CoffeeSock® Original Glass Ring DIY ColdBrew Coffee Kit. Make your own Cold Brew at home using this sustainable and simple solution! With easy instructions on the jar, you'll effortlessly master home cold brewing. For best results we recommend our Costa Rica Llano Bonito for drinking black, or our Cold Brew Blend when adding creamer (great black too!), or experiment with our other coffees! And, for something completely different, try cold brewing our Cascara ; a naturally sweet, antioxidant rich, mildly caffeinated tea made from the cherry (fruit) of the coffee tree!