Place a paper filter in a pour-over dripper and rinse with hot water; discard the rinse water from the vessel.
Add 200 grams of ice cubes directly into the bottom of a heat-resistant carafe or glass.
Place the dripper onto the carafe and add 25 grams of medium-fine coffee grounds to the filter.
Initiate the bloom by pouring 50 grams of hot water over the grounds, ensuring all are saturated; wait 45 seconds.
Pour the remaining 200 grams of water in concentric circles, maintaining a steady flow to complete the brew within 3 to 4 minutes.
Remove the dripper once the liquid has finished draining through the coffee bed.
Swirl the carafe vigorously for 15 seconds to flash-chill the coffee concentrate against the melting ice.
Pour the resulting chilled coffee into a serving glass filled with fresh ice and add dairy or sweetener if desired.