Combine the cold brew concentrate and water in a large container or pitcher if making a batch. Start with 2 cups of water. After mixing in the condensed milk, if the coffee is still too strong for your liking mix in 1 additional cup at a time until it suits your tastes. If making just one serving, prepare it right in your drinking glass.
Whisk in the sweetened condensed milk until completely combined. Serve over ice or just chilled straight from the fridge.
If making a batch, transfer the coffee to an air tight container and keep in the fridge for up 7 to 10 days.
You can make your own cold brew concentrate or buy it at the store. To make your own you'll need 12 ounces of coffee beans, 12 cups of water, and brew the two together in the fridge for 12 to 14 hours. Make sure your beans are a course grind. Strain the coffee through a fine cheesecloth strainer before using it.
Love the idea of nitro cold brew coffee but need a little milk and sweet to it? Try making your own nitro version of Vietnamese cold brew coffee at home!