Blossom ends not removed. Always remove blossom ends. Strong, bitter taste Spices cooked too long in vinegar, or too many spices used. Follow directions for amount of spices to use and the boiling time. Vinegar too strong.
Bitter taste is usually in the peeling.
Using salt substitutes. Potassium chloride ingredient in these is naturally bitter. Hollow pickles Cucumbers too large for brining. Use smaller cucumbers for brining. Keep brine proper strength and the product well-covered.