Yes, it is possible to make jam without using calcium water. You can make jam with just fruit, sugar, and pectin. Pectin is a natural gelling agent seen in many fruits and vegetables that will help the jam to set without needing calcium water. Additionally, you can use gelatin or agar-agar as an alternative to pectin if you do not have any on hand. When making jam without calcium water, you must be sure to use more sugar than if you were using calcium water since it helps the jam set properly and gives it a better texture. Also, ensure that your fruits are ripe for the best results. Finally, pay attention to the instructions on your recipe, as these will help you achieve perfect results every time!