Heat 1 litre of water to 90–95°C. Add 8 or 9 black tea bags. Steep for exactly 3 minutes. Remove all bags simultaneously without squeezing. The same temperature and timing principles from the Lemon Iced Tea and Peach Iced Tea crowd preparations apply here — 90–95°C for 3 minutes produces the desirable warm, structured tea character ahead of the harsh tannin fraction. The specific note about 9 bags in 500ml applies here as in the peach preparation: the concentration calibration is 8–9 bags in 1 litre, producing an extract that is stronger than drinking-strength but not bitterly over-extracted, specifically designed to remain vivid at crowd scale after 1.8–2.2L of diluting water is added.

Stir 100g of light brown sugar into the hot tea immediately after bag removal until completely dissolved. The lower sugar quantity compared to the Lemon Iced Tea Pitcher (140–180g) reflects raspberry's own natural sweetness contributing to the perceived sweetness of the finished pitcher — the same quantity of added sugar at raspberry's natural fructose contribution produces a specifically sweeter result than at lemon's very low natural sugar.

Allow the sweetened tea to cool for 5 minutes. Add the 300g of raspberries and the lemon zest simultaneously. The raspberry handling requires specific care: using a fork or the back of a spoon, gently crack each berry once — applying sufficient pressure to split the skin and release the vivid juice and aromatic compounds from the outer flesh without crushing the berry into a paste and without applying pressure to the seeds. Cracked berries release their pleasant volatile ester aromatic compounds — particularly α-ionone and various furanones — into the warm tea medium; crushed berry paste with broken seeds releases seed tannins simultaneously. The lemon zest's role alongside the raspberries is the same aromatic bridge function as in the Peach Iced Tea Pitcher — the citrus peel's volatile oil compounds in the warm tea providing a specifically clean, bright bridge between the tea's tannin warmth and the raspberry's vivid, bright fruitiness. Cover and steep for 8–10 minutes. At this temperature range (approximately 70–80°C at 5 minutes post-brew, cooling progressively through the 8–10 minute steep), the raspberry's pleasant aromatic compounds and vivid anthocyanin pigments extract into the warm tea. The cooling temperature through the steep period means the later minutes of the infusion are at a lower temperature than the initial minutes — this progressive cooling is specifically beneficial, capturing the volatile ester fraction efficiently in the first minutes while the temperature moderates the jam-adjacent cooked character that sustained high heat would develop.

Strain through a fine-mesh sieve, pressing gently but firmly on the combined raspberry and lemon zest solids. The raspberry seeds are the specific quality concern: press until the raspberry mass has yielded its vivid, flavoured liquid — stop before the seeds begin pushing through the mesh with resistance. The correctly strained extract should be completely seed-free, vivid raspberry-red, and specifically clear-looking despite its vivid colour. Do not leave any seeds in the strained extract. Unlike the mild tannin contribution of small amounts of raspberry seed material pressed through a sieve in small-batch preparations, 300g of raspberry seeds at crowd scale that continue extracting into the pitcher after straining produce a specifically detectable bitter note that develops over the refrigerator rest period. Always ensure complete removal. Allow to cool completely.

Pour the cooled raspberry tea extract into the large pitcher. Add 1.8 litres of ice-cold water. Stir gently. Taste with the raspberry-iced-tea crowd assessment: the tea should be the structural primary impression — warm, amber, specifically tea-character — with raspberry's vivid, bright, slightly tart-fruity aromatic clearly layered over it. The raspberry in correctly made raspberry iced tea is a specifically different aromatic register from the same raspberry in lemonade: where raspberry lemonade has the citric acid's bright sharpness as the structural backdrop for the berry, raspberry iced tea has the black tea's tannin warmth — producing a specifically more complex, more specifically interesting result. Add the optional lemon juice (30–60ml) only if the combined raspberry-tea character tastes flat despite the raspberry's natural tartness — mild, out-of-season, or lower-quality raspberries specifically benefit from the additional acid lift; vivid, fresh, peak-season raspberries typically do not require it.

Cover and refrigerate for 1–2 hours. Stir once before the first pour. Garnish each glass with 2–3 fresh raspberries resting on the ice and an optional lemon peel twist at the rim. Serve cold.