Pour the ground coffee into the bottom of the glass jar or container.
Add the water (you may not need all of it).
Put the lid on the bottle and give it a good shake so that the coffee and water are well combined. Place in the refrigerator for at least 8 hours, or up to 24 hours. The longer you steep the coffee, the stronger the concentrate will be.
Strain the coffee concentrate through a wire mesh strainer into a clean glass container. Press on the coffee grounds to extract the flavor, and compost or discard.
Tap the grounds out of the strainer and rinse it clean. Place a paper coffee filter inside the strainer, and pour the concentrate through the filter. Double straining it will make it nice and clear, with pure coffee flavor.
Store the concentrate in a tightly sealed glass bottle or container in the refrigerator for up to 2 weeks.
To make iced coffee, fill a glass with ice cubes and pour the coffee concentrate over. You can also add your favorite creamer, half and half, sweetened condensed milk, chocolate milk, sugar or flavored syrups if you like. Makes about 8 cups of liquid coffee concentrate.
Notes
You can easily double this recipe to make more concentrate. We recommend using it within 2 weeks for the best flavor.For a stronger coffee flavor, let the coffee grounds steep in the water for up to 24 hours in the refrigerator.