Weigh the ground coffee and fill the empty tea bags. Once you get the hang of it, you can eyeball it.
Put the bags into a container and fill with 1 liter of water, store in the refrigerator for 8 hours, then it's done.
If you leave the bags in, the coffee will become bitter, so remove, then stir. Since the coffee in our home disappears quickly, I leave them in. Adjust the amount of coffee grounds to your liking.
Story Behind this Recipe
I always use a specialized cold-brew pot to make iced coffee, but I use this recipe when I'm making a large amount or when I'm at my parents' house. Making your own iced coffee is better for the environment, since you won't have to waste a plastic bottle. (With the specialized cold-brew pot, you don't even need tea bags!)
It takes 8 to 10 hours for tasty coffee, so I recommend setting it up before you go to bed, or before leaving your home in the morning. If you use only 1 empty tea bag, the coffee grinds may leak out. You may want to use the second bag to cover the first with the opening at the other end, strain the coffee through a strainer, or transfer it to another container through a tea strainer.