery underlined term links here

📐

Learn How Baker's % WorksBaker's Percentage · Module 4

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