Add the coarsely ground coffee and loose jasmine green tea to a 32 oz wide-mouth mason jar.

Pour 960 ml of cold filtered water over the grounds and tea. Stir gently once with a long spoon to wet everything, then stop - no further agitation.

Seal the jar with its lid and place it in the refrigerator. Steep for 12 to 14 hours. Do not go beyond 14 hours or the tea becomes tannic.

After steeping, the liquid should be deep amber and the jasmine aroma should come through clearly when you open the lid.

Set a fine-mesh sieve over a large measuring cup or bowl. Line the sieve with a paper coffee filter or two layers of cheesecloth.

Pour the cold brew slowly through the lined sieve. Let it drain without pressing down on the grounds - pressing forces fine particles through and clouds the concentrate.

If visible sediment remains in the cup, strain once more through a fresh paper filter. Transfer the clear concentrate to a clean sealed jar and refrigerate.

Fill a glass with ice. Pour 120 ml (about 1/2 cup) of concentrate over the ice.

Add 120 ml of cold filtered water, oat milk, or whole milk to dilute 1:1. Adjust the ratio to taste - more concentrate for stronger coffee flavor, more water for a lighter drink.

Add a drizzle of honey or simple syrup if desired. Serve immediately.