Rich in antioxidants and high levels of anti-viral and anti-bacterial properties, blackberries -- a summer favorite -- is an excellent source of fiber and vitamin C. Low in calories and carbohydrates with no fat, blackberries are typically prominent in many healthy diets. However, the low level of sweetness of the fruit fails to cover the fruit's acidic harsh bite, ruining the appeal of eating the fruit raw for some. Fortunately, blackberries' bitterness is fairly easy to disguise or avoid.
Like strawberries and raspberries, blackberries are aggregate fruits or multiple fruits forming around a single flower's receptacle. A single blackberry is a cluster of drupes -- with each drupe bearing a seed -- connected to a receptacle or "stem." Unlike raspberries, where the receptacle stays attached to the plant when the berry is picked -- creating the cavity in the berry at the stem end -- the receptacle stays affixed to blackberries when picked. This is where the bitterness comes from.
Blackberry stems and leaves have high levels of salicylic and ellagic acids. While these chemicals are healthful -- salicylic acid is the active chemical in anti-acne medicine and aspirin and ellagic acid is thought to be toxic to cancer cells -- both acids are notably bitter in salt form. These acids are concentrated in the seeds and "stem."
Using Sugar to Hide the Bitterness
The easiest way to hide this bitterness is with sugar. Typically, it takes a half-cup of sugar to effectively disguise the bitterness of 2 cups of blackberries. Additionally, the bitterness can be hidden by eating the fruit with an item that contains a high level of fat, such as heavy cream. This doesn't, however, remove the bitterness, and a sensitive individual may be able to pick up on it, despite the camouflage. Many recipes are formulated to take advantage of this bitterness by contrasting it with matching sweetness, sourness and saltiness.
Dodging the Bitterness
By avoiding the stem and the seeds, you can side-step the bitterness entirely. By carefully pureeing or juicing the blackberries and straining, you can obtain a product that is significantly less bitter. Similarly, cooking blackberries mitigates the fruit's bitterness in part. The stringent qualities of the acids lessen when exposed to heat. Cooking blackberries, however, also reduces the health properties of the fruit.
Embracing the Bitterness
Possibly, the best way to deal with the bitterness is to accept that it's part of the fruit's flavor profile. While the fruit's bitter aftertaste is a concern to some diners, it is not the only fruit to possess this quality; strawberries -- another receptacle-keeping aggregate fruit -- also have a bitter aftertaste. Many people who love strawberries avoid the taste by avoiding the berry's bitter core. Similarly, by avoiding the blackberry's "core" while eating blackberries fresh, you can avoid much of the fruit's bitterness.