Use a peeler or microplane to remove the zest from 4 lemons, taking only the fragrant yellow outer layer. Avoid the white pith completely, because it will make the lemonade bitter. Place the zest in a bowl with the sugar. Rub the zest into the sugar with your fingertips for 2–3 minutes until the sugar feels damp, deeply fragrant, and lightly yellow. This is the cold extraction step — the sugar pulls the aromatic oils out of the lemon peel without heat, which gives you a cleaner, fresher lemon flavor than boiling. Let the mixture sit for 20–30 minutes at room temperature. Rubbing rather than simply mixing the zest into the sugar is what actually ruptures the peel's tiny oil glands — that mechanical friction is what releases the aromatic oils into the sugar, a process heat alone would replicate differently, and often less cleanly.

Juice enough lemons to get 360ml fresh lemon juice. Strain out the seeds. A little natural pulp is fine. Pour the lemon juice into the bowl with the lemon-zest sugar and stir well for 1–2 minutes until most of the sugar has dissolved. The acid from the juice helps dissolve the sugar and carries the lemon oil into the base. If you want a cleaner-textured lemonade, strain out the zest at this stage, pressing firmly to extract all the fragrant syrup. If you prefer a slightly more rustic homemade style, you can leave a little fine zest in. The lemon juice's own acidity does real work here beyond simply adding tartness — it actively helps dissolve the sugar while also carrying the already-released lemon oils fully into the liquid base.

Cut the passion fruits in half and scoop out the pulp. Measure out 240ml. Keep the seeds — they are part of the classic look and texture. Do not blend the pulp aggressively. You want the seeds intact and suspended through the drink, not broken up, because crushed seeds can add bitterness. Passion fruit seeds carry a genuine bitterness within their own structure, similar to many fruit seeds — keeping them whole rather than blended or crushed is what keeps that bitterness contained rather than released into the finished drink.

In a large pitcher, combine the lemon-sugar base, the passion fruit pulp, the cold water, and the pinch of salt, if using. Stir thoroughly until fully combined. The lemonade should be bright golden-yellow, tart, aromatic, and tropical, with visible passion fruit seeds throughout. Taste and adjust if needed: if too tart, add 15–30g more sugar and stir until dissolved; if too intense, add another 100–150ml cold water; if you want stronger passion fruit flavor, add a little more pulp. This tasting checkpoint matters directly given how much passion fruit itself can vary batch to batch — building in a deliberate adjustment stage here accounts for that natural variability rather than assuming a fixed recipe will always land at the same balance.

Refrigerate the lemonade for at least 30 minutes before serving so the flavors settle and the drink becomes fully cold. That resting period lets the lemon oils, passion fruit, and sugar fully integrate together, rather than serving a drink where each component still tastes somewhat separate and undeveloped.

Fill 8 glasses with ice and pour over the chilled lemonade. Stir the pitcher before pouring each time so the passion fruit seeds stay evenly distributed. Garnish each glass with a halved passion fruit resting on the rim. Serve immediately. Restirring the pitcher before every single pour, rather than just once at the start, accounts for how quickly the denser passion fruit seeds naturally settle toward the bottom between pours — without that habit, later glasses would end up with noticeably fewer visible seeds than the first.