Although merlot and cabernet are both types of red wine, they are actually made from different types of grapes. The chief difference between merlot and cabernet are their taste profiles: Merlot is smoother and more palatable to the novice wine drinker, while drier, more acidic Cabernet has a stronger, more robust flavor.
The merlot grape comes from the Bordeaux region of France. It ripens early; therefore merlot may be consumed "young," without going through an aging process. Merlot is typically smooth, medium-bodied, with bright fruit flavors like blueberries, cherries and blackberries. Its soft and subtle flavorings make merlot compatible with a wide variety of foods, including red meat, pasta, salad and seafood.
Cabernet sauvignon, by contrast, is boldly flavored and distinct. Cabernet sauvignon grapes also originated in France's Bordeaux region, but they are stronger flavored and more suitable for aging. Cabernet sauvignon is ideally aged in oak barrels for 5 to 10 years before consuming. Its flavor profile is in stark contrast to merlot's, boasting vanilla, warm spice, tobacco and even leather flavors and aromas. This bold mix of flavors can overpower mild foods like poultry of fish, so cabernet sauvignon is best paired with richer foods like red meat, lamb or dark chocolate.