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A banana loaf with a paler crust than usual, cut to show a dense set crumb speckled with banana.

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Banana bread (no added sugar)

A naturally sweetened sourdough discard banana bread with zero added sugar. Sweetness comes entirely from very ripe bananas, the riper and blacker the better. The sourdough discard adds tang and depth that keeps the loaf from tasting flat without sugar. Moist, tender, and genuinely satisfying. Works for breakfast or a lunchbox, as a toddler snack, or as an everyday loaf for anyone reducing refined sugar.

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Ingredients

Makes 1 loaf

  • Very ripe bananas (mashed)4 bananas (approx. 400g)
  • Sourdough discard150g
  • Plain flour200g
  • Unsalted butter (melted)90g
  • Eggs (large)2 eggs
  • Vanilla extract1 tsp (5g)
  • Bicarbonate of soda (baking soda)1¼ tsp (7g)
  • Fine sea salt¾ tsp (4g)
  • 900g (2lb) loaf tin
  • Large mixing bowl
  • Kitchen scale
  • Whisk
  • Rubber spatula
  • Skewer or toothpick
  • Wire cooling rack
  • Bread knife, serrated
Alternatives, sizes and where to buy

Method

  1. 1

    Preheat the oven

    5 min

    Set your oven to 175°C (155°C fan) / 350°F. While it heats, grease a loaf tin generously with butter, or line it with parchment.

  2. 2

    Prep the bananas

    5 min

    Peel your bananas. The skins must be fully black. If any yellow remains, bake them unpeeled on a tray at 175°C (155°C fan) / 350°F for 15–20 minutes until completely black, then let them cool. Mash them well with a fork in a large mixing bowl. You need about 400g mashed banana, roughly 4 large bananas. This recipe only works with the ripest bananas you can find.

  3. 3

    Mix wet ingredients

    5 min

    To the bowl of mashed bananas add: 90g melted butter (cooled slightly), 2 eggs, 1 tsp (5g) vanilla extract, and 150g sourdough discard. Whisk until fully combined, about 1 minute. The batter will look pale and not very sweet. This is correct: the banana provides all the colour and sweetness.

  4. 4

    Add dry ingredients and fold

    5 min

    Sprinkle directly over the wet batter: 200g plain flour, 1¼ tsp (7g) bicarbonate of soda (baking soda), and ¾ tsp (4g) fine sea salt. Using a spatula, fold gently until just combined. Stop the moment no dry flour streaks are visible. Pour batter into prepared tin and smooth the top. The batter will be quite liquid, from all the banana and the absence of sugar. This is correct, so don't worry.

  5. 5

    Bake

    65 min

    Place the tin on the centre rack at 175°C (155°C fan) / 350°F and bake for 60–70 minutes: without sugar the inside takes longer to set. At 45 minutes, cover loosely with foil so the top does not brown before the middle is cooked. At 60 minutes, push a skewer into the very centre. It should come out clean or with a few moist crumbs. If it is wet, bake for another 5–10 minutes.

  6. 6

    Cool and serve

    45 min

    Remove from oven. Leave in the tin for 15 minutes, because the no-sugar crumb is fragile when hot. After 15 minutes, turn out onto a wire rack. Wait at least 30 more minutes before slicing. The no-sugar crumb sets slowly and slicing too early produces a gummy, sticky texture. Fully cooled is strongly recommended: this loaf is noticeably better once completely cool.

Keeping it

  • Up to 3 days on the counterTightly wrapped, or in an airtight container. It is best from day 2.
  • Up to 3 months in the freezerSlice first, then wrap in cling film.
  • Warm it upToast slices from frozen, or 15–20 seconds in the microwave.

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