The strawberry quality determines the lemonade's quality more directly than any other decision in this preparation. Ripe, fragrant, deeply red strawberries — where the flesh is red throughout rather than white at the centre — produce a vivid, intensely flavoured syrup. Under-ripe, white-centred, or flavourless commercial strawberries produce a pale, mildly flavoured syrup regardless of technique. The most vivid, most fragrant, smallest strawberries are generally the most intensely flavoured; large, water-heavy strawberries bred for visual appearance often have significantly less flavour per gram. Hull and roughly chop — the pieces can be large as the cooking and blending will break them down completely.

Combine the 130g of white sugar, 240ml of water, and all the chopped strawberries in a medium saucepan. Place over medium heat and bring to a gentle simmer, stirring to begin dissolving the sugar. Cook for 5–8 minutes — shorter than the 10–12 minutes applied to peach — stirring occasionally and pressing the softening strawberries lightly against the pan's surface to encourage juice release. The strawberries should be completely soft and their juice fully released into the surrounding sugar-water medium by the end of the cooking period; the liquid should be a vivid, deeply ruby red. The 5–8 minute window is specifically calibrated for strawberry. Strawberry's volatile aromatic compounds — particularly the various furanones and esters responsible for fresh strawberry's characteristic sweet, fruity character — evaporate at a meaningful rate above 70°C during sustained cooking. At 5–8 minutes of gentle simmering, the strawberries release their juice completely and concentrate their flavour meaningfully without shifting significantly into the cooked, jam-like register that extended cooking produces. The visual indicator of the correct end point: the liquid should be vivid ruby-red and the strawberries should have fully collapsed without the surrounding liquid having reduced to a thick, syrupy consistency. If the liquid is reducing noticeably, reduce the heat and add a small splash of water.

Remove the saucepan from the heat immediately at the 5–8 minute mark. Stir in the 1 tsp of fresh lemon zest — the yellow part only, with no white pith. The lemon zest is added specifically off heat and infused in the warm strawberry syrup rather than during the cooking period or in the cold combined base. This timing allows the zest's fat-soluble limonene and terpene aromatic compounds to release into the warm syrup — integrating with the strawberry's own aromatic character during the infusion — while avoiding the bitterness that cooking the zest at sustained simmering temperature can develop from the pith's compounds. Allow the mixture to infuse covered for 5–10 minutes with the zest in the warm syrup.

After the 5–10 minute zest infusion, transfer the cooled mixture to a blender. Blend briefly at medium speed — 20–30 seconds — until mostly smooth. Strain through a fine-mesh sieve into a clean pitcher, pressing firmly on the blended solids to extract the maximum vivid ruby syrup. Press firmly — the cooked strawberry and blended mixture yields its juice efficiently under pressing; dry solids after pressing indicate maximum extraction. Discard the strained solids. Allow the syrup to cool completely.

In a large pitcher, combine the cooled strawberry syrup, 240ml of fresh lemon juice, 900ml of ice-cold water, and the pinch of fine sea salt. The salt is present at approximately ⅛ tsp in the full volume — sub-threshold for saltiness but specifically effective at brightening the strawberry's sweetness and sharpening the lemon's acidity into something more vivid. Stir thoroughly and taste. Adjust as needed: more lemon juice up to 300ml total for additional brightness; more cold water up to 1.2 litres for a lighter drink; additional sweetness via simple syrup if the strawberries were under-ripe.

Refrigerate for 1–2 hours until completely cold. Fill glasses with ice. Pour the chilled strawberry lemonade over the ice. Garnish with a lemon slice and sliced fresh strawberries. Serve immediately.