There are many reasons why cucumbers can have a bitter taste. While some cucumbers are grown specifically for their bitter taste, others can turn bitter from excessive heat, dry soil, or a lack of sunlight or water.
The bitterness of harvested cucumbers can be reduced by cutting a half inch off of each end of the vegetable before peeling. You can also rub the cut end’s skin against the inside of the cucumber and rinse off the foam it produces. These methods are known to remove cucurbitacins, the compound responsible for the bitter flavor.