Borș

Step 1: Wash a 5 litre glass jar or ceramic crock, a long wooden spoon and a lid or plate in very hot soapy water, rinse well, then scald all of them with boiling water and leave to air-dry upside down.

Step 2: Bring the 12 ½ cups water to the boil and leave it to cool for 10 minutes, to about 176°F.

Step 3: Put the 1 ⅛ lb wheat bran and 3 ½ oz fine cornmeal in the jar and stir in about 500 ml of the hot water to make a smooth, thick paste with no dry lumps.

Step 4: Pour in the rest of the hot water, stirring, then leave until it feels just warm to a clean finger, about 35–104°F.

Step 5: Stir in the 2 tbsp active sourdough starter (or crumble in the bread), add the 3 sprigs lovage and the 4 sour cherry leaves if using. Cover the jar with a clean cloth and a loose lid.

Step 6: Leave at room temperature (20–75°F), away from direct sun, for 3–4 days. Stir once a day with the clean wooden spoon; after 24 hours you should see fine bubbles and smell something like tangy bread.

Step 7: Taste a spoonful from day 3: it is ready when it is clearly sour, pale yellow and cloudy. Throw the whole batch away if you see fuzzy or coloured mould, pink streaks or a rotten smell.

Step 8: Strain through a sieve lined with a clean cloth, pressing the bran gently. Pour the borș into clean bottles and refrigerate for up to 2 weeks.

Step 9: To use, heat the borș to the boil separately and add it to your soup at the end, then simmer together for at least 2 minutes; never use it raw. Spread a few spoonfuls of the drained bran on a tray to dry completely and keep it in a jar as starter for next time.