Day 1: Place the clean jar on the digital kitchen scale and add 80 g (2.82 oz) all-purpose flour.

Day 1: Add 80 ml (2.71 fl oz) water to the flour in the jar.

Day 1: Mix the flour and water thoroughly with the spoon until no dry flour streaks remain.

Day 1: Cover the jar loosely and place it in a warm spot for 48 hours; an oven that is switched off may be used as a sheltered warm location.

Day 3: Discard approximately half of the starter from the jar, leaving about 80 g (2.82 oz) sourdough starter.

Day 3: Add 40 g (1.41 oz) all-purpose flour and 40 ml (1.35 fl oz) water to the remaining starter.

Day 3: Mix until smooth, then scrape and clean the inside sides of the jar with the rubber spatula.

Day 3: Cover the jar loosely and return it to a warm place for 24 hours.

Day 4: Discard approximately half of the starter, leaving about 80 g (2.82 oz) sourdough starter in the jar.

Day 4: Add 40 g (1.41 oz) all-purpose flour and 40 ml (1.35 fl oz) water to the jar.

Day 4: Stir the starter until fully combined, then clean the sides of the jar with the rubber spatula.

Day 4: Cover loosely and keep the jar in a warm place for a further 24 hours.

Day 5: Check that the starter is active, with visible bubbles and a tangy fermented aroma, before using it to make bread.

For storage: Keep the active starter in the refrigerator when it is not being used.

For maintenance: Every 14 to 21 days, retain 1 part sourdough starter and feed it with 2 parts all-purpose flour plus 2 parts water.

If a dark liquid layer forms on the starter, pour off the liquid and feed the starter using the 1:2:2 starter-to-flour-to-water ratio.