Of course iced coffee and cold brew have a very different taste profile but it can still get hot in the northern hemisphere so here it is:

• 86g coffee, coarsely ground (32 on my 1zpresso JX). Works great with store-bought beans, in my case Kaufland's medium roast Brazil beans (haven't tried it with specialty coffee, not sure if you're going to get your money's worth that way)
• 750g filtered water, room temperature or cold
• patience (I found that 16 hour brew works best but anywhere between 12 and 18 hours is fine)

I use a french press with the filter off. Mine is 1L hence the weird proportions, that's accounting for the coffee grounds volume too. What you get with this recipe is about 500ml of concentrate

• Add 2/3rds of the water and let bloom for 10 minutes then add the remaining water(500g->250g)
• Pop it in the fridge for at least 12 hours, 16 is best
• Filter with a metal filter. I just screw the French press filter, press to just about under the surface.
• Dilute with ice cold water for a refreshing drink or 92°C if you want it warm. I do a 1:1 ratio but that's up to personal taste.

Link to original Reddit comment from 3 years ago. Credit to /u/theboyinthemoon