Japanese iced coffee is the method of making iced coffee. I misunderstood and thought you were making cold brew.

For cold brew, you put coarsely ground coffee into cold water and let it brew in the fridge for 24+ hours. The water to coffee ratio is 8:1 *by weight.

By comparison, the typical ratio for making normal hot coffee is 15:1 (water:coffee) by weight.

For Japanese iced coffee you use the typical 15:1 ratio but you cut your water in half and use ‘half the water weight worth’ of ice.

So the ratio is 7.5 water: 1 coffee : 7.5 ice. Brew hot coffee with 7.5 parts water and 1 part coffee grounds over top of 7.5 parts ice.

Put the ice in the bottom of whatever receptacle you’re brewing into - ie the coffee pot, if you’re brewing with the machine.

When brewing is done, stir or swirl until all of the ice melts and then pour over a little more ice when you want to drink it.

In my experience, this tastes better than brewing normal hot coffee and putting it in the fridge.