Put the raspberries and sugar into a medium saucepan. Gently mash the berries with the back of a fork until they look like a chunky, dark red jam — you want some whole bits remaining for texture later. The smell at this point is incredible, sharp and sweet all at once.

Pour the boiling water over the raspberry mixture and stir until the sugar has completely dissolved. You should see the liquid turn a vibrant, jewel-like red. Add the tea bags and push them under the surface with your spoon. Let them steep for exactly 5 minutes — any longer and the tea turns bitter, any shorter and it’s too weak.

After 5 minutes, lift out the tea bags and squeeze them gently against the side of the pan to release the last drops. Discard the bags. The liquid will now be a deep, glossy burgundy colour and smell richly of berries.

Set a fine-mesh sieve over a large heatproof jug or bowl. Pour the raspberry tea mixture through the sieve, pressing down on the solids with the back of a spoon to extract every last bit of syrupy goodness. You’ll be left with a smooth, clear-ish liquid with a gorgeous rosy hue. Discard the seeds and pulp.

Stir in the lemon juice and the litre of cold water. Taste it now — it should be refreshingly tart and sweet, not cloying. If it’s too strong for your liking, add a splash more cold water. The colour will lighten slightly to a soft rose pink.

Transfer the jug to the fridge and chill for at least 30 minutes, or until completely cold. I often make this in the morning and let it sit all day. When you pour it over ice, you should hear that satisfying clink of cubes hitting the glass.

To serve, fill tall glasses with ice cubes, pour over the chilled raspberry tea, and garnish with a mint sprig and a slice of lemon if you like. The mint adds a cool, fresh finish that lifts the whole drink.