Hjortronsylt

Step 1: Sterilise the jar and lid: wash in hot soapy water, rinse, then set the jar upside down in a 250°F oven for 10 minutes (or boil jar and lid for 10 minutes). Let it cool and dry completely; jar, lid and every spoon you use must be bone dry. Use four 250 ml jars and keep them warm in the oven.

Step 2: Pick over the 2 ¼ lb cloudberries, removing leaves and hulls; if frozen, let them thaw in a bowl to keep the juice.

Step 3: Put the berries and 3 ½ tbsp water in a wide pan over a medium heat and bring to a simmer, about 5 minutes, until the berries start to burst.

Step 4: Stir in the 1 ⅛ lb white sugar and simmer for 3–5 minutes, stirring gently, until the sugar has dissolved and the jam looks glossy and amber. Skim off any foam.

Step 5: Ladle into the hot jars. For fridge storage, close and cool; it keeps 2 months. Water-bath for room-temperature storage: fill the hot jars to 1 cm from the top, wipe the rims, close, stand them on a rack in a deep pan of water that covers them by 3 cm, bring to a rolling boil and boil for 10 minutes (add 1 minute per 300 m above sea level). Lift out and cool undisturbed; the lids should be pulled down. Any jar that does not seal goes in the fridge.

Step 6: Sealed jars keep a year in a cool, dark place; refrigerate after opening and use within 1 month, with a clean, dry spoon. Throw it away if you see mould, if it fizzes or smells of alcohol, or if a lid bulges or leaks.