"Half caf" is short for half caffeinated, referring to a cup of coffee with a 50/50 mix of decaf and regular coffee. Many people drink half caf because it reduces the amount of caffeine intake while still packing a punch. It also allows people to drink twice as many cups of coffee while getting close to the same amount of caffeine as half as many cups.

It is important to note however, that decaffeinated coffee still contains a small amount of caffeine. In general, about three percent caffeine remains regardless of the method of decaffeination. All else being equal, two cups of caffeinated coffee have less caffeine than four cups of half caf. In the latter case, the “extra” two cups of decaf add roughly six percent more caffeine to the two cups of regular coffee consumed.

Half caf is a nice compromise for those that prefer the taste of caffeinated coffee but are sensitive to caffeine. In most methods of decaffeination, flavor molecules are separated from the beans along with caffeine molecules. An agent is used to bind the caffeine in order to remove it, then the flavor molecules are returned to the beans through soaking. One method uses baths already saturated with flavor molecules to help preserve flavor in the beans. How the beans are decaffeinated can make a big difference in the coffee's taste.

It’s easy to make half caf at home. Just purchase two blends of your favorite coffee, one caffeinated and one decaf. Use a spoonful of each to brew a nice cup of half caf. You can also add flavor to the ground coffee prior to brewing. Try a few drops of vanilla extract for a sweet mellow flavor, or add a few sprinkles of cinnamon to reduce bitterness.

Quitting caffeine cold turkey can cause symptoms such as headache and fatigue while the body readjusts to the absence of the stimulant. If trying to eliminate caffeine entirely, half caf is a good first step. After drinking half caf for a few weeks, try mixing greater portions of decaf with regular coffee until you are drinking decaf only. At this point gradually reduce the number of cups consumed per day. Make the coffee weaker as you progress. By gently reducing your caffeine intake you should be able to avoid withdrawal symptoms.