In a large jar or pitcher, add 1 cup coarsely ground coffee. Pour 4 cups cold filtered water over the grounds to fully saturate them. Stir gently to ensure all grounds are wet and distributed.

Steep

Cover the container and let steep in the refrigerator or at room temperature for 12 to 18 hours. Longer steep (up to 18 hours) yields stronger concentrate; around 12–14 hours is balanced.

Strain

After steeping, strain the mixture through a fine mesh sieve lined with cheesecloth or a coffee filter into a clean container. If needed, strain a second time to remove remaining fines. You now have roughly 1 to 1.25 cups of cold brew concentrate (adjust amount if yield varies).

Store

Cover and refrigerate the concentrate for up to 1 week. Use chilled for best results.

Assembly

Prepare glass

Fill a tall glass with 1 cup ice cubes.

Dilute

Pour 1 cup cold brew concentrate into the glass over the ice. Add 1 cup cold water or milk (for creamier texture) to dilute to drinking strength (about 1:1 concentrate to liquid). Adjust ratio to taste if you prefer stronger or weaker coffee.

Sweeten

Stir in 2 tablespoons simple syrup (or other sweetener) while cold so it dissolves evenly. If using granulated sugar, dissolve first in a small amount of warm water to make syrup. Taste and adjust sweetness.

Finish

Add 2 tablespoons milk, cream, or dairy-free alternative if you want a creamier iced coffee. Gently stir to combine.

Optional Finishes

Flavoring

For a flavored iced coffee, add 1/4 teaspoon vanilla extract and/or a pinch (1/8 tsp) ground cinnamon to the glass and stir.

Garnish

Top with 2 tablespoons whipped cream if desired and a light dusting of cinnamon. Serve immediately with a straw.