Prepare the apples: Peel, core, and roughly chop all the apples into 2-3 cm chunks. You should have about 2 kg of prepared apple pieces. As you work, place the chopped apples in a large bowl with the lemon juice and toss gently – this prevents them from browning and adds a bright note to the final flavour. The apples will look pale and fresh, with a slight citrusy scent.

Start the cooking process: Place the chopped apples in a large, heavy-bottomed pot or Dutch oven. Pour in the apple juice or cider. Bring the mixture to a boil over medium-high heat – you'll see bubbles breaking the surface and hear a lively bubbling sound. Reduce the heat to medium-low, cover the pot, and let it simmer for 20-25 minutes. The apples will soften and become tender, easily pierced with a fork, and the liquid will take on a pale golden hue.

Blend until smooth: Remove the pot from the heat. Using an immersion blender (or carefully transferring the mixture to a countertop blender in batches), purée the cooked apples until completely smooth. The mixture will be a thick, pale beige sauce with a very fine texture – no lumps should remain. If using a countertop blender, allow steam to escape by removing the centre cap from the lid and covering with a tea towel.

Add the sugars and spices: Return the apple purée to the pot if you used a countertop blender. Stir in the brown sugar, granulated sugar, ground cinnamon, ground nutmeg, ground cloves, and salt. Whisk everything together thoroughly – you'll see the colour shift to a warm, golden brown as the sugars dissolve. The aroma at this point is absolutely intoxicating, with the spices mingling beautifully with the apple scent.

Slow simmer to perfection: Place the pot back over the lowest possible heat. Cook the apple butter uncovered for 1½ to 2 hours, stirring every 10-15 minutes with a wooden spoon. This is the most important step. The mixture will bubble gently – you should see small, lazy bubbles breaking the surface, not a vigorous boil. As it cooks, the apple butter will darken to a rich, deep amber colour and thicken considerably. You'll notice the spoon leaves a trail through the mixture that slowly fills in. When it's ready, a small spoonful placed on a chilled plate should hold its shape without any watery liquid seeping out around the edges.

Finish and store: Remove the pot from the heat and stir in the vanilla extract. The apple butter will look glossy and smooth, with a deep, almost mahogany colour. The fragrance will be intensely sweet and spiced. Let it cool completely in the pot – as it cools, it will thicken further. Transfer to sterilised jars or an airtight container and store in the refrigerator for up to three weeks, or freeze for up to six months.