Keurig brewed. For use in Keurig brewing systems. For three generations, the Bigelow family has specialized in creating deliciously different, world class teas. To make English Breakfast Tea, we use fine quality tea from high elevated gardens, gently processed to bring out the tea's smooth, robust flavour. - Eunice & David Bigelow. 100% black tea packed in K-Cup portion packs. Caffeine Meter (represents average caffeine content; individual products may vary): Coffee: 100-120 mg. Black Tea: 30-60 mg. Green Tea: 25-50 mg. Decaf Tea: 1-8 mg. Herb Tea: 0 mg.