Caffeine is a bitter compound present in coffee, which primarily affects your metabolism, particularly the central nervous system. Generally, the caffeine content of coffee is not harmful if you consume it in moderation -- no more than two to four cups per day. If you have a sensitivity to the substance, however, you may opt for the decaffeinated version, although the caffeine content may be more than you think. Whether you’re curious about the level of caffeine present in your coffee, or you need to measure it to safeguard your health, caffeine testing is a simple process you can do quickly and efficiently. You just need to have the proper testing strip.